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The question people ask when treatment ends is whether the damage is permanent, and the answer is scattered across papers they will never see. This page gathers it: 116 sourced answers across 37 treatments and 18 lasting effects, filling 104 of the 666 squares in the grid, which is 15.6 per cent of it. 121 answers carry a proportion from the source, 23 published dose thresholds are listed separately, and 17 questions readers ask are written out as unanswered rather than left blank. The rest is empty because nothing was found to fill it: a blank here means unknown, never none. Trial and cohort populations differ from yours, so use this to know what to ask, not to decide a case.
Most people return to about where they started, in the timescale the source gives.
25 answers
Improvement is usual and complete recovery is not; a minority are left with something lasting.
60 answers
The damage is permanent in most people who get it, and the lever is prevention or replacement rather than recovery.
31 answers
The effect is recognised and no study found reports how often it recovers. Named here rather than left blank.
17 answers
One treatment at a time by default, because the grid is mostly empty and a reader should meet the answers before the holes. Switch to the grid to compare one effect across treatments. Every answer carries the source it was read from, and where the source gives a figure it is here with the cohort it came from.
The red chemotherapy drugs, given in most breast cancer, lymphoma, leukaemia and sarcoma regimens.
If the heart muscle weakens it nearly always shows up in the first year, and with heart failure treatment started promptly most people get some pumping strength back, though only about one in nine returns all the way to where they started.
When: median 3.5 months from the end of chemotherapy to the drop, and 98% of cases within the first year
How many: 11% full recovery (25 of 226) and 71% partial recovery (160 of 226) among those affected; overall incidence 9% (2,625 patients receiving anthracycline-containing therapy, prospective single-programme cohort, Italy)
“In 98% of cases (n=221), cardiotoxicity occurred within the first year. Twenty-five (11%) patients had full recovery, and 160 (71%) patients had partial recovery.”
Doxorubicin can stop sperm production, sometimes permanently; counts have come back to normal in some men, and the label says that can take several years.
When: sperm counts may return several years after the end of therapy
“Doxorubicin may result in oligospermia, azoospermia, and permanent loss of fertility. Sperm counts have been reported to return to normal levels in some men. This may occur several years after the end of therapy.”
The drop in infection-fighting white cells is temporary: it bottoms out about ten to fourteen days after a dose and has normally recovered by day twenty-one, in time for the next cycle.
When: low point 10 to 14 days after a dose, recovery usually by the 21st day
“A dose-dependent, reversible neutropenia is the predominant manifestation of hematologic toxicity from doxorubicin.”
The most powerful and the most toxic of the platinum drugs, used in testicular, lung, bladder and head and neck cancer.
Numbness and tingling in the hands and feet ease for many people after treatment stops, but about three in ten are still troubled by them a decade later, and severe cases can be permanent.
When: median follow-up 10.7 years, range 4 to 21 years
How many: 29% (95% CI 25% to 33%) reported paraesthesias in hands or feet as a major symptom (1,409 men treated for unilateral testicular cancer in Norway between 1980 and 1994, national multicentre survey)
“29% (95% CI = 25% to 33%) reported paresthesias in the hands or feet, 21% (95% CI = 18% to 25%) reported hearing impairment, and 22% (95% CI = 19% to 26%) reported tinnitus as major symptoms”
Nerve symptoms can start or worsen in the weeks after the last dose rather than improving straight away, a pattern clinicians call coasting, so an early dip is not the final answer.
“CIPN can progress from acute to chronic, may deteriorate even after treatment cessation (a phenomenon known as coasting) or only partially attenuate.”
Hearing loss from cisplatin does not come back, and in many people it keeps getting slowly worse for years after the last infusion, so the honest plan is lifelong hearing checks rather than waiting for recovery.
When: present from treatment onward and progressive afterwards
How many: 1061 of 1422 (75%) had audiometrically assessed ototoxicity (1,422 cisplatin-treated testicular cancer survivors at eight academic centres in the USA, Canada and the UK (The Platinum Study), median age 38)
“Cisplatin-induced ototoxicity is a permanent, bilateral sensorineural hearing loss occurring in up to 80% of treated patients.”
The licence is more cautious than the cohorts: it says it is unclear whether cisplatin hearing loss can reverse, and that the loss becomes more frequent and more severe with each further dose.
How many: up to 31% after a single 50 mg/m2 dose; 40 to 60% in children (the US prescribing information for cisplatin injection)
“Hearing loss can be unilateral or bilateral and tends to become more frequent and severe with repeated cisplatin doses. It is unclear whether cisplatin-induced ototoxicity is reversible.”
Searched: the licence itself states the question is unresolved; no cohort reporting recovery of cisplatin hearing loss in adults was found
Kidney function usually recovers enough to be safe, but on average a step down in filtration remains, and in a fifth to a third of people it is still measurably below normal more than ten years later.
When: measured four times across 14 years of follow-up, with the deficit still present beyond 10 years
How many: 14% reduction in renal function in the chemotherapy group (85 men with malignant germ-cell tumours (53 chemotherapy, 18 radiotherapy, 14 surgery), prospective, isotope-measured clearance)
“In the RAD group, renal function decreased by 8%, whereas a 14% reduction of renal function was observed in the CHEM group.”
Sperm production usually returns after cisplatin-based chemotherapy for testicular cancer, but it is slow: about half by two years and four in five by five years, and more than four cycles lowers the odds.
When: recovery continues well beyond one year; measured at 2 and 5 years
How many: probability of spermatogenesis 48% by 2 years and 80% by 5 years (178 men treated between 1979 and 1991 with sperm counts before and after chemotherapy at the Royal Marsden; 170 reassessed at least a year later)
“There was clear evidence for continued recovery beyond 1 year; the probability of spermatogenesis increased to 48% by 2 years and 80% by 5 years.”
Testosterone knocked down by testicular cancer treatment tends not to climb back, and the proportion of survivors with low levels rises as they age, so this is monitored for life rather than waited out.
When: 38.5% at a median age of 38
How many: 38.5% hypogonadal (491 North American testicular cancer survivors after modern platinum-based chemotherapy (The Platinum Study))
“Of 491 TCS (median age at assessment, 38.2 years; range, 18.7-68.4 years), 38.5% had hypogonadism.”
No source we could reach puts a figure on whether memory and concentration recover after cisplatin, so this page does not give one.
Searched: cisplatin with cognitive and survivors and testicular cancer; results were reviews of mechanism or quality-of-life surveys with no recovery proportion for cognition
Long-lasting tiredness after cisplatin-based treatment for testicular cancer does not fade with time; in the same men, it was commoner at nineteen years than at twelve.
When: first survey a median 12 years after treatment, second a median 19 years
How many: chronic fatigue rose from 15% to 27% (812 testicular cancer survivors treated between 1980 and 1994 in Norway, surveyed twice)
“Prevalence of CF increased from 15% at survey I to 27% at survey II”
The gentler platinum, dosed to kidney function and used where cisplatin would be too toxic.
Carboplatin causes nerve damage much less often than cisplatin, about one in six people against four in ten when the two were compared directly in the same trial.
How many: peripheral neuropathies 16% on carboplatin against 42% on cisplatin (the randomised NCIC trial in ovarian cancer, as tabulated in the approved carboplatin label)
“Non-hematologic toxicities (emesis, neurotoxicity, ototoxicity, renal toxicity, hypomagnesemia, and alopecia) were significantly more frequent in the cisplatin-containing arms.”
Carboplatin damages hearing far less often than cisplatin, roughly one in eight against one in three in a head-to-head trial, but no source we reached reports how often carboplatin hearing loss recovers.
How many: approximately 10 to 30% for carboplatin against 20 to 70% for cisplatin in children (narrative review of the 2019 to 2025 paediatric literature; the randomised NCIC ovarian trial in the carboplatin label gives ototoxicity in 13% against 33%)
“with reported incidence ranging from approximately 20-70% for cisplatin and 10-30% for carboplatin”
Searched: carboplatin and cisplatin ototoxicity comparison and incidence; no cohort reporting recovery or persistence of carboplatin hearing loss was found
Sperm production comes back more often after carboplatin-based chemotherapy than after cisplatin-based chemotherapy, in the one study that compared the two in the same men.
When: counts reassessed at least a year after chemotherapy, median 30 months
How many: significantly higher probability of recovery to oligospermic and normospermic counts with carboplatin (54 of 178 men with testicular germ cell cancer treated with carboplatin rather than cisplatin, Royal Marsden, 1979 to 1991)
“There was a significantly higher probability of recovery to OS and NS count levels in the 54 patients treated with carboplatin-rather than cisplatin-based therapy.”
Blood counts fall and then come back on their own: the low point is around day 21 and most people are back above the safety threshold by day 28, which is why cycles are spaced the way they are.
When: low point about day 21, recovery assessed at day 28
How many: by day 28, 90% have platelets above 100,000/mm3, 74% neutrophils above 2,000/mm3 and 67% leukocytes above 4,000/mm3 (patients receiving single-agent carboplatin, as reported in the approved label)
“By day 28, 90% of patients have platelet counts above 100,000/mm3; 74% have neutrophil counts above 2,000/mm3; 67% have leukocyte counts above 4,000/mm3.”
The platinum used in bowel and stomach cancer, with a cold-triggered nerve effect the others do not have.
The slow, cumulative numbness takes years to fade, and about one person in four still has some three years after adjuvant treatment ends.
When: measured at 6, 12, 24 and 36 months after chemotherapy
How many: pooled prevalence of any-grade neuropathy 58% at 6 months, 45% at 12 months, 32% at 24 months and 24% at 36 months (meta-analysis of 27 studies of adjuvant oxaliplatin for colorectal cancer, searched to March 2021)
“Pooled prevalence of CIPN at 6, 12, 24 and 36 months after chemotherapy were 58%, 45%, 32% and 24% respectively.”
The acute form, where cold air or a cold drink sets off tingling in the hands, mouth or throat, is reversible and clears within two weeks, though it returns with the next dose.
When: onset within hours or 2 days of a dose, resolving within 14 days
How many: acute reversible sensory neuropathy in about 56% of patients overall and about 30% in any one cycle (patients receiving oxaliplatin with fluorouracil and leucovorin, as reported in the approved label)
“Acute neuropathy typically presents as a reversible, primarily peripheral sensory neuropathy that occurs within hours or 2 days following a dose, resolves within 14 days, and frequently recurs with further dosing.”
In the trial that set the standard adjuvant regimen, severe nerve damage affected about one in eight people during treatment and about one in a hundred a year later.
When: during treatment, at 12 months and at 48 months
How many: grade 3 sensory neuropathy 12.4% during treatment, 1.1% at one year, and 0.7% at 48 months in the final report (the MOSAIC trial, 2,246 patients with resected stage II or III colon cancer)
“the incidence of grade 3 sensory neuropathy was 12.4 percent during treatment, decreasing to 1.1 percent at one year of follow-up”
Oxaliplatin is generally held to be much less damaging to hearing than cisplatin or carboplatin, and no human study gives a recovery figure either way; a 2026 mouse study argues it quietly injures the hearing nerve without changing the hearing test.
“It is generally accepted that oxaliplatin is significantly less ototoxic than the other platinum-based antineoplastic drugs, cisplatin and carboplatin.”
Searched: oxaliplatin and ototoxicity and hearing; no human cohort reporting oxaliplatin hearing outcomes or their recovery was found
Paclitaxel, docetaxel and their relatives, given in breast, lung, ovarian and prostate cancer.
Numbness and tingling from a taxane usually fade over the months after treatment, but about a third of the people who had moderate or severe symptoms at the end of docetaxel still have them one to three years later.
