The first 60 days: Cancer of unknown primary, favourable subsets
Favourable subsets of cancer of unknown primary are the roughly one in five cases where the pattern of spread, the microscope appearance or blood markers point strongly to a particular cancer even though no primary can be found. They are treated as that cancer would be, for example breast cancer for a woman with cancer only in armpit nodes, and many are curable or controllable for years. Below, week by week, is what OnCo's record of Cancer of unknown primary, favourable subsets 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.
What happens now
Staging tests establish exactly what and where the cancer is. Everything else follows from the answers.
Histology with directed immunohistochemistry, CT of chest, abdomen and pelvis, sex-specific examinations and tumour markers, PET-CT for cervical node squamous carcinoma and single-site disease.
Ask which of these were tested and what the results were; see the report reader for what each value means.
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: Work-up, Midline poorly differentiated carcinoma in a young man.
- RadiologistNamed in the standard of care for: Work-up.
- SurgeonNamed in the standard of care for: Axillary node adenocarcinoma in a woman, Peritoneal serous carcinoma in a woman, Single metastasis.
- Medical oncologistNamed in the standard of care for: Axillary node adenocarcinoma in a woman, Peritoneal serous carcinoma in a woman, Cervical node squamous carcinoma, Midline poorly differentiated carcinoma in a young man and 2 more.
- Clinical oncologist (radiotherapy)Named in the standard of care for: Axillary node adenocarcinoma in a woman, Cervical node squamous carcinoma, Neuroendocrine carcinoma of unknown primary, Single metastasis.
- Transplant and cell therapy teamNamed in the standard of care for: Midline poorly differentiated carcinoma in a young man.
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.Axillary node adenocarcinoma in a womanESMO Clinical Practice Guideline on cancer of unknown primary 2023
Treat as node-positive breast cancer: axillary dissection, breast radiotherapy or mastectomy, systemic therapy by receptor status.
- 2.Peritoneal serous carcinoma in a womanESMO Clinical Practice Guideline on cancer of unknown primary 2023
Treat as advanced ovarian cancer: cytoreductive surgery and carboplatin-paclitaxel with maintenance as indicated.
- 3.Cervical node squamous carcinomaESMO Clinical Practice Guideline on cancer of unknown primary 2023
Treat as head and neck cancer: HPV and EBV testing, neck dissection or chemoradiotherapy with cisplatin.
- 4.Midline poorly differentiated carcinoma in a young manESMO Clinical Practice Guideline on cancer of unknown primary 2023
Treat as extragonadal germ cell tumour with cisplatin-based combination chemotherapy.
- 5.Neuroendocrine carcinoma of unknown primaryESMO Clinical Practice Guideline on cancer of unknown primary 2023
Platinum-etoposide as for extrapulmonary neuroendocrine carcinoma; somatostatin analogues and radioligand therapy for well-differentiated tumours.
Resection or stereotactic radiotherapy with curative intent.
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 Directed immunohistochemistry panel, Serum PSA, alpha-fetoprotein and hCG, CA-125, HPVand EBV testing in cervical node squamous carcinoma, Oestrogen receptor and HER2 in axillary node adenocarcinoma, Tissue-of-origin classifier), 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 Adenocarcinoma confined to axillary nodes in a woman, Serous papillary peritoneal carcinoma in a woman, Squamous cell carcinoma in cervical nodes.
- Is germline (inherited) genetic testing recommended for me or my family?Inherited variants can change treatment and matter for relatives.
Work-up
- For my situation (work-up), which of the standard options do you recommend and why?Guideline options include: Histology with directed immunohistochemistry, CT of chest, abdomen and pelvis, sex-specific examinations and tumour markers, PET-CT for cervical node squamous carcinoma and single-site disease.
Axillary node adenocarcinoma in a woman
- For my situation (axillary node adenocarcinoma in a woman), which of the standard options do you recommend and why?Guideline options include: Treat as node-positive breast cancer: axillary dissection, breast radiotherapy or mastectomy, systemic therapy by receptor status.
