Chemotherapy for patients with two favourable subsets of unknown primary carcinoma: Active, but how effective?

Carcinoma of unknown primary ( CUP) is characterized by dismal patient survival. The outcome of patients with two favourable risk CUP subsets was studied. Eighty patients diagnosed with either midline lymph node metastases ( n = 33) or peritoneal carcinomatosis ( n = 47) were analysed retrospectively. The majority had poorly differentiated adenocarcinoma or undifferentiated carcinoma, treated with platinum- taxane based chemotherapy from 1996 till 2002. Females with peritoneal carcinomatosis also underwent surgical debulking. Objective tumour regression was present in 44% of patients ( nodal group 30% versus peritoneal group 53%, p = 0.066). Complete responses were seen more often in peritoneal carcinomatosis patients ( nodal group 9%, peritoneal group 36%, p = 0.008). At a median follow up of 60 months, median progression- free and overall survival were 5 and 10 months respectively in the nodal group, 7 and 15 months in the peritoneal group. Five- year survival was 7% ( nodal group 0% vs. peritoneal group 10%, p = 0.05). Complete responders fared better than non- CR patients. Fewer than four metastatic sites, elevated CA 125, and normal CA 19- 9 levels were favourable prognostic factors for survival. Modern combination chemotherapy has satisfactory activity, with a minority of CUP patients enjoying long- term responses. Research efforts towards complete remission consolidation and molecular profiling are imperative.