When: most improvement in the first 6 months; what remains at 1 to 3 years tends to stay
How many: 34% of those with grade 2 to 4 neuropathy at the end of treatment were still affected at 1 to 3 years (1,031 early breast cancer patients treated with docetaxel, Denmark)
“PN persisted for 1-3years among 81 (34%) while PN regressed to grades 0-1 among 160 (66%).”
Two years after starting a docetaxel-containing regimen, four in ten women still report some nerve symptoms, and more of the drug means more of the symptom.
When: measured at 2 years from the start of treatment
How many: 41.9% reported peripheral neuropathy at 2 years (1,512 women with node-positive early breast cancer in NSABP B-30)
“Of 1512 patients, 41.9% reported PN two years after treatment initiation.”
Periods stop during chemotherapy for most young women, and most get them back in the second year; taxane-containing regimens left more women without periods at a year than the same chemotherapy without one.
When: 36.2% still had no periods at 1 year and 17.2% at 2 years
How many: amenorrhoea at 1 year 286 of 789 (36.2%) and at 2 years 120 of 699 (17.2%); by regimen at 1 year, 44.1% after doxorubicin, cyclophosphamide and paclitaxel and 41.8% after docetaxel and cyclophosphamide against 25% after doxorubicin and cyclophosphamide alone (the Young Women's Breast Cancer Study, women diagnosed aged 40 or under, enrolled 2006 to 2016, several regimens)
“One year post-diagnosis, 286/789 (36.2%) experienced TRA, yet most resumed menses (2-year TRA: 120/699; 17.2%).”
Hair grows back after a taxane for most people, but in a substantial minority it comes back thinner and does not fully return, and three years on the picture has not improved.
When: assessed at 6 months and again at 3 years after chemotherapy
How many: 39.5% at 6 months and 42.3% at 3 years had persistent chemotherapy-induced alopecia (61 women with stage I to III breast cancer, prospective cohort, Samsung Medical Center, Seoul)
“The proportion of participants who had PCIA at 6 months and 3 years was 39.5% and 42.3%, respectively. PCIA was characterized in most patients by incomplete hair regrowth.”
Watering eyes on docetaxel usually settle, but if the tear ducts scar and the scarring is left alone it can become permanent, so this is worth reporting early.
When: stenting at the first sign of progressive narrowing prevents the permanent form
“silicone stenting at the first sign of recurrent or progressive canalicular stenosis can prevent severe irreversible canalicular stenosis”
Vincristine and its relatives, central to childhood leukaemia and lymphoma treatment.
Vincristine nerve damage improves after treatment stops for many adults, but half still have symptoms three months later and recovery is not complete for everyone.
When: symptoms peak by mid-treatment; half still present 3 months after the last dose
How many: 50% still reported neuropathy at 3 months after completion (57 adults assessed after vincristine, mean cumulative dose 7.6 mg, Australia)
“By 3 months post-completion, 50% of patients still reported VIPN although there were significant improvements on neurological grading and functional assessment”
Children treated for leukaemia mostly walk and run normally years later, but nerve testing still shows damage in two thirds of them and about one in six has symptoms a doctor can find as well.
When: measured 2.0 to 10.3 years after finishing chemotherapy
How many: 69 of 101 (68.3%) had electrophysiological evidence of neuropathy, and 16 (15.8%) had both clinical and electrophysiological neuropathy (101 Malaysian survivors of childhood acute lymphoblastic leukaemia aged 4 to 18)
“Twenty-seven (26.7%) had abnormal cTNS scores and 69 (68.3%) had electrophysiological evidence of neuropathy. Of these, 16 (15.8%) had combined clinical and electrophysiological neuropathy (VIPN).”
The most used alkylating drug, in breast cancer, lymphoma and transplant conditioning.
Very high doses of cyclophosphamide can weaken the heart within days, but in the published series the weakness reversed in everyone affected.
When: around the transplant, resolving clinically
How many: 6 of 61 women (10%) developed clinically reversible grade 3 congestive heart failure, with a median fall in ejection fraction of 31% (61 women with chemotherapy-responsive metastatic breast cancer given 96-hour infusional high-dose cyclophosphamide)
“Six of 61 women (10%) developed clinically reversible grade 3 CHF following infusional cyclophosphamide with a median percent decline in ejection fraction of 31%.”
Cyclophosphamide damages eggs and sperm in proportion to the total dose: about a quarter of men treated in childhood had no sperm at all when tested as adults, while most women kept their periods but faced a much higher chance of an early menopause.
When: men assessed a median 21 years after diagnosis
How many: azoospermia in 53 of 214 (25%) and oligospermia in 59 (28%); in women, non-surgical premature menopause 8% against 0.8% in siblings (St Jude Lifetime Cohort, men given alkylating agents without radiotherapy; Childhood Cancer Survivor Study, 2,819 female survivors and 1,065 sibling controls)
“Azoospermia was noted in 53 (25%) of 214 participants, oligospermia in 59 (28%), and normospermia (sperm concentration ≥15 million per mL) in 102 (48%) participants.”
If the ovaries fail outright within five years of diagnosis they do not restart; this happened to about one girl or young woman in sixteen in the largest survivor cohort.
When: defined as loss of ovarian function within 5 years of diagnosis
How many: 215 of 3,390 (6.3%) developed acute ovarian failure (female participants over 18 in the Childhood Cancer Survivor Study, excluding high-dose cranial irradiation and removal of the ovaries)
“Of a total of 3390 eligible survivors, 215 cases (6.3%) developed AOF.”
No study we could reach says what proportion of people regain normal immune function after cyclophosphamide, or how long it takes; the published work either studies it as part of transplant conditioning or does not name the drug the patients received.
Searched: cyclophosphamide with lymphopenia or lymphocyte; cyclophosphamide with hypogammaglobulinaemia, secondary immunodeficiency or immune recovery; CD4 recovery after chemotherapy
Bleeding from the bladder lining is common while on cyclophosphamide and usually settles when the drug stops, but a high lifetime total leaves a raised risk of bladder cancer that persists for years afterwards.
When: the cystitis is acute; the bladder cancer risk stays raised for years after the drug is stopped
How many: haemorrhagic cystitis in 12% to 41%, correlated with cumulative dose (systematic review of 18 studies in systemic autoimmune disease and vasculitis)
“Hemorrhagic cystitis is highly correlated with cumulative dose and its incidence ranges between 12 and 41%, but it seems to be lower with new regimens with reduced cyclophosphamide dose.”
Cyclophosphamide's relative, used in sarcoma and germ cell tumours, harder on the kidneys and the brain.
Most children treated with a moderate dose of ifosfamide have normal kidney function ten years later, but the damage that does happen can be permanent and can slowly worsen, so the kidneys are checked for life.
When: median follow-up 10 years, with damage still present at 10 years in those affected
How many: at a median 10 years, 89.5% had normal tubular function and 78.5% a normal glomerular filtration rate (183 children treated for sarcoma with ifosfamide, median dose 54 g/m2, and no platinum, assessed at least 5 years after treatment)
“After a median follow-up of 10 years, 89.5% of patients had normal tubular function, and 78.5% had normal glomerular function rate (GFR).”
When ifosfamide causes kidney failure in adults rather than mild leakiness of the tubules, a third of those people go on to end-stage kidney disease.
When: median follow-up 31 months
How many: 10 of 34 (29.4%) progressed to stage 5 chronic kidney disease and 6 (17.6%) needed haemodialysis (34 adults, median age 41, admitted to six French nephrology departments with ifosfamide nephrotoxicity; 44% had also had cisplatin)
“Ten patients (29.4%) progressed to Stage 5 CKD, six (17.6%) required haemodialysis and six patients died during a median follow-up period of 31 months.”
After an ifosfamide-based regimen for childhood rhabdomyosarcoma, about a third of men have damaged sperm production years later, and adding oral cyclophosphamide maintenance makes that worse.
When: median age at evaluation 18.7 years, median age at diagnosis 6.4 years
How many: exocrine gonadal dysfunction in 18 of 49 (37%) (male 5-year survivors of high-risk or very-high-risk localised rhabdomyosarcoma in the French arm of the RMS2005 trial)
“Twenty-six (53%) received oral-CPM (median cumulative dose = 4.2 g/m2, range = 0.7-9.0). EGD was reported in 18 of 49 (37%).”
Ifosfamide can cause sudden confusion or drowsiness during the infusion; it almost always clears within a few days of stopping the drug, and about a quarter of people get it again if ifosfamide is given once more.
When: mean time to resolution 2.58 days
How many: 20 of 215 patient cycles (9.3%) affected, with recurrence on re-challenge in 26.3% (51 adults with sarcoma receiving high-dose ifosfamide at a single centre)
“Twenty (9.3%) patient cycles included documented evidence of IIE. The most common management strategies were to prolong the infusion time and administer methylene blue. The mean time to resolution of IIE was 2.58 days.”
Melphalan, busulfan, bendamustine, temozolomide and the nitrosoureas, including the high doses used before a transplant.
Lung scarring from carmustine does not heal, and it can appear for the first time more than a decade after the treatment ended, especially in people treated as children.
When: deaths from fibrosis 2 within 3 years and 4 at 8 to 13 years; survivors studied at 13 to 17 years
How many: 6 of 17 survivors died of lung fibrosis, and all 8 studied later had restrictive lung function, mean vital capacity 54% of predicted (31 children treated with carmustine for brain tumours between 1972 and 1976)
“All the survivors studied had restrictive spirometric defects (mean [+/- SD] vital capacity, 54 +/- 19 percent of the predicted value).”
Busulfan used to prepare for a transplant damages the ovaries or testicles in roughly two thirds of children, and lowering the exposure did not reduce that risk.
When: assessed at or after the expected age of puberty
How many: gonadal dysfunction in 35 of 56 (63%) after busulfan and 9 of 32 (28%) after treosulfan (children and adolescents transplanted for non-malignant disease between 1997 and 2018, Netherlands)
“In the Bu group, 56 patients could be evaluated, and gonadal dysfunction was found in 35 (63%). Lower Bu exposure (ie, cumulative area under the curve [AUC] <70 mg*h/L) was not associated with a reduced risk”
After high-dose melphalan with a stem cell transplant the killer T cells come back within about three months, but the naive T cells that let you respond to something new take about eighteen months, and in older patients they may not return at all.
When: CD8 counts near normal by 3 months; naive CD45RA+ CD4 cells near normal only at 18 months
How many: naive CD45RA+ CD4 T cells approached the normal range only at 18 months and only in younger patients (71 women with high-risk or metastatic breast cancer given high-dose melphalan and etoposide with autologous stem cell support)
“Naive CD45RA + CD4 + T cells approached the normal range only 18 months after ASCT and only in younger patients.”
A sore mouth after high-dose melphalan affects about four in ten people badly, and it heals as the blood counts come back, over roughly five days.
When: mean duration of severe mucositis 5.3 days, tracking neutrophil engraftment
How many: severe oral mucositis in 44% (197 patients with myeloma or non-Hodgkin lymphoma having high-dose melphalan or BEAM and an autologous transplant at 25 European centres)
“SOM occurred in 44% of patients. The duration of SOM (mean 5.3 days) correlated with time to neutrophil engraftment.”
Busulfan is one of the few drugs reported to leave hair permanently thin: in a small series the regrowth was sparse, short and altered in texture, and the scalp biopsies showed the follicles had shrunk rather than scarred.
