The first 60 days: HR-positive / HER2-negative breast cancer
HR-positive breast cancer is the most common breast cancer, driven by oestrogen. It was treated for years with hormone-blocking pills, now joined by CDK4/6 inhibitors, PI3K-pathway drugs, degraders, and ADCs. Below, week by week, is what OnCo's record of HR-positive / HER2-negative breast cancer says about the first two months: the order is typical, the timing is yours to ask about. Sections appear only where the record has something to say. Orientation, not medical advice.
Weeks 1 to 2
What happens now
Staging tests establish exactly what and where the cancer is. Everything else follows from the answers.
Mammography ± tomosynthesis; supplemental MRI for dense breasts or high risk; core biopsy with ER/PR/HER2/Ki-67; AI-assisted reading being deployed.
From the recorded treatment journey
- Core biopsy with ER, PR, HER2 and Ki-67; mammography and ultrasound, MRI when needed.
- A 21-gene recurrence score (or similar) on the tumour: in TAILORx, women over 50 with node-negative disease and a score of 11-25 gained nothing from chemotherapy.
Biomarkers your report may list
ER/PRHER2 IHC 0/1+/2+ (low, ultralow)Ki-67Oncotype DX / MammaPrint / ProsignaPIK3CA/AKT1/PTENESR1 (ctDNA)gBRCAER and PR by IHC (≥1%; 1-10% 'ER-low' behaves like TNBC)HER2 IHC 0/1+/2+ with the low and ultralow categories for T-DXd eligibilityKi-67 (≥20% defines high risk for adjuvant abemaciclib, monarchE cohort 2)Oncotype DX recurrence score, MammaPrint, Prosigna, Breast Cancer Index (late recurrence, extended ET)PIK3CA, AKT1, PTEN alterations (tissue or ctDNA) for PI3K/AKT-pathway drugsESR1 mutation by ctDNA (serial monitoring endorsed by SERENA-6)gBRCA1/2 (olaparib, OlympiA)Menopausal status and oestradiol (for AI eligibility, OFS adequacy)Bone density (AI-induced loss)CDK4/6 resistance markers under study: RB1 loss, CCNE1, FGFR1 amplification
Ask which of these were tested and what the results were; see the report reader for what each value means.
Tests and imaging linked to this cancer
How it is staged
These specialties appear in the standard of care for this cancer. In most centres they meet weekly as a tumour board to agree each plan; you can ask when yours was discussed and what was decided.
- PathologistNamed in the standard of care for: Early stage, Metastatic second line, Screening and diagnosis, Early stage, deciding on chemotherapy and 2 more.
- RadiologistNamed in the standard of care for: Screening and diagnosis.
- SurgeonNamed in the standard of care for: Early stage.
- Medical oncologistNamed in the standard of care for: Early stage, Metastatic first line, Metastatic second line, Endocrine-resistant and 10 more.
- Clinical oncologist (radiotherapy)Named in the standard of care for: Early stage.
- Palliative and supportive care teamNamed in the standard of care for: Metastatic, chemotherapy and later lines, Bone-predominant disease and survivorship.
A second opinion from a centre that treats many similar cases is normal, not rude; the standard of care tells you what to compare it against.
Each row is a setting from the standard of care, in the order it usually arises. Not all will apply to you; your stage and biomarkers decide which do. The guideline grade, where recorded, says how strong the evidence is.
- 1.Early stageNCCN category Category 1, preferred: adjuvant abemaciclib (monarchE) and ribociclib (NATALEE) in high-risk disease, ESMO-MCBS A (monarchE); A (NATALEE), NCCN Guidelines: Breast Cancer
Surgery, radiation, endocrine therapy 5-10 years; chemotherapy if genomic risk high; abemaciclib or ribociclib adjuvant for high-risk.
Genomic assay (Oncotype DX RS ≤25 node-negative or postmenopausal 1-3 nodes; MammaPrint low risk) → endocrine therapy alone; premenopausal RS 16-25 or high clinical risk → chemotherapy or OFS-based escalation.
Postmenopausal: aromatase inhibitor 5-10 years (or tamoxifen → AI switch). Premenopausal: tamoxifen 5-10 years; add OFS (+ AI or tamoxifen) for higher-risk or chemotherapy-treated women (SOFT/TEXT).
Extended AI to 10 years for higher-risk (MA.17R, NSABP B-42); adjuvant giredestrant positive in lidERA (2025, not yet approved); CAMBRIA (camizestrant) and EMBER-4 (imlunestrant) ongoing.
