Sarcomas, rare & complex cancers
Cancer types
Cancer of unknown primary
Soft tissue sarcomas, bone tumours, GIST, neuroendocrine tumours and cancers of unknown primary.
Soft tissue sarcomas, bone tumours, GIST, neuroendocrine tumours and cancers of unknown primary.
This map explains cancer of unknown primary (CUP) step by step: what it is, the types, the tests, the stages, the treatment and its side effects.
Tap any topic on the map to read about it. Topics with an arrow open more topics.
Some patterns behave like a particular cancer and are treated that way. Tap a group on the map.
Most patients. Treated with chemotherapy, and with targeted treatment or immunotherapy if NGS finds a suitable change.
Tap a test on the map to see why it is done.
Please wait for all the reports. Why we wait
Special stains on the biopsy suggest the most likely starting site (for example lung, breast, bowel).
Search for the starting site and show all areas of spread.
Tumour markers, mammogram, endoscopies or other tests, guided by the symptoms and biopsy, not all at once.
Genetic tests on the tumour can find treatable mutations and sometimes point to the starting site.
Before starting chemotherapy, immunotherapy or targeted therapy, these tests check that you are fit for treatment, and give a starting point to compare with later.
| Test | Why it is done |
|---|---|
| CBC (complete blood count) | Haemoglobin, white cells and platelets. Treatment can lower them. |
| RFT (kidney function) | Many medicines are cleared by the kidneys; the dose may need to change. |
| LFT (liver function) | Many medicines are processed by the liver. |
| Viral markers: HBsAg, anti-HCV, HIV | Hepatitis B can flare up during treatment. If positive, a tablet is given to prevent this. |
| Blood sugar (and HbA1c if diabetic) | Steroids given with chemotherapy can raise blood sugar. |
| ECG and 2D Echo | Check the heart rhythm and pumping before treatment, as some medicines affect the heart. |
Before immunotherapy, also:
| Test | Why it is done |
|---|---|
| Serum TSH (thyroid) | Immunotherapy can affect the thyroid gland. |
| Serum cortisol (morning sample) | Immunotherapy can affect the adrenal and pituitary glands. |
Sometimes needed, depending on your treatment:
Your doctor will choose the tests that apply to you. Some of them are repeated during treatment.
Tap your group on the map.
Treated in the same way as the cancer they resemble (breast, ovarian, head and neck, prostate, neuroendocrine), often with good results.
Side effects: chemotherapy
Tap a treatment on the map.
Fever of 38°C or more during chemotherapy, breathlessness, severe pain, weakness of the legs, or confusion need urgent care.
This information is general. Your own treatment plan may be different. Please discuss it with your doctor.
Written and medically reviewed by Dr Prathyusha Eaga, MD, DM (Medical Oncology). Last reviewed: 12 October 2026. Based on NCCN and ESMO guidelines.
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