Surgery for a Cancer of Unknown Primary
Surgery is used to treat many types of cancer, if they are found at an early stage. But because cancers of unknown primary (CUP) have already spread beyond the site where they started, surgery is less likely to be helpful. Surgery is not recommended for most patients with CUP.
Surgery might be an option if the cancer is found only in the lymph nodes or in one organ, and the surgeon might be able to remove it all. However, there is still a chance that the cancer may be somewhere else in the body. If you are considering surgery as a treatment option, it is important to understand how likely it is to help you.
The type and extent of surgery will depend on where the cancer is and how much there s . If surgery is used, it may be followed by radiation therapy and possibly chemotherapy to try to kill any remaining cancer cells in the body. Sometimes, radiation or chemotherapy is given first to help shrink tumors and make surgery easier.
More information about surgery
For more general information about surgery as a treatment for cancer, see Cancer Surgery.
To learn about some of the side effects listed here and how to manage them, see Managing Cancer-related Side Effects.
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- References
Developed by the American Cancer Society medical and editorial content team with medical review and contribution by the American Society of Clinical Oncology (ASCO).
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National Cancer Institute. Physician Data Query (PDQ). Cancer of Unknown Primary Treatment. 05/06/2024. Accessed at: https://www.cancer.gov/types/unknown-primary/hp/unknown-primary-treatment-pdq on April 22, 2025.
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Tomuleasa C, Zaharie F, Muresan MS, et al. How to diagnose and treat a cancer of unknown primary site. J Gastrointestin Liver Dis. 2017 Mar;26(1):69-79. doi: 10.15403/jgld.2014.1121.261.haz.
Varadhachary GR, Lenzi R, Raber MN, Abbruzzese JL. Carcinoma of Unknown Primary In: Neiderhuber JE, Armitage JO, Doroshow JH, Kastan MB, Tepper JE, eds. Abeloff’s Clinical Oncology. 5th ed. Philadelphia, PA. Elsevier: 2014:1792-1803.
Last Revised: May 27, 2025
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