Abemaciclib 2 years for node-positive high-risk (monarchE); ribociclib 3 years for stage II-III including node-negative high-risk (NATALEE). Palbociclib not effective (PALLAS/PENELOPE-B). Olaparib 1 year if gBRCA (OlympiA).
- 6.Metastatic first lineESMO-MCBS 4-5 (MONALEESA-2, -3, -7); 2 (PALOMA-2); 2 (MONARCH 3), NCCN Guidelines: Breast Cancer
CDK4/6 inhibitor + aromatase inhibitor or fulvestrant.
CDK4/6 inhibitor + aromatase inhibitor (or fulvestrant): ribociclib or abemaciclib preferred where OS data are valued; palbociclib acceptable. Premenopausal: add OFS. For relapse on/within 12 months of adjuvant ET with PIK3CA mutation: inavolisib + palbociclib + fulvestrant (INAVO120).
- 8.Metastatic, molecular progression on first lineNCCN category Pending inclusion (approval Sep 2026)
Serial ctDNA; on emergent ESR1 mutation before radiographic progression, switch AI → camizestrant and continue the CDK4/6 inhibitor (SERENA-6; accelerated approval 4 Sep 2026).
- 9.Metastatic second lineESMO-MCBS 3 (CAPItello-291); 3 (INAVO120); 3 (EMERALD); 2 (SOLAR-1); 4 (OlympiAD, gBRCA), NCCN Guidelines: Breast Cancer
Genotype-directed: capivasertib, inavolisib, alpelisib, everolimus; elacestrant/vepdegestrant if ESR1-mutant; gedatolisib.
- 10.Endocrine-resistantESMO-MCBS 4 (DESTINY-Breast04); 3 (DESTINY-Breast06); 4 (TROPiCS-02); 3 (TROPION-Breast01), NCCN Guidelines: Breast Cancer
T-DXd (HER2-low/ultralow) before chemotherapy; sacituzumab govitecan or Dato-DXd after chemotherapy.
ESR1-mutant: elacestrant, imlunestrant (± abemaciclib), or vepdegestrant. PIK3CA/AKT1/PTEN: capivasertib + fulvestrant; alpelisib + fulvestrant. Any genotype after CDK4/6: gedatolisib + palbociclib + fulvestrant (PIK3CA-wild-type, 2026); everolimus + exemestane or giredestrant (filed); abemaciclib switch (postMONARCH, modest).
- 12.Metastatic, endocrine-resistant: ADC before chemotherapyNCCN category 1 (T-DXd HER2-low), ESMO-MCBS 4 (DESTINY-Breast04)
HER2-low or ultralow (~60%): T-DXd (DESTINY-Breast06 chemotherapy-naive; DESTINY-Breast04 after chemotherapy). HER2-zero: sacituzumab govitecan or Dato-DXd after chemotherapy (TROPiCS-02, TROPION-Breast01).
Sequential single-agent chemotherapy (capecitabine, taxanes, eribulin, vinorelbine); olaparib/talazoparib if gBRCA; clinical trials; supportive and palliative care integrated early.
Bisphosphonate or denosumab for bone metastases and AI-induced bone loss; adjuvant bisphosphonates in postmenopausal women; exercise, cardio-oncology, and adherence support.
Decision points in the recorded journey, Stage I-II (early)
- Does the genomic score and stage justify chemotherapy?
- Is the recurrence risk high enough for a CDK4/6 inhibitor?
Generated from this cancer's standard of care, biomarkers and open problems. Take the group that matches where you are. To tick, add your own and print, open the one-page appointment sheet.
Newly diagnosed
- What is my exact diagnosis, stage, and grade, and which tests established them?Everything else follows from an accurate stage and subtype.
- Which biomarkers have been tested on my tumour (for example ER/PR, HER2 IHC 0/1+/2+, Ki-67, Oncotype DX / MammaPrint / Prosigna, PIK3CA/AKT1/PTEN), and what were the results?These results decide eligibility for targeted therapy, immunotherapy, and trials.
- Which subtype is my cancer, and does that change the recommended treatment?Recognised subtypes for this cancer include Luminal A, Luminal B, HER2-low.
- Is germline (inherited) genetic testing recommended for me or my family?Inherited variants can change treatment and matter for relatives.
Early stage
- For my situation (early stage), which of the standard options do you recommend and why?Guideline options include: Surgery, radiation, endocrine therapy 5-10 years; chemotherapy if genomic risk high; abemaciclib or ribociclib adjuvant for high-risk.
- Am I a candidate for Oncotype DX, Abemaciclib, Ribociclib, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
- How do the results of monarchE and NATALEE apply to someone like me?Trial populations differ from individual patients; ask how closely you match.