How many: 3 patients given busulfan for acute myelogenous leukaemia within a 10-case series of permanent alopecia (clinicopathological case series, 10 patients)
“10 cases of permanent alopecia after systematic chemotherapy with taxanes (docetaxel) for breast cancer (6 patients), busulfan for acute myelogenous leukemia (3 patients)”
Methotrexate given at high dose into a vein or directly into the spinal fluid, to treat or prevent disease in the brain.
About one person in four has a dip in kidney function after a high dose of methotrexate; it is nearly always mild and nine in ten recover.
When: resolution during or shortly after the cycle
How many: 76 of 281 (27.0%) developed acute kidney injury, 84.2% of it stage I, and 90.8% resolved (adults with haematological malignancies receiving their first cycle of high-dose methotrexate, 2020 to 2024)
“A total of 281 patients were included (Median age 44 years (range 18-82)), of whom 76 (27.0%) developed AKI, with 84.2% having stage I, and 90.8% achieved resolution.”
High-dose methotrexate leaves visible white matter changes on brain scans in most people and those changes often do not go away, but measured intelligence stays in the normal range and the one score that drops, processing speed, improves after treatment.
When: scans at 3 or more years after treatment were still abnormal in 20 of 24
How many: leukoencephalopathy on MRI in 44 of 53 (83%), still present in 20 of 24 scanned 3 or more years later (patients under 25 with osteosarcoma in the OS2006 study at Gustave Roussy, treated with high-dose methotrexate plus etoposide and ifosfamide)
“Among 24 patients with MRI ≥3 years post-treatment, 20 still showed leukoencephalopathy (12 Grade 1, eight Grade 2). Neurocognitive evaluations showed IQ scores consistent with norms, except for lower processing speed, which improved post-treatment.”
The backbone of leukaemia treatment, with effects on the balance centre of the brain at high doses.
High-dose cytarabine can cause unsteadiness and slurred speech, usually within the first week; it cleared completely in about three quarters of the people affected in the defining series, and those left with lasting problems were the ones whose symptoms were severe.
When: median onset 5 days, range 1 to 10
How many: neurotoxicity reversible in 16 of 21 survivors (76%), affecting 26 of 147 treatment courses (18%) (101 patients with acute leukaemia receiving high-dose cytarabine at a single institution)
“Twenty-six treatment courses (18%) were complicated by NT. The median time of NT onset was 5 days (range, 1 to 10 days), and NT was reversible in 16 of 21 survivors (76%).”
No study we could reach gives a figure for how far the immune system recovers after cytarabine, or how long it takes; the only sustained-lymphopenia data found is in mice.
Searched: cytarabine with lymphopenia, immune reconstitution or infection; immune recovery after autologous transplant with melphalan or BEAM
Sore, streaming, light-sensitive eyes are common on high-dose cytarabine; the symptoms go within days and the cloudiness on the cornea clears over about a month.
When: symptoms resolved over four days, vision over two weeks, corneal cloudiness by four weeks
How many: kerato-conjunctivitis in 41 of 53 (77.4%) even with steroid eye drops (adults given cytarabine 3 g/m2 twice daily for 4 days as transplant conditioning)
“Symptoms gradually resolved over the following four days; however, impaired visual acuity persisted for two weeks and corneal opacification did not disappear until four weeks following therapy.”
Part of curative treatment for Hodgkin lymphoma and testicular cancer, and the drug that scars lungs.
Lung inflammation affects about one person in fifteen treated for a germ cell tumour and kills about one in a hundred of those treated, which is why a new cough or breathlessness is reported at once.
When: median 4.2 months from the start of bleomycin to documented lung toxicity
How many: 57 of 835 (6.8%) had bleomycin pulmonary toxicity, with 8 deaths, 1% of those treated (835 men treated with bleomycin-containing regimens for germ-cell tumours at the Royal Marsden, 1982 to 1999)
“Fifty-seven (6.8%) patients had BPT, ranging from X-ray/CT (computed tomography) changes to dyspnoea. There were eight deaths (1% of patients treated) directly attributed to BPT.”
In men cured of testicular cancer with three or four courses including bleomycin, lung function measured six to twelve years later was no different from men who had surgery alone.
When: 6 to 12 years after treatment
How many: forced vital capacity, FEV1 and carbon monoxide transfer factor all within normal limits in both groups (two matched groups of 47 men after retroperitoneal lymph node dissection, one group also given bleomycin and cisplatin)
“We conclude that 3-4 courses with bleomycin, cisplatin and etoposide/vinblastine in testicular cancer patients do not lead to long-term impairment of pulmonary function.”
Skin reactions are the commonest side effect of bleomycin, affecting about half of people; they appear late, in the second or third week, and are tied to how much drug has been given, and the licence does not say how often the skin returns to normal.
When: usually developing in the second and third week of treatment
How many: reactions of the skin and mucous membranes in approximately 50% of treated patients, with treatment stopped for them in 2% (patients treated with bleomycin, as reported in the approved label)
“These adverse reactions have been reported in approximately 50% of treated patients. They consist of erythema, rash, striae, vesiculation, hyperpigmentation, and tenderness of the skin.”
Trastuzumab and pertuzumab, given with or after chemotherapy in HER2-positive breast and stomach cancer.
If trastuzumab weakens the heart's pumping, stopping the drug and starting heart medication brings it back for roughly half to two thirds of people, but not for everyone.
When: ejection fraction checked every 3 months during treatment and every 6 months afterwards
How many: 25 of 42 with cardiotoxicity recovered; recovery was 35% in those whose troponin had risen and 100% in those whose had not (251 women on trastuzumab for breast cancer, Milan)
“TIC occurred in 42 patients (17%) and was more frequent in patients with TNI elevation (TNI+; 62% v 5%; P < .001). Twenty-five patients (60%) recovered from TIC.”
Brentuximab vedotin, enfortumab vedotin and polatuzumab vedotin: the antibody carries a microtubule poison that also reaches nerves.
Numb or tingling hands and feet from these drugs improve for most people but completely go away for only a minority: on enfortumab vedotin, nearly nine in ten still had some neuropathy at their last assessment.
When: median time to grade 2 or worse neuropathy 4.9 months on enfortumab vedotin alone
How many: 11% complete resolution and 89% residual neuropathy on enfortumab vedotin; on brentuximab vedotin with AVD, 36% resolved and a further 33% improved (296 enfortumab vedotin recipients with resolution data; 153 patients on brentuximab vedotin plus AVD across 10 United States institutions)
“Of the patients who experienced neuropathy who had data regarding resolution (n=296), 11% had complete resolution, and 89% had residual neuropathy at the time of their last evaluation.”
Rashes are very common with enfortumab vedotin and occasionally severe, but no study reports what proportion clear completely, so this page cannot say how often the skin fully recovers.
How many: 206 of 449 patients developed a skin reaction and 39 of those were high grade, with resolution not measured (patients with urothelial carcinoma on enfortumab vedotin)
Searched: enfortumab with neuropathy, skin or cutaneous; the label gives management rules and discontinuation rates but no resolution proportion
Trastuzumab deruxtecan and sacituzumab govitecan: a different payload, with the lung as the organ to watch.
About one in eight people on trastuzumab deruxtecan gets lung inflammation; most recover, but around one in thirteen of those cases was fatal, which is why a new cough or breathlessness is reported at once.
When: median time to first onset 5.1 months in the Japanese surveillance, with fatal cases beyond 12 months
How many: of 381 adjudicated cases, 78.2% were grade 1 or 2, overall recovery was 83.5%, and 30 patients (7.9%) had grade 5 disease (2,801 patients in Japanese post-marketing surveillance with breast or gastric cancer)
“Most cases (78.2%) were worst CTCAE Grade 1-2. Grade 5 ILD occurred in 30 patients (7.9%), with DAD the most common pattern (26 patients). Overall recovery was 83.5%.”
Mouth soreness and ulcers are a recognised side effect of trastuzumab deruxtecan, but no source states what proportion resolve, so this page cannot say how often the mouth fully settles.
How many: stomatitis in 10% to 23% of patients depending on the trial, with grade 3 or 4 in 0.2% to 1.3%, and no resolution figure given (the trial programme tabulated in the US label)
Searched: trastuzumab deruxtecan with stomatitis or oral toxicity; the label records incidence only
Trastuzumab emtansine and mirvetuximab soravtansine, whose characteristic effects are on the liver, the platelets and the surface of the eye.
Lung inflammation on trastuzumab emtansine is rare, affecting about one person in a hundred, but no source states how many recover, because the drug is stopped for good and the lung outcome is not followed as a trial endpoint.
How many: pneumonitis in 0.8% (7 of 884) in metastatic breast cancer and 1.1% (8 of 740) in KATHERINE, with no resolution figure (the trastuzumab emtansine trial programme)
Searched: trastuzumab emtansine with interstitial lung disease or pneumonitis; the label records incidence and permanent discontinuation, not outcome
Most nerve symptoms on trastuzumab emtansine are mild and sensory, and most clear, but in the adjuvant trial about a third had not resolved by the time the main analysis was done.
When: assessed at the primary invasive-disease-free-survival analysis of KATHERINE
How many: 30% of peripheral neuropathy cases were not resolved; overall incidence 32% in KATHERINE and 21% in EMILIA (740 patients on trastuzumab emtansine in KATHERINE and 1,624 across the trial programme)
“Peripheral neuropathy, including sensory and motor peripheral neuropathy, for KADCYLA treated patients 30% of cases were not resolved at the time of the primary IDFS analysis for KATHERINE.”
Blurred vision and corneal surface changes affect about half of people on mirvetuximab, and in the pooled trial data every moderate or worse case settled back to mild or none with eye drops and dose adjustment.
When: managed with lubricating drops daily and corticosteroid drops periodically, with eye examinations every other cycle for the first eight cycles
How many: 50% had blurred vision or keratopathy, 5% grade 3 and one patient grade 4; all grade 2 or worse events resolved to grade 1 or 0 where follow-up was complete (pooled safety analysis of 464 mirvetuximab-treated patients across three trials)
“All grade ≥2 AEIs of blurred vision and keratopathy resolved to grade 1 or 0 in patients with complete follow-up data.”
Ibrutinib, acalabrutinib and zanubrutinib, taken daily for years in chronic lymphocytic leukaemia and some lymphomas.
Raised blood pressure on ibrutinib is very common and settles again once the drug is stopped; the irregular heartbeat it can cause is a separate matter and may persist.
When: new or worsened hypertension over a median 30 months of ibrutinib, with reversibility assessed at five years
How many: new or worsening hypertension in 78.3% (562 consecutive ibrutinib recipients treated between 2009 and 2016, with a five-year follow-up analysis in 300 patients with chronic lymphocytic leukaemia)
“Hypertension was reversible after ibrutinib discontinuation.”
Palbociclib, ribociclib and abemaciclib, taken with hormone therapy in breast cancer.
Lung inflammation on a CDK4/6 inhibitor is uncommon and usually resolves once the drug is stopped and steroids are given, but a small number of deaths have been recorded.
When: most cases began within 180 days of starting abemaciclib
How many: interstitial lung disease in 5.0% (59 of 1,189) with death in 0.7%; in a prospective cohort 9 of 122 developed it and all were in remission or cured (a Japanese nested case-control study across 77 institutions, and a separate prospective multicentre cohort of 122 patients)
“All cases of ILD ultimately were confirmed to be in remission or cured.”
The drop in white cells on a CDK4/6 inhibitor is expected, short-lived and reverses between cycles, which is why the dose is paused rather than the drug abandoned.
