Cancer of unknown primary origin

"Cancer of unknown primary origin" (CUP, "occult cancer") is a term used to describe a cancer that is said to be at the metastatic stage at the time of diagnosis, but a primary tumor cannot be identified. A diagnosis of CUP requires a clinical picture with metastatic disease and one or more biopsy results inconsistent with a primary tumor.^[1]

CUP is found in about 3 to 5% of all people diagnosed with invasive cancer,^[2] and carries a poor prognosis in most (80 to 85%) of those circumstances. The other 15 to 20% of patients, however, have a relatively long survival with appropriate treatment.^[2]

1. ↑ "Carcinoma of Unknown Primary Treatment–for health professionals". National Cancer Institute. December 30, 2014. Retrieved 6 July 2015.
2. ↑ ^{2.0 2.1} Stella, GM; Senetta, R; Cassenti, A; Ronco, M; Cassoni, P (24 January 2012). "Cancers of unknown primary origin: current perspectives and future therapeutic strategies". Journal of Translational Medicine. 10: 12. doi:10.1186/1479-5876-10-12. PMC 3315427. PMID 22272606.