Metastatic first line
- For my situation (metastatic first line), which of the standard options do you recommend and why?Guideline options include: CDK4/6 inhibitor + aromatase inhibitor or fulvestrant.
- Am I a candidate for Palbociclib, Ribociclib, Abemaciclib, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
Metastatic second line
- For my situation (metastatic second line), which of the standard options do you recommend and why?Guideline options include: Genotype-directed: capivasertib, inavolisib, alpelisib, everolimus; elacestrant/vepdegestrant if ESR1-mutant; gedatolisib.
- Am I a candidate for Capivasertib, Inavolisib, Elacestrant or related drugs, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
Endocrine-resistant
- For my situation (endocrine-resistant), which of the standard options do you recommend and why?Guideline options include: T-DXd (HER2-low/ultralow) before chemotherapy; sacituzumab govitecan or Dato-DXd after chemotherapy.
- Am I a candidate for Trastuzumab deruxtecan, Sacituzumab govitecan, Datopotamab deruxtecan, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
- How do the results of DESTINY-Breast06 apply to someone like me?Trial populations differ from individual patients; ask how closely you match.
Screening and diagnosis
- For my situation (screening and diagnosis), which of the standard options do you recommend and why?Guideline options include: Mammography ± tomosynthesis; supplemental MRI for dense breasts or high risk; core biopsy with ER/PR/HER2/Ki-67; AI-assisted reading being deployed.
Early stage, deciding on chemotherapy
- For my situation (early stage, deciding on chemotherapy), which of the standard options do you recommend and why?Guideline options include: Genomic assay (Oncotype DX RS ≤25 node-negative or postmenopausal 1-3 nodes; MammaPrint low risk) → endocrine therapy alone; premenopausal RS 16-25 or high clinical risk → chemotherapy or OFS-based escalation.
- Am I a candidate for Oncotype DX, MammaPrint (70-gene signature), and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
- How do the results of TAILORx and RxPONDER (SWOG S1007) apply to someone like me?Trial populations differ from individual patients; ask how closely you match.
Early stage, adjuvant endocrine therapy
- For my situation (early stage, adjuvant endocrine therapy), which of the standard options do you recommend and why?Guideline options include: Postmenopausal: aromatase inhibitor 5-10 years (or tamoxifen → AI switch). Premenopausal: tamoxifen 5-10 years; add OFS (+ AI or tamoxifen) for higher-risk or chemotherapy-treated women (SOFT/TEXT).
- Am I a candidate for Letrozole (and other aromatase inhibitors), Tamoxifen, Goserelin / leuprolide (ovarian function suppression), and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
- How do the results of SOFT & TEXT apply to someone like me?Trial populations differ from individual patients; ask how closely you match.
Early stage, high risk: adjuvant CDK4/6
- For my situation (early stage, high risk: adjuvant cdk4/6), which of the standard options do you recommend and why?Guideline options include: Abemaciclib 2 years for node-positive high-risk (monarchE); ribociclib 3 years for stage II-III including node-negative high-risk (NATALEE). Palbociclib not effective (PALLAS/PENELOPE-B). Olaparib 1 year if gBRCA (OlympiA).
- Am I a candidate for Abemaciclib, Ribociclib, Olaparib, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
- How do the results of monarchE and NATALEE apply to someone like me?Trial populations differ from individual patients; ask how closely you match.
Early stage, extended and adjuvant SERD (emerging)
- For my situation (early stage, extended and adjuvant serd (emerging)), which of the standard options do you recommend and why?Guideline options include: Extended AI to 10 years for higher-risk (MA.17R, NSABP B-42); adjuvant giredestrant positive in lidERA (2025, not yet approved); CAMBRIA (camizestrant) and EMBER-4 (imlunestrant) ongoing.
- Am I a candidate for Giredestrant, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
- How do the results of lidERA and CAMBRIA-1 & CAMBRIA-2 apply to someone like me?Trial populations differ from individual patients; ask how closely you match.
Metastatic, first line
- For my situation (metastatic, first line), which of the standard options do you recommend and why?Guideline options include: CDK4/6 inhibitor + aromatase inhibitor (or fulvestrant): ribociclib or abemaciclib preferred where OS data are valued; palbociclib acceptable. Premenopausal: add OFS. For relapse on/within 12 months of adjuvant ET with PIK3CA mutation: inavolisib + palbociclib + fulvestrant (INAVO120).
