Management of patients with cancer of unknown primary site

Cancer of unknown primary site represents approximately 3% to 5% of all new cancer diagnoses. Adenocarcinomas account for 60% of all unknown primary c ancers and poorly, differentiated carcinomas or adenocarcinomas, for 30%, H istorically, the prognosis for most patients with unknown primary tumors ha s been poor, with survival often less than 6 months from diagnosis. Recent advances in diagnostic techniques, including immunocytochemical and molecul ar genetic methods, have increased the probability of identifying a likely underlying tumor type. Based on clinical and pathologic features, approxima tely, 40% of patients can be categorized within subsets for which specific treatment has been defined. Empiric therapy is an option for the remaining 60% of patients, In these patients,favorable prognostic factors for treatme nt response include tumor location in lymph nodes,fewer sites of metastases , younger age, and poorly differentiated carcinoma histology, Although expe rience remains limited, the incorporation of a taxane into empiric regimens appears to improve response rates and survival A recent study of paclitaxe l (Taxol), carboplatin (Paraplatin), and etoposide in 55 patients with canc er of unknown primary site reported an overall response rate of 47% and a m edian overall survival of 13.4 months. Investigations continue to explore n ew diagnostic techniques and novel therapeutic approaches.