When: first episode at a median of 15 days, with severe episodes lasting a median of 7 days
How many: any-grade neutropenia in 80% and 83% of patients, grade 3 or worse in 66% (PALOMA-2, 666 patients, and PALOMA-3, 517 patients)
“In PALOMA-2 and PALOMA-3, the median time to first episode of any grade neutropenia was 15 days and the median duration of Grade ≥3 neutropenia was 7 days”
Olaparib and its relatives, taken daily in ovarian, breast, prostate and pancreatic cancer with a DNA repair fault.
A small number of people on PARP inhibitors develop a bone marrow cancer, which is permanent harm rather than something that recovers, and it is often fatal.
When: a median 9.8 months of PARP inhibitor treatment before diagnosis, and a median latency of 17.8 months from first exposure
How many: 0.73% across PARP inhibitor arms against 0.47% on placebo, and 47 of 104 reported cases ended in death (meta-analysis of 18 placebo-controlled randomised trials, 7,307 patients, with 178 pharmacovigilance cases)
“Of 104 cases that reported outcomes, 47 (45%) resulted in death.”
PARP inhibitors clearly make fatigue more likely, but no study has followed people after stopping the drug to say what proportion get their energy back, so this page gives no recovery figure.
How many: relative risk 1.24 for any-grade fatigue and 1.71 for high-grade fatigue, measured while on treatment only (meta-analysis of 9 randomised trials in 2,074 patients)
Searched: fatigue with olaparib, niraparib or PARP inhibitor; the label records incidence during treatment only
Pembrolizumab, nivolumab, ipilimumab and their relatives, which take the brakes off the immune system.
Myocarditis from immunotherapy is rare but serious: survivors can recover heart function, yet the risk of dying stays roughly doubled for a year afterwards and is still raised at five years.
When: mortality measured at 1 year and 5 years
How many: one-year mortality 38.9% after checkpoint-associated myocarditis against 20.8% in matched myocarditis of other causes, and 47.8% against 34.3% at five years (matched cohorts in a federated health records network, 226 patients with checkpoint-associated myocarditis)
“One- and 5-year mortality was greater for pericarditis (44.3% versus 37.3%; 54.3% versus 46.9%), myocarditis (38.9% versus 20.8%; 47.8% versus 34.3%)”
Immunotherapy pneumonitis usually clears with steroids and seldom becomes permanent, but it comes back in roughly one in twelve people, and more often in those who already had scarred lungs.
How many: recurrence 8.3% with no prior lung disease, 9.1% with chronic obstructive pulmonary disease and 16.4% with pre-existing interstitial lung disease (matched cohorts of 3,147 patients each, drawn from more than 184,000 checkpoint inhibitor recipients in a federated health records network)
“ILD patients with CIP had higher recurrence (16.4% vs. 9.1% and 8.3%) and higher all-cause hospitalisation (61% vs. 40% and 39%) compared to COPD and control groups.”
Nerve problems caused by immunotherapy are among the toxicities most likely to stay after treatment ends, and about three quarters of them became long-term.
When: chronic defined as persisting beyond 12 weeks after the drug was stopped
How many: 11 of 15 neurotoxicities became chronic (387 patients given adjuvant anti-PD-1 for stage III to IV melanoma at eight academic centres)
“Endocrinopathies (73 of 88; 83.0%), arthritis (22 of 45; 48.9%), xerostomia (9 of 17; 52.9%), neurotoxicities (11 of 15; 73.3%), and ocular events (5 of 8; 62.5%) were particularly likely to become chronic.”
If immunotherapy inflames the pituitary, the gland's control of the adrenal glands almost never comes back, so steroid replacement is usually for life, though the thyroid and sex-hormone axes recover in some people.
When: onset at a median of 13 weeks, after the third cycle, with no recovery of the adrenal axis during follow-up
How many: none of 22 recovered secondary adrenal insufficiency; the thyroid axis recovered in 33% and the gonadal axis in 67% (22 patients with checkpoint-induced hypophysitis at a tertiary endocrine and immunotherapy clinic)
“None recovered SAI during follow-up, whilst recovery of SH and SHG was noted in 33% and 67%, respectively.”
Thyroid inflammation from immunotherapy often burns the gland out, and when it does the thyroid does not restart, so levothyroxine is usually lifelong.
When: the overactive phase comes first, at a median of 42 days from the first dose in those who went on to permanent underactivity
How many: only 2 of 103 regained their own thyroid function, while 64 reached normal levels on levothyroxine; in a separate cohort 53 of 124 progressed to permanent hypothyroidism (103 patients with checkpoint-associated thyroiditis at an academic centre, and 124 at Montefiore between 2016 and 2021)
“Sixty-six of the 103 patients achieved euthyroid state; 2 with intrinsic thyroid gland function recovery and 64 on LT4.”
Adrenal insufficiency caused by immunotherapy generally does not reverse, and people are still taking replacement steroids years after the immunotherapy itself has finished.
When: still on replacement steroids at a median follow-up of 1,057 days from the start of treatment
How many: of 93 patients whose immune side effects were still present at last follow-up, 24 (25.8%) were on systemic steroids, 16 of them replacement for hypophysitis or adrenal insufficiency (318 patients given adjuvant anti-PD-1 for resected melanoma at six centres in the United States and Australia)
“24 (25.8%) were using therapeutic systemic steroids (16 [67%] of whom were on replacement steroids for hypophysitis (8 [50.0%]) and adrenal insufficiency (8 [50.0%])”
Diabetes caused by immunotherapy destroys the insulin-making cells, and in the largest published series not one person came off insulin.
When: onset at a median of 2.4 months from the start of immunotherapy, with insulin dependence continuing to the end of follow-up
How many: all 34 remained insulin-dependent (CANDIED, five Canadian cancer centres, patients on anti-PD-1 or anti-PD-L1 based therapy)
“All patients remained insulin-dependent at the end of follow-up.”
A dry mouth brought on by immunotherapy persisted in about half of the people who developed it, which is unlike most of the other non-hormonal effects.
When: chronic defined as persisting beyond 12 weeks after the drug was stopped
How many: 9 of 17 cases of dry mouth became chronic (387 patients given adjuvant anti-PD-1 for stage III to IV melanoma at eight academic centres)
“xerostomia (9 of 17; 52.9%)”
Immunotherapy colitis usually settles and rarely becomes a long-term problem, and most of the few cases that do drag on eventually clear.
When: chronic defined as persisting beyond 12 weeks after the drug was stopped
How many: colitis became chronic in 6 of 44, and 4 of those 6 later resolved (387 patients given adjuvant anti-PD-1 for stage III to IV melanoma at eight academic centres)
“colitis became chronic in 6 of 44 (13.6%) cases, of which 4 of 6 (66.7%) resolved with prolonged follow-up”
Immunotherapy rashes almost always improve once they are treated or the drug is paused, though a minority of people are left with a grumbling dermatitis after treatment ends.
When: a maculopapular rash began within one month in more than half of cases, and lichenoid eruptions at 4 to 8 months
How many: 50 of 51 biopsy-confirmed skin reactions improved (51 patients with histopathologically diagnosed cutaneous immune-related adverse events, Kyushu University Hospital, 2014 to 2020)
“With appropriate treatment and/or interruption of ICIs, most rashes improved (50/51, 98.0%).”
Eye inflammation from immunotherapy is uncommon, but when it happens it is more likely than not to persist after treatment stops; the numbers behind that are small.
When: chronic defined as persisting beyond 12 weeks after the drug was stopped
How many: 5 of 8 ocular events became chronic (387 patients given adjuvant anti-PD-1 for stage III to IV melanoma at eight academic centres)
“ocular events (5 of 8; 62.5%) were particularly likely to become chronic”
Your own T cells, re-engineered to attack a marker on the cancer and given back once.
No published study gives a figure for how many people recover fertility after CAR-T; pregnancies and live births have been reported, but no cohort has measured who could conceive and who could not.
How many: not reported (the largest European survey counted 24 pregnancies in 19 patients across 99 centres, with no denominator of patients trying to conceive)
Searched: fertility, gonadal function or ovarian reserve with CAR-T or chimeric antigen receptor; anti-Mullerian hormone after CAR-T
The confusion, word-finding trouble and tremor that can follow CAR-T almost always settle within a few weeks, but a small number of people have a much longer course and some are left with attention and processing problems.
When: median onset 4 days and median duration 17 days in large B-cell lymphoma, with prolonged cases recorded
How many: not reported as a proportion; the label records encephalopathy lasting up to 173 days (the axicabtagene ciloleucel trials, 422 patients with non-Hodgkin lymphoma)
“The median time to onset was 4 days (range: 1 to 43 days) and the median duration was 17 days in patients with LBCL in Study 2.”
CAR-T aimed at B cells strips out the cells that make antibodies, so most people end up with low immunoglobulins, and for many that is still true more than a year later.
When: moderate to severe low IgG persisted beyond 12 months after BCMA CAR-T
How many: hypogammaglobulinaemia in about 90% after CD19 CAR-T; after BCMA CAR-T it persisted beyond 12 months in 99 of 145 (579 CD19 CAR-T recipients and 147 BCMA CAR-T recipients in one United States health system)
“Moderate to severe hypogammaglobulinemia was present <3 months post-CAR-T in 66/106 (62%) and persisted for >12 months in 99/145 (68%).”
Blood counts often stay low for weeks or months after CAR-T, and when the drop is severe it carries a real risk of serious infection and of dying without the cancer coming back.
When: severe neutrophil counts had not recovered by day 30 in 39% of recipients
How many: severe prolonged cytopenia was followed by severe infection in 49% against 13%, and non-relapse mortality of 14% against 4% (549 patients given BCMA- or CD19-directed CAR-T for myeloma, large B-cell lymphoma or mantle cell lymphoma)
“Severe ICAHT was associated with a higher rate of severe infections (49% vs 13%, P < .0001), increased nonrelapse mortality (14% vs 4%, P < .0001)”
Antibodies with one arm on the cancer and one on a T cell, given on a continuing schedule.
Confusion or trouble writing during the first doses of a T-cell engager is uncommon and usually passes within a few days.
When: median onset 4 days after the most recent dose, median duration 3 days, range 1 to 20 days
How many: immune effector cell-associated neurotoxicity in 6% on teclistamab alone and 1.1% when combined with daratumumab (MajesTEC-1 and MajesTEC-3)
“The median time to onset of ICANS was 4 days (range: 2 to 8 days) after the most recent TECVAYLI dose with a median duration of 3 days (range: 1 to 20 days).”
T-cell engagers suppress antibody production for as long as you keep taking them, so infections are common and most people need immunoglobulin replacement; no study has measured whether antibody levels recover after stopping.
When: infection rates measured over a median 21 months on teclistamab
How many: severe infections fell from 0.93 to 0.33 per patient-year on immunoglobulin replacement (80 patients with relapsed or refractory myeloma on teclistamab at a single centre)
“Treatment with IVIG resulted in significantly lower rates of both severe infections (0.33 vs. 0.93 per patient-year) as well as of all-grade infections (3.15 vs. 4.41 per patient-year).”
Searched: hypogammaglobulinaemia recovery or immunoglobulin recovery after stopping a bispecific antibody; no cohort reports antibody levels after the drug is stopped
Treatment that removes testosterone, the backbone of prostate cancer treatment beyond the prostate.
Pooled randomised trials did not find more deaths from heart disease in men given hormone treatment, so for most men there is no lasting heart injury to recover from, though observational studies disagree and the question is not closed.
How many: cardiovascular death 11.0% with androgen deprivation against 11.2% without (4,141 patients in 8 randomised trials in non-metastatic prostate cancer)
“ADT use was not associated with an increased risk of cardiovascular death but was associated with a lower risk of PCSM and all-cause mortality.”
