Treatments for extragonadal germ cell tumours of unknown primary

Last medical review:

Germ cells are usually found in the testicles or ovaries. But sometimes they can be outside of the testicles or ovaries. When cancer starts in these cells, it is called an extragonadal germ cell tumour. (Extragonadal means outside of the gonads, which are the ovaries and testicles.)

Extragonadal germ cell tumours of unknown primary are usually found at the back of abdomen (called the retroperitoneum) or in the middle of the chest (called the mediastinum).

Chemotherapy is the main treatment for extragonadal germ cell tumours of unknown primary.

If you were born with testicles, you may be offered chemotherapy for testicular cancer.

If you were born with ovaries, you may be offered chemotherapy for germ cell ovarian cancer.

Clinical trials

Talk to your doctor about clinical trials open to people with CUP in Canada. Clinical trials look at new ways to prevent, find and treat cancer. Find out more about clinical trials.

If you can’t have or don’t want cancer treatment

You may want to consider a type of care to make you feel better without treating the cancer itself. This may be because the cancer treatments don't work anymore, they're not likely to improve your condition or they may cause side effects that are hard to cope with. There may also be other reasons why you can't have or don't want cancer treatment.

Talk to your healthcare team. They can help you choose care and treatment for advanced cancer.

Expert review and references

  • Tien Le , MD, FRCSC, DABOG
  • American Cancer Society . Treating a Cancer of Unknown Primary . 2018 :
  • American Society of Clinical Oncology (ASCO). Unknown Primary: Types of Treatment. 2021:
  • Fizazi K, Greco FA, Pavlidis N, Daugaard G, Oien K, Pentheroudakis G . Cancers of unknown primary site: ESMO clinical practice guidelines for diagnosis, treatment and follow-up . Annals of Oncology . 2015 : 26(Supplement 5):v133–v138 .
  • PDQ Adult Treatment Editorial Board. Carcinoma of Unknown Primary Treatment (PDQ®) – Health Professional Version. Bethesda, MD: National Cancer Institute; 2018:
  • National Comprehensive Cancer Network . NCCN Clinical Practice Guidelines in Oncology: Occult Primary (Cancer of Unknown Primary) Version 1.2023 . 2022 .
  • Yentz S, Bhave M, Cobain E, Baker L. Cancer of Unknown Primary. DeVita VT Jr., Lawrence TS, Rosenberg SA, eds. DeVita, Hellman, and Rosenberg's Cancer: Principles & Practice of Oncology. 11th ed. Philadelphia, PA: Wolters Kluwer; 2019: Kindle version, ch 108, .
  • Tan WW . Medscape Reference: Metastatic Cancer With Unknown Primary Site . 2022 :

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