Peritoneal serous carcinoma in a woman
- For my situation (peritoneal serous carcinoma in a woman), which of the standard options do you recommend and why?Guideline options include: Treat as advanced ovarian cancer: cytoreductive surgery and carboplatin-paclitaxel with maintenance as indicated.
- Am I a candidate for Carboplatin, Paclitaxel / nab-paclitaxel, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
Cervical node squamous carcinoma
- For my situation (cervical node squamous carcinoma), which of the standard options do you recommend and why?Guideline options include: Treat as head and neck cancer: HPV and EBV testing, neck dissection or chemoradiotherapy with cisplatin.
- Am I a candidate for Cisplatin, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
Midline poorly differentiated carcinoma in a young man
- For my situation (midline poorly differentiated carcinoma in a young man), which of the standard options do you recommend and why?Guideline options include: Treat as extragonadal germ cell tumour with cisplatin-based combination chemotherapy.
- Am I a candidate for Cisplatin, Etoposide, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
Neuroendocrine carcinoma of unknown primary
- For my situation (neuroendocrine carcinoma of unknown primary), which of the standard options do you recommend and why?Guideline options include: Platinum-etoposide as for extrapulmonary neuroendocrine carcinoma; somatostatin analogues and radioligand therapy for well-differentiated tumours.
- Am I a candidate for Platinum + etoposide (EP / CE), Somatostatin analogues (octreotide, lanreotide), Lutetium-177 dotatate, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
Single metastasis
- For my situation (single metastasis), which of the standard options do you recommend and why?Guideline options include: Resection or stereotactic radiotherapy with curative intent.
Any stage
- Are there clinical trials I could join, for example of Comprehensive genomic profiling, DNA methylation profiling, Liquid biopsy (ctDNA)?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 “Some favourable subsets rest on small series decades old”. How does that affect my plan?Open problems are where trials and second opinions matter most.
- I read that “Whether a tissue-of-origin classifier should ever override the clinical picture is unsettled”. How does that affect my plan?Open problems are where trials and second opinions matter most.
Much of what helps in the first weeks is free if you know to ask: testing, helplines, rides and lodging, second opinions, trial travel.
- Cancer of unknown primary, favourable subsets: the full pageFavourable subsets of cancer of unknown primary are the roughly one in five cases where the pattern of spread, the microscope appearance or blood markers point strongly to a particular cancer even though no primary can be found. They are treated as that cancer would be, for example breast cancer for a woman with cancer only in armpit nodes, and many are curable or controllable for years.
- One-page appointment sheetYour questions, the words you may hear, what to bring, and space for the answers. Print it.
- Treatment sequencingWhich treatment tends to follow which, line by line.
- NavigatorStandard of care for your stage, what you have tried, and trials near you.
- Primary tumour: The original tumour where a cancer started.
- Immunohistochemistry (IHC): Staining a tissue slice with antibodies so a protein shows up in colour under the microscope.
- Debulking (cytoreductive surgery): Surgery that removes as much tumour as possible when it cannot all be removed cleanly; leaving nothing visible behind is what matters.
- Tumour markers (CEA, LDH, chromogranin, thyroglobulin): Substances released into the blood by some cancers that can be measured with a simple test, useful for tracking whether treatment is working or the cancer is coming back, but rarely good enough to diagnose or screen.
- HPV-positive (p16) head and neck cancer: Throat cancers caused by the human papillomavirus, identified by a p16 stain.
- Lymphadenectomy (lymph node dissection): Surgically removing the lymph nodes that drain a tumour, both to stage the cancer and to clear any spread.
- Chemoradiation (chemoradiotherapy, CRT): Radiotherapy given at the same time as chemotherapy, which sensitises the cancer to radiation.
Every term links to the glossary.