Testosterone comes back for most men after a short course, but it is slow, and getting back to the exact level you started at is much less common than simply getting out of the castrate range.
When: after a course of about 4 months, a median 3.2 months to above castrate, 4 months to a non-hypogonadal level and 12.1 months to a normal level
How many: by 12 months 98.1% reached non-castrate levels, 79.5% returned to normal and 33.9% to their own baseline (64 men given 3 months of neoadjuvant androgen blockade before prostatectomy, secondary analysis of a phase 2 trial)
“By 12 months, 98.1% of patients reached non-castrate levels, 79.5% returned to normal, and 33.9% to BTB.”
The longer the treatment runs, the worse the odds of recovery, and a minority of men never come out of the castrate range at all.
How many: roughly one sixth of men remained castrate, and courses longer than 12 months with a GnRH agonist had lower rates of partial recovery (388 men who completed a finite course of androgen deprivation, single health system records)
“T recovery after ADT is variable with roughly one sixth of men remaining castrate.”
Bone density falls steadily while you are on hormone treatment; the only evidence that it climbs back after stopping comes from one small study, so recovery here is likely but not established.
When: loss measured every 6 months over 2 years of treatment
How many: bone density fell 3.8% at the femoral neck, 4.2% at the total hip and 6.1% at the lumbar spine over 2 years (34 men with prostate cancer without bone metastases, Kobe University Hospital)
“Significant declines in BMD (-3.8% for femoral neck, -4.2% for total hip, and -6.1% for lumbar spine) and TBS (-16.6%) were noted after 2 years of ADT.”
No source we could reach reports what happens to thinking and memory after hormone treatment stops; the controlled studies that exist disagree about whether there is a measurable deficit during treatment at all.
Searched: androgen deprivation with cognitive and controlled or prospective; androgen deprivation with cognitive and meta-analysis
Testosterone returning to normal does not mean sexual function returns with it; erections and sexual quality of life lag behind the blood test, and for some men they do not catch up.
When: sexual scores still significantly worse than in men not given hormone treatment at 36 months, while testosterone matched the comparison group by 12 months
How many: no proportion stated (139 men given brachytherapy, 41 of them with neoadjuvant androgen deprivation of about 4 months)
“Persistent sexual dysfunction occurs despite the normalization of testosterone levels post-ADT.”
Energy and overall quality of life climb back during a break from treatment, tracking the return of testosterone, but they recover more slowly than they fell and older men recover least.
When: maximum recovery of quality of life most often reached at 9 to 12 months off treatment
How many: no proportion stated (250 men on an intermittent androgen blockade programme, assessed every 3 months for 30 months)
“Maximum recovery of HQOL occurred most frequently by months 9-12.”
Letrozole, anastrozole and exemestane, taken for five to ten years after breast cancer in women past the menopause.
The bone loss caused by an aromatase inhibitor is partly reversible: the spine starts gaining density again once you stop, and the extra fracture risk disappears after treatment ends.
When: measured between year 5 and year 7, the two years after treatment stopped
How many: lumbar spine density rose 1.25% after anastrozole was withdrawn in women with normal baseline density (528 women in the IBIS-II prevention trial bone substudy who did not receive risedronate)
“Our results show that the negative effects of anastrozole on BMD in the preventive setting are partially reversible.”
Joint and muscle pain on an aromatase inhibitor is very common and lasts for years while you take the drug, but no source we could reach gives the proportion whose pain resolves after the course ends, or how long that takes.
How many: 85.9% reported joint or muscle pain at least once, 68.5% at year 2 and 65.4% at year 4 (4,854 postmenopausal women on adjuvant aromatase inhibitors in the CANTO cohort)
Searched: aromatase inhibitor with musculoskeletal symptoms and discontinuation or resolution; aromatase inhibitor arthralgia and reversible
The oldest targeted cancer medicine, blocking oestrogen at the breast while acting like it elsewhere.
The menopausal side effects of tamoxifen are a feature of taking it rather than a lasting change: in the prevention trial most side effects stopped once the five years were over, while the protection against cancer carried on.
When: side effects compared during the 5-year treatment period and after it
How many: no proportion stated for hot flushes (7,145 women aged 35 to 70 at increased risk in the IBIS-I randomised prevention trial, 96-month follow-up)
“The risk-reducing effect of tamoxifen appears to persist for at least 10 years, but most side effects of tamoxifen do not continue after the 5-year treatment period.”
The raised risk of blood clots is confined to the years you are taking tamoxifen; once you stop, the rate falls back to the same as in women who never took it.
When: measured during 5 years of treatment and in the follow-up after it
How many: deep-vein thrombosis and pulmonary embolism in 52 against 23 cases during treatment, and 16 against 14 cases after stopping (7,145 women in the IBIS-I randomised prevention trial)
“but not after tamoxifen was stopped (16 versus 14 cases, RR = 1.14, 95% CI = 0.52 to 2.53)”
Tamoxifen retinopathy is uncommon, and stopping the drug does not reliably restore sight: in a documented case the retina partly repaired itself over ten months while the vision stayed poor.
When: 10 months of follow-up after the drug was stopped
How many: a single reported case (one woman of 35 after 3.75 years of low-dose tamoxifen)
“At the 10-month follow-up, there was partial structural improvement, yet ellipsoid layer impairment persisted.”
Treatment of the breast, the lung or the lymph nodes in the middle of the chest.
Radiation dose to the heart raises the rate of heart attacks in direct proportion to the dose, there is no safe level below which the effect disappears, and the risk does not fade with time.
When: the increase started within the first 5 years and continued into the third decade after radiotherapy
How many: 7.4% more major coronary events per gray of mean heart dose (2,168 women irradiated for breast cancer in Sweden and Denmark between 1958 and 2001)
“Rates of major coronary events increased linearly with the mean dose to the heart by 7.4% per gray (95% confidence interval, 2.9 to 14.5; P<0.001), with no apparent threshold.”
The early inflammation of radiation pneumonitis usually settles, but if it turns into scarring of the lung that scarring is permanent and the loss of lung function does not come back.
How many: radiation-induced lung injury occurs in up to 30% of patients having radiotherapy to the chest (review of patients receiving thoracic radiation therapy)
“Patients who develop lung fibrosis have a reduced quality of life with progressive and irreversible organ malfunction.”
About one woman in six develops arm swelling after breast cancer treatment, and the risk is roughly four times higher after a full armpit clearance than after a sentinel node biopsy; the evidence base reports how often it starts, not how often it goes away.
When: incidence seemed to increase up to 2 years after diagnosis or surgery
How many: pooled incidence 16.6%, and 19.9% after axillary lymph node dissection against 5.6% after sentinel node biopsy (72 studies in a systematic review and meta-analysis of breast cancer survivors)
“72 studies met the inclusion criteria for the assessment of lymphoedema incidence, giving a pooled estimate of 16.6% (95% CI 13.6-20.2).”
Hardening of the breast, shrinkage, swelling and fine broken veins are recorded as late effects a decade after treatment, and how common they are depends on the dose given in each session; the trials report no figure for them resolving.
When: median follow-up 9.3 years and 9.9 years in the two trials
How many: no proportion stated in the abstract (2,236 women in START-A and 2,215 in START-B, UK randomised trials)
“In START-B, breast shrinkage, telangiectasia, and breast oedema were significantly less common normal tissue effects in the 40 Gy group than in the 50 Gy group.”
The tiredness of radiotherapy builds through the course and then fades, and by three months most women are back to how they felt before treatment started.
When: measured before radiotherapy, at the end of it, and at 3, 6 and 12 months
How many: mean fatigue score rose 8.3 points during radiotherapy on a 0 to 100 scale, then returned to pre-treatment levels (250 Norwegian women having post-operative radiotherapy for breast cancer, with 652 general population controls)
“The level increased during RT (mean change 8.3, 95% CI 5.5-11.1), but declined thereafter and did not differ significantly from pre-treatment levels at subsequent time points.”
Treatment of the mouth, throat, voice box or neck nodes, through which the salivary glands and the thyroid sit.
Hearing loss from radiation to the inner ear is nerve damage and is not reported to recover; how much you lose tracks the dose the cochlea received.
When: assessed before treatment and over two years of follow-up
How many: no proportion stated; hearing loss was significantly worse above 45 Gy to the cochlea (130 patients with head and neck cancer, 56 radiotherapy alone and 74 chemoradiation)
“We observed that patients who received >45 Gy of radiation had more sensorineural hearing loss compared to patients who received <45 Gy.”
An underactive thyroid is a common late consequence of radiotherapy to the neck, it usually appears within the first year or two, and the published work measures how often it happens and who needs thyroid tablets rather than how often the gland recovers.
When: cumulative incidence 24.5% at 1 year and 38.7% at 2 years, median onset 10.0 months
How many: median estimated incidence across studies 36%, range 3% to 79% (111 articles in a systematic review of adults having radiotherapy for head and neck cancer)
“There was a large variation in the estimated incidence of RT-related hypothyroidism, with a median estimate of 36% (range 3% to 79%).”
Dry mouth improves over the second year as the spared glands start producing again, but in the trial that deliberately avoided the parotids three in ten people still had moderate or worse dry mouth two years on, and with conventional radiotherapy more than eight in ten did.
When: assessed at 12 and 24 months, with spared glands recovering flow during the second year
How many: moderate or worse dry mouth at 24 months in 29% with parotid-sparing IMRT against 83% with conventional radiotherapy (94 patients with pharyngeal squamous-cell carcinoma in the PARSPORT randomised trial, six UK centres)
“At 12 and 24 months, significant benefits were seen in recovery of saliva secretion with IMRT compared with conventional radiotherapy”
Swallowing solid food improves steadily and about three quarters of people are back to what they could eat before treatment at five years, though roughly a quarter are measurably worse on a swallowing study even when they say they are managing.
When: measured between 6 months and 5 years after chemoradiotherapy
How many: patient-reported swallowing returned to pre-treatment levels for 74% of patients, while up to 24% showed a clinically significant deterioration at 5 years (39 patients with patient-reported data and 21 with videofluoroscopy, from a cohort of 69)
“Between 6 months and 5 years posttreatment, patient-reported activity for solid foods significantly improved (p < .001), returning to pretreatment levels for 74% of patients.”
Treatment of a brain tumour, of secondary deposits, or of the whole brain to prevent them.
Severe hearing loss affected close to one ear in five when brain radiotherapy was combined with cisplatin, and it worsened with the dose the cochlea received; the chemotherapy and the radiation cannot be separated in this cohort.
When: median audiogram follow-up 41 months
How many: severe ototoxicity in 18.2% of ears (44 children with medulloblastoma treated with craniospinal irradiation, an IMRT boost and cisplatin-based chemotherapy)
“Severe ototoxicity was seen in 18.2% of ears in children treated with IMRT boost and cisplatin-based chemotherapy.”
Pituitary hormone failure after cranial radiotherapy does not recover, it keeps appearing for decades afterwards, and in a large survivor cohort nearly half had growth hormone deficiency.
When: cohort observed for a mean 27.3 years, with cumulative incidence rising over time
How many: growth hormone deficiency 46.5%, gonadotrophin deficiency 10.8%, thyroid-stimulating hormone deficiency 7.5% and adrenocorticotropic hormone deficiency 4% (748 adult survivors of childhood cancer treated with cranial radiotherapy, St Jude Lifetime Cohort)
“The estimated point prevalence was 46.5% for GHD, 10.8% for LH/FSHD, 7.5% for TSHD, and 4% for ACTHD, and the cumulative incidence increased with follow-up.”
