Can a Cancer of Unknown Primary Be Found Early?
By the time they are diagnosed, cancers of unknown primary (CUP) have always spread outside the organ where they started. If they had been found early, we would know where they started, and they would not be considered a cancer of unknown primary.
Screening tests
The American Cancer Society has specific recommendations about tests that may help detect breast, prostate, cervical, lung, and colorectal cancers early, before they cause any symptoms.
But these cancers account for a small portion of cancers of unknown primary. No screening tests have been proven to be effective in the early detection of many of the cancers that are likely to be diagnosed as cancer of unknown primary, such as pancreatic, stomach, and kidney cancers.
- Written by
- 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).
Bochtler T, Löffler H, Krämer A. Diagnosis and management of metastatic neoplasms with unknown primary. Semin Diagn Pathol. 2017 Nov;26(pii). doi: 10.1053/j.semdp.2017.11.013. [Epub ahead of print].
Crawford SM, Skinner J, Coombes E, Jones AP. Cancer of unknown primary: A cancer registry Study of factors affecting access to diagnosis. Clin Oncol (R Coll Radiol). 2017 Jan;29(1):e39-e46. doi: 10.1016/j.clon.2016.09.011.
Greco FA, Hainsworth JD. Carcinoma of Unknown Primary In: DeVita VT, Lawrence TS, Rosenberg SA, eds. DeVita, Hellman, and Rosenberg’s Cancer: Principles and Practice of Oncology. 10th ed. Philadelphia, PA: Lippincott Williams & Wilkins 2015: 1719-1736.
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
American Cancer Society medical information is copyrighted material. For reprint requests, please see our Content Usage Policy.
American Cancer Society Emails
Sign up to stay up-to-date with news, valuable information, and ways to get involved with the American Cancer Society.