- Am I a candidate for Ribociclib, Abemaciclib, Palbociclib or related drugs, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
- How do the results of MONALEESA-2 and MONARCH 3 apply to someone like me?Trial populations differ from individual patients; ask how closely you match.
Metastatic, molecular progression on first line
- For my situation (metastatic, molecular progression on first line), which of the standard options do you recommend and why?Guideline options include: Serial ctDNA; on emergent ESR1 mutation before radiographic progression, switch AI → camizestrant and continue the CDK4/6 inhibitor (SERENA-6; accelerated approval 4 Sep 2026).
- Am I a candidate for Camizestrant, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
- How do the results of SERENA-6 apply to someone like me?Trial populations differ from individual patients; ask how closely you match.
Metastatic, second line by genotype
- For my situation (metastatic, second line by genotype), which of the standard options do you recommend and why?Guideline options include: ESR1-mutant: elacestrant, imlunestrant (± abemaciclib), or vepdegestrant. PIK3CA/AKT1/PTEN: capivasertib + fulvestrant; alpelisib + fulvestrant. Any genotype after CDK4/6: gedatolisib + palbociclib + fulvestrant (PIK3CA-wild-type, 2026); everolimus + exemestane or giredestrant (filed); abemaciclib switch (postMONARCH, modest).
- Am I a candidate for Gedatolisib, Elacestrant, Imlunestrant or related drugs, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
- How do the results of EMBER-3 and EMERALD apply to someone like me?Trial populations differ from individual patients; ask how closely you match.
Metastatic, endocrine-resistant: ADC before chemotherapy
- For my situation (metastatic, endocrine-resistant: adc before chemotherapy), which of the standard options do you recommend and why?Guideline options include: HER2-low or ultralow (~60%): T-DXd (DESTINY-Breast06 chemotherapy-naive; DESTINY-Breast04 after chemotherapy). HER2-zero: sacituzumab govitecan or Dato-DXd after chemotherapy (TROPiCS-02, TROPION-Breast01).
- Am I a candidate for Trastuzumab deruxtecan, Sacituzumab govitecan, Datopotamab deruxtecan, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
- How do the results of DESTINY-Breast06 and DESTINY-Breast04 apply to someone like me?Trial populations differ from individual patients; ask how closely you match.
Metastatic, chemotherapy and later lines
- For my situation (metastatic, chemotherapy and later lines), which of the standard options do you recommend and why?Guideline options include: Sequential single-agent chemotherapy (capecitabine, taxanes, eribulin, vinorelbine); olaparib/talazoparib if gBRCA; clinical trials; supportive and palliative care integrated early.
- Am I a candidate for Paclitaxel / nab-paclitaxel, Olaparib, Talazoparib, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
Bone-predominant disease and survivorship
- For my situation (bone-predominant disease and survivorship), which of the standard options do you recommend and why?Guideline options include: Bisphosphonate or denosumab for bone metastases and AI-induced bone loss; adjuvant bisphosphonates in postmenopausal women; exercise, cardio-oncology, and adherence support.
Any stage
- Are there clinical trials I could join, for example of Vepdegestrant, Sacituzumab tirumotecan, Datopotamab deruxtecan, ArteraAI Breast?Trials are how the next standard of care is set; asking early keeps options open.
- Would a second opinion at a high-volume centre change anything, and can you help arrange it?Rare or high-stakes decisions benefit from a centre that treats many similar patients.
- What supportive care (symptom control, nutrition, exercise, mental health, financial help) is available from the start?Supportive care improves quality of life and helps patients complete treatment.
- I read that “Late recurrence (up to 20+ years) with no predictive test”. How does that affect my plan?Open problems are where trials and second opinions matter most.
- I read that “CDK4/6 resistance mechanisms and sequencing”. How does that affect my plan?Open problems are where trials and second opinions matter most.
Trials open now for this cancer in OnCo, largest phase first. Joining a trial is a decision like any other: ask what the comparison arm is, whether a placebo is used, and what happens if you leave. The cancer page searches ClinicalTrials.gov live for more.
