CUP and chemotherapy: what have we learnt?

Chemotherapy is the backbone of treatment forpatients with CUP. Most patients with unknown primary adenocarcinoma or poorly differentiated carcinoma do not conform to any previously defined "treatable" or favourable subset. To our knowledge, no randomized trial comparing chemotherapy vs best supportive care has been conducted in CUP to date. Nevertheless, patients with CUP can now attain substantial clinical benefit and prolongation of survival from the new cytotoxic drug combinations. The standard therapy for patients with CUP is a combination of platinum with a recently developed cytotoxic agent (gemcitabine, taxane, irinotecan), and the median overall survival is eight months. Future strategies could be based on the use of molecular identification of primary and identification of new biological targets, and integrate chemotherapy and molecular targeted therapies.