Whole-brain radiotherapy causes cognitive decline in the great majority of people within three months, and steering the dose away from the memory structures reduces how many decline without preventing it.
When: cognitive deterioration measured at 3 months
How many: deterioration at 3 months in 91.7% given radiosurgery plus whole-brain radiotherapy against 63.5% given radiosurgery alone (213 patients with 1 to 3 brain metastases randomised at 34 North American institutions)
“There was less cognitive deterioration at 3 months after SRS alone (40/63 patients [63.5%]) than when combined with WBRT (44/48 patients [91.7%]”
No source we could reach gives a recovery figure for vision after brain radiotherapy; the published reports of radiation damage to the optic nerve are single cases, some of which improved and some of which did not.
Searched: optic neuropathy with radiation and recovery; cataract with cranial radiotherapy
Treatment of the prostate, rectum, cervix, womb or bladder, with the bowel and bladder in the field.
Sperm production is extremely sensitive to radiation: very small scattered doses recover within a year or two, but above about 1.2 gray the chance of recovery falls, and no dose has been defined above which infertility is certain.
When: return to normal sperm concentration within 12 to 24 months after testicular doses of 0.2 to 0.7 gray
How many: no proportion stated (review of men treated with radiotherapy and chemotherapy for cancer)
“doses between 0.2 and 0.7 Gy caused a transient dose-dependent increase in FSH and reduction in sperm concentration, with a return to normal values within 12-24 months”
Bowel function is at its worst about six months after prostate radiotherapy and then partly recovers, with one exception: blood in the stool becomes more frequent rather than less as the years pass.
When: assessed at 6 and 12 months and annually to 6 years
How many: no proportion stated in the abstract (1,643 men in the ProtecT randomised trial of monitoring, surgery or radiotherapy with hormones)
“Bowel function was worse in the radiotherapy group at 6 months than in the other groups but then recovered somewhat, except for the increasing frequency of bloody stools”
Urinary problems after prostate radiotherapy are mostly a passing phase: flow and night-time waking are worse at six months and back to much the same as the other treatment groups by a year, and leakage is barely affected.
When: worse at 6 months, mostly recovered and similar to other groups after 12 months
How many: no proportion stated in the abstract (1,643 men in the ProtecT randomised trial)
“Urinary voiding and nocturia were worse in the radiotherapy group at 6 months but then mostly recovered and were similar to the other groups after 12 months.”
Erections are at their worst about six months after prostate radiotherapy, improve somewhat after that, and then settle at a level that does not improve further.
When: worst at 6 months, partial recovery, then stable through 6 years of follow-up
How many: no proportion stated in the abstract (1,643 men in the ProtecT randomised trial, radiotherapy given with hormones)
“The negative effect of radiotherapy on sexual function was greatest at 6 months, but sexual function then recovered somewhat and was stable thereafter”
Radiotherapy to the whole body as part of the conditioning before a stem cell transplant.
About one person in five develops a severe lung inflammation in the first weeks after total body irradiation, and giving the dose more slowly roughly halves that, but no source we could reach reports what proportion of lungs recover afterwards.
When: onset between 4 and 73 days after transplant, median 16 days
How many: idiopathic pneumonia syndrome in 42 of 202 patients (21%), and 29% with a dose rate above 15 cGy per minute against 10% at or below it (202 patients with acute leukaemia aged 1 to 57 having total body irradiation conditioning)
Searched: idiopathic pneumonia syndrome with total body irradiation; radiation pneumonitis with fibrosis and irreversible
After total body irradiation and a marrow transplant most people never regain gonadal function; pregnancies do happen but they are the exception and carry a higher risk of miscarriage and early delivery.
When: patients transplanted between 1971 and 1992 and followed into adulthood
How many: 110 of 708 post-pubertal women recovered normal ovarian function and 32 became pregnant; 157 of 618 post-pubertal men recovered testicular function (1,326 post-pubertal and 196 pre-pubertal transplant patients in Seattle)
“Among 708 postpubertal women, 110 recovered normal ovarian function and 32 became pregnant.”
Children given total body irradiation commonly stop growing at the expected rate and most of those who do turn out to be growth hormone deficient; the deficiency does not resolve, but replacement treatment works.
When: growth failure appeared in the first year after irradiation if the brain had also been irradiated, and in the third year if it had not
How many: growth rate fell to -1.36 standard deviation scores by the third year after total body irradiation, against 0.10 before transplant (76 pre-pubertal children, 37 given total body irradiation and 22 given busulfan)
“GH deficiency was shown in the vast majority of children with growth impairment.”
Cataract after total body irradiation does not reverse, but it is the one late effect here that surgery can fix; with single-fraction treatment more than half needed an operation within ten years.
When: no surgery before 2 years, and the longest recorded interval before surgery was 12 years
How many: probability of needing cataract surgery 5% at 2 years, 39% at 5 years and 58% at 10 years (135 of 173 surviving patients who had single-fraction total body irradiation and a marrow transplant at the Royal Marsden, 1977 to 1991)
“The probability of requiring surgery for cataract at 2, 5 and 10 years post TBI was 5%, 39% and 58%, respectively.”
Removing the lymph nodes under the arm in breast cancer, either a few (sentinel) or most of them (clearance).
Numbness in the armpit and inner upper arm is common after a full clearance and is still present in about a third of women a year later; sentinel node biopsy cuts that risk roughly threefold, and sparing the intercostobrachial nerve reduces it further.
When: assessed at 12 months
How many: sensory loss 11% after sentinel node biopsy versus 31% after standard axillary treatment (1031 women randomised in the UK ALMANAC trial)
“at 12 months were 0.37 (95% confidence interval [CI] = 0.23 to 0.60; absolute rates: 5% versus 13%) and 0.37 (95% CI = 0.27 to 0.50; absolute rates: 11% versus 31%), respectively.”
Arm swelling after a full axillary clearance affects about one woman in four, and once it is there it tends to stay: in a randomised trial the extra arm volume was still unchanged five years on.
When: measured at 5 years after surgery
How many: 24.5% after axillary dissection versus 11.9% after axillary radiotherapy (1425 sentinel-node-positive women randomised in the EORTC AMAROS trial)
“ALND was associated with a higher lymphedema rate in updated 5-year analyses (24.5% v 11.9%; P < .001).”
No source we could reach gives a recovery figure for fatigue attributable to axillary surgery itself; the randomised trials of sentinel node biopsy versus clearance measured arm swelling, sensation and arm function, not fatigue.
Searched: fatigue with axillary and breast; fatigue with sentinel lymph node biopsy; ALMANAC; lymphoedema with sentinel and axillary
Removing the prostate, with the nerves that run beside it either spared or taken.
The prostate and seminal vesicles are removed, so ejaculation stops and does not come back; orgasm is still possible but dry, and men who may want children later need to bank sperm before surgery.
How many: 58% of men did not recall being told about anejaculation, and only 7% of those interested in future fertility had banked sperm (364 men aged 50 or under surveyed within three months of radical prostatectomy)
“Fifty-eight percent of men did not recall being told about anejaculation post-RP, 84% were unaware that sperm banking preoperatively was an option”
Leakage is worst straight after surgery and improves over the first year, but it does not settle back to where it started: roughly one man in five still needs pads years later, more than after radiotherapy or monitoring.
When: 7 to 12 years after treatment
How many: 18 to 24% needing pads, against 9 to 11% on active monitoring and 3 to 8% after radiotherapy (1643 men randomised in the ProtecT trial)
“Among those in the prostatectomy group, urinary leakage requiring pads occurred in 18 to 24% of patients over 7 to 12 years, compared with 9 to 11% in the active monitoring group and 3 to 8% in the radiotherapy group.”
Erections recover slowly over the first two years and for many men never return to what they were; in the only randomised comparison, 18 per cent could manage intercourse at seven years, fewer than after radiotherapy or monitoring.
When: partial recovery over 1 to 2 years; measured at 7 years
How many: 18% with erections sufficient for intercourse at 7 years (1643 men randomised in ProtecT; a separate meta-analysis of 22 published nerve-sparing series put overall erectile function recovery at 58%)
“In the prostatectomy group, 18% reported erections sufficient for intercourse at 7 years, compared with 30% in the active monitoring and 27% in the radiotherapy groups; all converged to low levels of potency by year 12.”
Removing the rectum and rejoining the bowel, with or without a temporary or permanent stoma.
Bowel function after an anterior resection improves steadily for about eighteen months and then levels off; a large minority are left with major low anterior resection syndrome for good.
When: improves to 18 months, then stable to 3 years
How many: mean LARS score 29.4 at 3 to 6 months falling to 16.6 at 36 months (701 patients pooled from 8 studies in an individual-patient meta-analysis; in a separate long-term cohort 49% still had major LARS 7 to 16 years after surgery)
“LARS improves by 18 months postoperatively then remains stable for up to 3 years.”
Trouble emptying the bladder affects about one patient in ten after rectal surgery and usually settles within a year; it became permanent only where the pelvic nerves on one side had to be removed.
When: dysfunction that has not improved by 1 year was counted as permanent
How many: 102 of 1017 patients (10.0%) (single-centre series of robotic rectal cancer resections, 2011 to 2021; incidence rose to 65.4% where autonomic nerves were totally resected on at least one side against 28.8% with bilateral preservation)
“Urinary dysfunction was observed in 102 patients (10.0%).”
Erectile and ejaculatory problems are common after rectal surgery even when it is done by keyhole or robotic technique, and around four men in ten still report them a year later.
When: assessed 12 months after surgery
How many: 129 of 300 men (43.0%) with erectile or ejaculatory dysfunction at 12 months (multicentre prospective LANDMARC cohort, 49 Japanese institutions, men with no preoperative dysfunction)
“SD was observed in 129 (43.0%) patients.”
Removing a lobe of the lung, or the whole lung.
Breathing capacity drops sharply after the operation and then claws some of it back: three months after a lobectomy people were at about 84 per cent of their old FEV1, after a whole lung removed about 66 per cent.
When: measured at 1 month and 3 months after surgery
How many: FEV1 79.5% of preoperative at 1 month and 84% at 3 months after lobectomy; 65% and 66% after pneumonectomy (200 patients measured prospectively before surgery, at discharge, 1 month and 3 months)
“One month after lobectomy, FEV(1), Dlco, and Vo(2)peak values were 79.5%, 81.5%, and 96% of preoperative values and recovered up to 84%, 88.5%, and 97% after 3 months, respectively.”
Chest wall pain from an open thoracotomy persists past six months in roughly one person in five, and the choice of nerve block at the time of surgery does not change that.
When: chronic pain assessed at 6 months after randomisation
How many: 59 of 272 (22%) with paravertebral blockade and 47 of 292 (16%) with thoracic epidural blockade (770 adults randomised to thoracotomy analgesia in 15 UK centres (TOPIC2))
“At 6 months, 59 (22%) of 272 participants in the paravertebral blockade group and 47 (16%) of 292 in the thoracic epidural blockade group developed chronic pain”
Fatigue peaks in the first month after lung surgery and eases for most people, but about one in five is still clinically tired a year or more later.
When: peaks within 1 month; still measured beyond 12 months
How many: pooled prevalence of clinically significant fatigue 19.6% within 1 month and 17.7% at 1 year or more (2618 participants across 11 studies, 5 contributing to the meta-analysis)
“Across all time points, the pooled prevalence was 18.6% (95% CI: 14.8-23.2%).”
Removing the stomach or the gullet and rebuilding the way food travels.
Bone density falls after gastrectomy and keeps falling for years rather than recovering; about one person in five had a spinal fracture within five years.