- A Clinical Study of Neoadjuvant Treatment With TQB2102 for Injection for Human Epidermal Growth Factor Receptor 2 (HER2) Positive Breast CancerPhase 3 · recruiting · NCT07043725A Randomized, Open-label, Multicenter, Parallel-controlled Phase III Clinical Trial to Evaluate the Efficacy and Safety of TQB2102 for Injection Versus TCbHP in Neoadjuvant Treatment of Breast Cancer With Positive HER2 Expression
- A Clinical Study of TQB2102 Versus Docetaxel Plus Trastuzumab and Pertuzumab in the Treatment of HER2 Positive Recurrent or Metastatic Breast CancerPhase 3 · recruiting · NCT07003074A Randomized, Open, Multicenter, Parallel-controlled Phase III Clinical Trial to Evaluate the Efficacy and Safety of TQB2102 for Injection Versus Docetaxel Plus Trastuzumab and Pertuzumab in the Treatment of Human Epidermal Growth Factor Receptor 2 (HER2) Positive Recurrent or Metastatic Breast Cancer
- A Clinical Trial of TQB2102 for Injection in the Treatment of HER2 Low-Expressing Recurrent/Metastatic Breast CancerPhase 3 · active · NCT06561607A Randomized, Open, Parallel-Controlled Phase III Clinical Trial Evaluating the Efficacy and Safety of TQB2102 for Injection Versus Investigator-Selected Chemotherapy in HER2 Low-Expressing Recurrent/Metastatic Breast Cancer
- A Comparative Study of AZD9833 Plus Palbociclib Versus Anastrozole Plus Palbociclib in Patients With ER-Positive HER2 Negative Breast Cancer Who Have Not Received Any Systemic Treatment for Advanced DiseasePhase 3 · active · NCT04711252SERENA-4: A Randomised, Multicentre, Double-Blind, Phase III Study of AZD9833 (an Oral SERD) Plus Palbociclib Versus Anastrozole Plus Palbociclib for the Treatment of Patients With Estrogen Receptor-Positive, HER2-Negative Advanced Breast Cancer Who Have Not Received Any Systemic Treatment for Advanced Disease
- A Phase 3 Study of HRS-8080 Versus Treatment Chosen by Physicians in Locally Advanced and Metastatic Breast CancerPhase 3 · recruiting · NCT07024173A Multicenter, Open-label, Randomized Controlled Phase 3 Study of HRS-8080 Versus Treatment Chosen by Physicians in Locally Advanced and Metastatic Breast Cancer With Disease Progression After Previous Endocrine Therapy
Much of what helps in the first weeks is free if you know to ask: testing, helplines, rides and lodging, second opinions, trial travel.
- HR-positive / HER2-negative breast cancer: the full pageHR-positive breast cancer is the most common breast cancer, driven by oestrogen. It was treated for years with hormone-blocking pills, now joined by CDK4/6 inhibitors, PI3K-pathway drugs, degraders, and ADCs.
- One-page appointment sheetYour questions, the words you may hear, what to bring, and space for the answers. Print it.
- Treatment journey: Stage I-II (early)Surgery first, a genomic test to decide whether chemotherapy adds anything, a few weeks of radiotherapy, then five to ten years of endocrine tablets, with a CDK4/6 inhibitor for two or three years if the risk is high.
- Guidelines comparedNCCN, ESMO and NICE side by side for this cancer.
- Treatment sequencingWhich treatment tends to follow which, line by line.
- NavigatorStandard of care for your stage, what you have tried, and trials near you.
Words this page and the cancer page use
- ESR1 mutation: A change in the oestrogen receptor gene that lets the cancer grow without oestrogen, so aromatase inhibitors stop working.
- Aromatase inhibitor: Pills that stop the body making oestrogen (after the menopause, when it comes from fat and muscle rather than the ovaries), starving hormone receptor-positive breast cancer.
- Selective oestrogen receptor degrader (SERD): Drugs that do not just block the oestrogen receptor but mark it for destruction, so the cancer cell loses the receptor altogether.
- Endocrine resistance: When hormone therapy stops controlling a hormone-driven breast cancer, either quickly (primary) or after years (acquired).
- Oral SERD: An oral SERD is a pill that destroys the oestrogen receptor rather than just blocking it, replacing the monthly fulvestrant injection.
- Ovarian function suppression (OFS): Temporarily switching off the ovaries with injections (or removing them) so a premenopausal woman's cancer is starved of oestrogen.
- HER2-low and HER2-ultralow: Tumours with a little HER2 (IHC 1+ or 2+ without amplification), or a trace (ultralow), which older HER2 drugs ignored but Enhertu can attack.
- Hormone therapy: Treatment that starves cancers which grow in response to a hormone, mainly oestrogen in breast cancer and testosterone in prostate cancer, by lowering the hormone or blocking its receptor.
- Late recurrence: Hormone-driven breast cancer can come back 10 or even 20 years after treatment, unlike most cancers, which is why hormone therapy lasts so long.
- Ductal carcinoma in situ (DCIS): Breast cancer cells confined inside the milk ducts, found mostly by mammography as calcifications.
Every term links to the glossary.