Prognostic factors in carcinomas of unknown primary site

Carcinomas of unknown primary (CUP) site are a heterogeneous group of tumours with widely variable natural histories and poor survival rates. In a minority of patients, the clinical presentation similar to that of known primar cancers at an equivalent stage has resulted in the identification of subsets of patients with favourable clinical and pathological features. Their recognition is of major importance since specific management may prolong survival. For the vast majority of patients with CUP however, the identification of reliable prognostic indicators has proven challenging. A number of studies with multivariate analyses identified poor performance status, liver metastases, abnormal serum lacticodehydrogenase levels, and low serum albumin as main recurrent adverse prognostic factors. Adequate knowledge of prognostic factors may help oncologists in refining the daily management of patients, assessing the results and designing clinical research studies.