When: bone density and fractures assessed at 1, 3 and 5 years
How many: vertebral fractures in 19.2% at 5 years (485 patients after curative gastrectomy for gastric cancer at multiple centres, 2005 to 2018)
“The overall incidence of VFs at 5 years was 19.2 %, with a significantly greater BMD reduction observed in the VF group.”
Weight falls after the stomach is removed and most of it does not come back: a year on, people who lost the whole stomach were about 15 per cent lighter, those who kept part of it about 6 per cent.
When: measured at 1 year after gastrectomy
How many: 15.11% body weight loss at one year after total gastrectomy and 5.96% after distal gastrectomy (control arms of the KSES002 randomised trial, 17 and 32 patients respectively)
“9.66 ± 5.98% [95% confidence interval, CI: 6.77-12.54] vs 15.11 ± 6.78% [95% CI: 11.63-18.60]”
Taking out both ovaries, for cancer or to prevent it in someone at high inherited risk.
Both ovaries are removed, so periods and natural fertility end at once and do not return; the literature treats this as immediate and permanent rather than as something that recovers.
“Premenopausal RRSO leads to immediate menopause, which has been associated with an acute phase of rapid bone loss.”
Removing both ovaries brings the menopause on within weeks and it is permanent; hot flushes peak by three months and are no better two years later, and hormone therapy softens them without clearing them.
When: symptoms peak by 3 months and are unchanged at 24 months
How many: hot flushes in 59% at 24 months, up from 6% before surgery; 54% of hormone therapy users and 88% of non-users still had them (104 premenopausal women having risk-reducing surgery, with 102 age-matched comparators (WHAM study))
“At 24 months after RRSO the prevalence of vasomotor symptoms had increased from 6 % at baseline to 59 % and night sweats from 21 % to 39 %.”
Bone thins quickly after surgical menopause and the loss does not reverse: eighteen years on, women who had their ovaries removed before the menopause still had lower bone density than those who had it later.
When: median 18.1 years after surgery
How many: twice the chance of a bone density Z-score of -1.0 or lower in the lumbar spine (relative risk 2.35) (493 women with premenopausal surgery compared with 228 who had it postmenopausally)
“Eighteen years after premenopausal RRSO, women had lower bone mineral density compared with women who underwent a postmenopausal RRSO.”
Women whose ovaries were removed before the menopause and before age 46 were about twice as likely to have mild cognitive impairment roughly thirty years later, and taking oestrogen afterwards did not remove the difference.
When: median 30 years between surgery and cognitive testing
How many: adjusted odds ratio 2.21 (95% CI 1.41-3.45) for mild cognitive impairment (2732 women aged 50 to 89 in the Mayo Clinic Study of Aging, 283 with mild cognitive impairment)
“Bilateral oophorectomy before menopause and before age 46 years was associated with clinically diagnosed MCI (adjusted odds ratio [aOR], 2.21; 95% CI, 1.41-3.45; P < .001) compared with no bilateral oophorectomy.”
Desire, arousal, lubrication and comfort all decline after the ovaries are removed and do not return to where they were; hormone therapy helps some women but does not undo the change.
When: measured from 12 months to about 3.5 years after surgery
How many: pooled standardised mean difference -0.63 (95% CI -0.82 to -0.44) in sexual function; 15 of 21 studies reported a negative effect (meta-analysis of 3201 women at high genetic risk of ovarian cancer)
“Sexual function declines post RRBSO, independent of menopausal status.”
Removing the lymph nodes of the neck in head and neck cancer, around the nerve that lifts the shoulder.
The shoulder is usually weak and stiff after a neck dissection even when the accessory nerve is left intact; most of the movement comes back by six months, but a sizeable minority are still short of a full lift overhead.
When: most recovery between 1 and 6 months, assessed to 12 months
How many: 41.5% still unable to abduct the shoulder to 150 degrees at 6 months, down from 82.4% at 1 month (66 patients, 85 neck dissection sides, single institution, 2015 to 2017)
“The proportion of patients who were unable to abduct their shoulders by 150° or more was significantly lower at 6 months postoperatively (41.5%) compared with 1 month postoperatively (82.4%, p < 0.0001).”
Swelling of the face and neck is common when neck dissection is followed by radiotherapy, and about half of those patients still had it a year after treatment.
When: assessed 1 year after treatment
How many: 44 of 84 patients had lymphoedema one year after treatment (single tertiary centre cohort of treatment-naive patients who had cervical lymphadenectomy and completed adjuvant radiation)
“In total, 84 patients were included, 44 had lymphedema 1 year after treatment.”
Nearly everything written about immunotherapy side effects says they are manageable and reversible, and for the liver, the bowel, the lungs and the skin that is broadly true. The hormone glands are the exception, and the people who follow patients after treatment ends have measured it: in 387 people given a year of anti-PD-1 after melanoma surgery, 83 per cent of the hormone problems were still there three months after the drug stopped, while colitis persisted in 6 of 44 cases and most of those cleared in the end. A gland that has been destroyed does not grow back. What follows is what each gland does, and what the follow-up cohorts found.
| Gland | What happens | Does it come back | What the source says |
|---|---|---|---|
| Pituitary (hypophysitis) | Inflammation of the gland that instructs the others. It typically appears about three months in, and the first sign is often headache or a flat exhaustion that is put down to the cancer. | Does not usually come back none of 22 recovered the adrenal axis; the thyroid axis recovered in 33% and the gonadal axis in 67% (22 patients with checkpoint-induced hypophysitis at a tertiary endocrine and immunotherapy clinic) | “None recovered SAI during follow-up, whilst recovery of SH and SHG was noted in 33% and 67%, respectively.” Checkpoint inhibitor hypophysitis in a tertiary centre, Clinical Endocrinology 2026 |
| Thyroid (thyroiditis) | A brief overactive phase, often missed, followed by an underactive gland. It is the commonest hormonal effect of these drugs and the easiest to replace. | Does not usually come back 2 of 103 regained their own thyroid function; 64 reached normal levels on levothyroxine (103 patients with checkpoint-associated thyroiditis at an academic centre) | “Sixty-six of the 103 patients achieved euthyroid state; 2 with intrinsic thyroid gland function recovery and 64 on LT4.” Levothyroxine dosing in checkpoint-associated hypothyroidism, Thyroid 2022 |
| Adrenal glands | Loss of cortisol, either from the pituitary above or from the adrenal glands themselves. Untreated it can be fatal in an illness or an operation, which is why it is the one worth knowing about before it happens. | Does not usually come back of 93 people whose immune side effects were still present at last follow-up, 16 were on replacement steroids for hypophysitis or adrenal insufficiency (318 patients given adjuvant anti-PD-1 for resected melanoma at six centres in the United States and Australia, median follow-up 1,057 days) | “24 (25.8%) were using therapeutic systemic steroids (16 [67%] of whom were on replacement steroids for hypophysitis (8 [50.0%]) and adrenal insufficiency (8 [50.0%])” Extended follow-up of chronic immune-related adverse events, JAMA Network Open 2023 |
| Insulin-making cells of the pancreas | A sudden diabetes, often presenting as a diabetic emergency rather than as a gradual rise in blood sugar. The cells that make insulin are destroyed, not suppressed. | Does not usually come back all 34 remained insulin-dependent at the end of follow-up (CANDIED, five Canadian cancer centres, patients on anti-PD-1 or anti-PD-L1 based therapy, onset at a median 2.4 months) | “All patients remained insulin-dependent at the end of follow-up.” CANDIED, checkpoint-induced insulin-dependent diabetes, Cancers 2021 |
| For contrast: the bowel | Colitis is the immune side effect people are warned about most, and it is the one that behaves the way the consent conversation describes: it settles, and the few cases that drag on mostly clear in the end. | Usually comes back colitis became chronic in 6 of 44 cases, and 4 of those 6 later resolved, against 73 of 88 hormone problems becoming chronic (387 patients given adjuvant anti-PD-1 for stage III to IV melanoma at eight academic centres) | “Endocrinopathies (73 of 88; 83.0%), arthritis (22 of 45; 48.9%), xerostomia (9 of 17; 52.9%), neurotoxicities (11 of 15; 73.3%), and ocular events (5 of 8; 62.5%) were particularly likely to become chronic.” Chronic immune-related adverse events after adjuvant anti-PD-1, JAMA Oncology 2021 |
None of this is an argument against checkpoint inhibitors, which cure people who would once have died. It is an argument for being told at the start, for a hormone blood test at the first hint of exhaustion, nausea or dizziness, and for nobody being left to work out years later that the tiredness they have had since treatment is an untreated hormone deficiency. Replacement is cheap, lifelong and effective: the harm is in the delay, not in the diagnosis.
Where a published threshold exists, the number is here rather than in a sentence, because it is the number to ask your team about: how much of this drug have I had in total, and how much is the organ at risk going to receive. Each row is in the source's own terms.
| Treatment | What it affects | The published threshold | Measured in |
|---|---|---|---|
| Anthracyclines | Heart muscle and circulation | the probability of cardiomyopathy is estimated at 1 to 2% at a cumulative doxorubicin dose of 300 mg/m2, 3 to 5% at 400 mg/m2, 5 to 8% at 450 mg/m2 and 6 to 20% at 500 mg/m2, given every 3 weeks “estimated to be 1 to 2% at a total cumulative dose of 300 mg/m2 of doxorubicin, 3 to 5% at a dose of 400 mg/m2, 5 to 8% at a dose of 450 mg/m2, and 6 to 20% at a dose of 500 mg/m2” | the US prescribing information for doxorubicin hydrochloride injection, which also states that cumulative doses above 550 mg/m2 carry an increased risk FDA label, doxorubicin hydrochloride injection (Hikma), warnings and precautions, cardiomyopathy |
| Anthracyclines | Heart muscle and circulation | an estimated cumulative 26% would develop doxorubicin-related congestive heart failure at 550 mg/m2, against the 7% at the same dose reported by the earlier large study; the two sources disagree and both are given here “Analysis indicated that an estimated cumulative 26% of patients would experience doxorubicin-related CHF at a cumulative dose of 550 mg/m(2).” | 630 patients in the doxorubicin-plus-placebo arms of three phase 3 trials, two in breast carcinoma and one in small cell lung carcinoma; 32 of 630 developed heart failure Congestive heart failure in patients treated with doxorubicin: a retrospective analysis of three trials, Cancer 2003 |
| Cisplatin | Hearing and tinnitus | hearing worsened by 8.72 per 100 mg/m2 of cumulative cisplatin on the study's measure, and the effect strengthened as kidney function fell “audiometrically-assessed hearing was significantly associated with cumulative cisplatin dose (β = 8.72 per 100 mg/m2, p = 0.0004), reduced eGFR (β = 3.90 per 20 mL/min/1.73 m2, p = 0.043)” | 1,422 cisplatin-treated testicular cancer survivors enrolled between 2012 and 2018 at eight academic cancer centres in the USA, Canada and the UK, hearing measured from 0.25 to 12 kHz The Platinum Study, EClinicalMedicine 2026 |
| Cisplatin | Hearing and tinnitus | hearing loss worsened with rising cumulative dose across a range of 200 to 800 mg/m2, median 400 mg/m2, and 18% of the men had severe to profound hearing loss “Increasing cumulative cisplatin dose (median, 400 mg/m(2); range, 200 to 800 mg/m(2)) was significantly related to hearing loss at 4, 6, 8, 10, and 12 kHz” | 488 North American male germ cell tumour survivors, audiometry from 0.25 to 12 kHz with middle ear function and tinnitus Comprehensive audiometric analysis of hearing impairment and tinnitus after cisplatin-based chemotherapy, Journal of Clinical Oncology 2016 |
| Bleomycin | Lungs | more than 400 units total dose; pulmonary adverse reactions occur in approximately 10% of treated patients and approximately 1% have died of pulmonary fibrosis “Pulmonary toxicity is both dose and age related, being more common in patients over 70 years of age and in those receiving over 400 units total dose. This toxicity, however, is unpredictable” | the US prescribing information for bleomycin for injection, which stresses that the toxicity is unpredictable and has been seen in young patients on low doses FDA label, bleomycin for injection (Fresenius Kabi), adverse reactions, pulmonary |
| Bleomycin | Lungs | a cumulative bleomycin dose above 300,000 IU raised the risk of lung toxicity 3.5-fold; age over 40 and stage IV disease were the other independent risk factors “stage IV disease at presentation (HR 2.6) and cumulative dose of bleomycin >300,000 IU (HR 3.5).” | 835 men treated with bleomycin-containing regimens for germ-cell tumours at the Royal Marsden, 1982 to 1999 Predicting the risk of bleomycin lung toxicity in patients with germ-cell tumours, Annals of Oncology 2003 |
| Oxaliplatin | Nerves in the hands and feet | no cumulative dose in mg/m2 is published; the label gives the median time to grade 3 sensory neuropathy as 9 cycles in adjuvant treatment and 6 cycles in previously treated advanced disease “For grade 3 peripheral sensory neuropathy, the median time to onset was 9 cycles for adjuvant treatment and 6 cycles for previously treated advanced colorectal cancer.” | patients receiving oxaliplatin with fluorouracil and leucovorin, as reported in the approved label, where 80% of those reaching grade 3 had progressed from a prior grade 1 or 2 reaction FDA label, oxaliplatin injection (Hospira), warnings and precautions, acute and delayed neuropathy |
| Cyclophosphamide | Fertility | a cyclophosphamide equivalent dose below 4,000 mg/m2 rarely impaired sperm production: 31 of 35 men below that dose had normal counts “31 (89%) of 35 participants who received CED less than 4000 mg/m(2) were normospermic.” | 214 adult male survivors of childhood cancer given alkylating agents but no radiotherapy, St Jude Lifetime Cohort, a median 21 years after diagnosis Cumulative alkylating agent exposure and semen parameters, Lancet Oncology 2014 |
| Cyclophosphamide | Fertility | a cyclophosphamide equivalent dose of 7,200 mg/m2 best separated men with no or few sperm from men with normal counts “Risk for azoospermia and oligospermia among those not treated with a platinating agent was best distinguished from risk for normospermia using a CED cutoff of 7,200 mg/m2 on the basis of the Youden index.” | unirradiated male childhood cancer survivors exposed to alkylating agents, St Jude Lifetime Cohort, of whom 22.1% were azoospermic and 26.7% oligospermic Cyclophosphamide equivalent dose and semen quality, Fertility and Sterility 2026 |
| Cyclophosphamide | Hormone glands | a cyclophosphamide equivalent dose of 7.5 g/m2 or more independently predicted treatment-related amenorrhoea, odds ratio 4.56 (95% CI 1.4 to 14) “On multivariable analysis, independent predictors of TRA included postpubertal status at diagnosis (OR: 20.45; CI: 4-101.5), solid tumor diagnosis (OR: 5.98; CI: 1.7-8), and CED of ≥7.5 g/m2 (OR: 4.56; CI: 1.4-14).” | 186 female childhood cancer survivors, mean age 21, mean follow-up 10 years, mean cyclophosphamide equivalent dose 5.1 g/m2, of whom 24% had amenorrhoea with raised gonadotrophins Treatment-related amenorrhoea in childhood cancer survivors, Journal of Pediatric Hematology/Oncology 2026 |
| Cyclophosphamide | Bladder and urinary control | a cumulative dose above 36 g carries a markedly raised risk of bladder cancer, which stays high for years after the drug is stopped “The risk of bladder cancer is especially higher in long-term exposure and with cumulative doses above 36 g. The risk remains high for years after drug discontinuation.” | patients with systemic autoimmune disease and vasculitis treated with cyclophosphamide, systematic review of 18 studies Brazilian Society of Rheumatology position statement on cyclophosphamide, Advances in Rheumatology 2024 |
| Vinca alkaloids | Nerves in the hands and feet | a cumulative vincristine dose above 53 mg was associated with persisting clinically significant neuropathy, odds ratio 5.29 (95% CI 1.41 to 19.85) “Clinically significant peripheral neuropathy (PN) was reported in 35.1% before maintenance and persisted in 37% at last follow-up, associated with age ≥30 years (OR 6.78, 95% CI 2.07-22.2, p = 0.002) and cumulative vincristine >53 mg” | 96 adults treated for acute lymphoblastic leukaemia between 2014 and 2023 at a Mexican tertiary centre, median age 29.5 Vincristine neuropathy in adult ALL, Leukemia and Lymphoma 2026 |
| Other alkylating drugs | Lungs | a cumulative carmustine dose above 1,400 mg/m2 carries a significantly higher risk of lung toxicity, and delayed fibrosis has been reported years later, particularly in people treated in childhood “Delayed pulmonary toxicity can occur years after treatment, and can result in death, particularly in patients treated in childhood” | the US prescribing information for carmustine for injection Carmustine for injection prescribing information, DailyMed |
| Radiotherapy to the head and neck | Mouth, saliva, taste and swallowing | mean dose under approximately 20 Gy to at least one parotid gland, or under approximately 25 Gy to both, to avoid severe dry mouth, defined as long-term salivary function below a quarter of baseline “if at least one parotid gland is spared to a mean dose of less than approximately 20 Gy or if both glands are spared to less than approximately 25 Gy (mean dose)” | QUANTEC review of published parotid dose, volume and salivary toxicity series QUANTEC parotid, Int J Radiat Oncol Biol Phys 2010 |
| Radiotherapy to the chest | Lungs | no threshold dose or volume exists below which pneumonitis does not occur; the QUANTEC recommendation is expressed as a mean lung dose of 20 to 23 Gy “The rate of symptomatic pneumonitis is related to many dosimetric parameters, and there are no evident threshold "tolerance dose-volume" levels.” | QUANTEC review of three-dimensional lung dose, volume and outcome data QUANTEC lung, Int J Radiat Oncol Biol Phys 2010 |
| Radiotherapy to the chest | Heart muscle and circulation | no threshold; the rate of major coronary events rises 7.4% for every gray of mean heart dose, and the women studied received an average mean heart dose of 4.9 Gy “The overall average of the mean doses to the whole heart was 4.9 Gy (range, 0.03 to 27.72).” | 2,168 women irradiated for breast cancer in Sweden and Denmark between 1958 and 2001, with older techniques than are used now Risk of ischaemic heart disease after radiotherapy for breast cancer, New England Journal of Medicine 2013 |
| Radiotherapy to the chest | Nerves in the hands and feet | spinal cord injury risk under 1% at 54 Gy and under 10% at 61 Gy in 1.8 to 2 Gy fractions to the full thickness of the cord “the estimated risk of myelopathy is <1% and <10% at 54 Gy and 61 Gy, respectively, with a calculated strong dependence on dose/fraction (alpha/beta = 0.87 Gy.)” | QUANTEC review of human myelopathy dose and volume data with supporting preclinical data QUANTEC spinal cord, Int J Radiat Oncol Biol Phys 2010 |
| Radiotherapy to the pelvis | Bowel function | the volume of rectum receiving 60 Gy or more drives the risk of moderate or worse rectal toxicity “The volume of rectum receiving >or=60 Gy is consistently associated with the risk of Grade >or=2 rectal toxicity or rectal bleeding.” | QUANTEC review drawing mainly on three-dimensional dose-escalation studies in early prostate cancer QUANTEC rectum, Int J Radiat Oncol Biol Phys 2010 |
| Radiotherapy to the pelvis | Fertility | the fractionated ovarian dose at which the ovaries fail immediately in 97.5% of patients is 20.3 Gy at birth, 18.4 Gy at age 10, 16.5 Gy at age 20 and 14.3 Gy at age 30 “ESD at birth is 20.3 Gy; at 10 years 18.4 Gy, at 20 years 16.5 Gy, and at 30 years 14.3 Gy.” | a model built from measured human egg radiosensitivity and planned ovarian doses in women treated for cancer Predicting age of ovarian failure after radiation to a field that includes the ovaries, Int J Radiat Oncol Biol Phys 2005 |
| Radiotherapy to the pelvis | Fertility | testicular doses below 0.2 Gy had no measurable effect; 0.2 to 0.7 Gy caused temporary suppression recovering in 12 to 24 months; 1.2 Gy and above reduced the chance of recovery, and no dose has been defined above which permanent azoospermia is inevitable “No radiation dose threshold has been defined above which permanent azoospermia is inevitable; however, doses of 1.2 Gy and above are likely to be associated with a reduced risk of recovery of spermatogenesis” | review of men treated with radiotherapy and chemotherapy for cancer Spermatogenesis after cancer treatment, JNCI Monographs 2005 |
| Radiotherapy to the brain | Hormone glands | median biologically effective dose to the hypothalamus and pituitary of 77.5 Gy in children who developed growth hormone deficiency, against 54.5 Gy in those who did not “Fifty-eight patients (80%) had GHD and they had received a median BED of 77.5 Gy to the HP region, whereas the median BED was 54.5 Gy for 15 patients without GHD (P = 0.002).” | 91 children irradiated for a brain tumour, median age 8.7 years at radiotherapy, median follow-up 15 years Cranial radiotherapy of childhood brain tumours and growth hormone deficiency, Clinical Endocrinology 2000 |
| Radiotherapy to the brain | Thinking and memory | cognitive dysfunction in children is largely seen at whole-brain doses of 18 Gy or more, and QUANTEC found no substantial evidence that radiotherapy causes irreversible cognitive decline in adults within 4 years “Cognitive dysfunction in children is largely seen for whole brain doses of >or=18 Gy. No substantial evidence has shown that RT induces irreversible cognitive decline in adults within 4 years of RT.” | QUANTEC review of published radiotherapy-induced brain injury data QUANTEC brain, Int J Radiat Oncol Biol Phys 2010 |
| Radiotherapy to the head and neck | Hearing and tinnitus | QUANTEC could not define a threshold cochlear dose for sensorineural hearing loss; a later prospective cohort found significantly more loss above 45 Gy mean cochlear dose and significantly less below 35 Gy “Based on the data, a specific threshold dose to cochlea for sensorineural hearing loss cannot be determined; therefore, dose-prescription limits are suggested.” | QUANTEC literature review, with the 45 Gy and 35 Gy figures from 130 patients with head and neck cancer QUANTEC auditory, Int J Radiat Oncol Biol Phys 2010 |
15.6 per cent of the grid is filled. Part of the rest is pairs that do not arise, and part is a real hole in the literature: effects are counted at the end of a trial and rarely followed until they resolve or do not, so the question a patient asks is often the one nobody measured.
Background: CTCAE toxicity grading (grade 3-4 adverse events), De-escalation, escalation and response-adapted therapy, Immune-related adverse events (irAEs), Quality of life, Toxicity grade. Also on OnCo: Side effects by symptom · Checkpoint side effects by organ · Side effect rates across a drug class · Survivorship planner.
Related: the survivorship planner, which gives the screening test and the interval for each late effect, is the next page after this one · recovery and rejuvenation · hair loss and regrowth · side effect rates across a drug class · checkpoint side effects by organ. Figures are quoted from the cohort or trial named beside them and are not adjusted for differences between populations; OnCo is orientation, not medical advice.