Phase II trial of capecitabine and oxaliplatin in patients with adeno- and undifferentiated carcinoma of unknown primary.

BACKGROUND: Carcinomas of unknown primary (CUP) account for approximately 2-5% of all cancer diagnoses. Except for some subsets with favorable prognosis, for most of these patients treatment options are limited, and no standard first-line regimen has been identified. We performed a phase II study with oxaliplatin (OX) and capecitabine (CAP) as first-line treatment for patients with histo-or cytologically proven adeno- or undifferentiated CUP. PATIENTS AND METHODS: Protocol treatment in this multicenter trial consisted of CAP 1,000 mg/m(2) twice daily orally (days 1-14) and OX 130 mg/m(2) intravenously (day 1), repeated every 21 days at a maximum of 6 cycles. The primary endpoint was the response rate (RR). Secondary endpoints were progression-free survival (PFS), overall survival (OS), and safety. RESULTS: 51 patients with CUP (71% with poorly differentiated adenocarcinoma; 41% ECOG performance status (PS) 0, 39% PS 1, 10% PS 2, 55% with elevated lactate dehydrogenase (LDH), and 39% with liver metastases) were enrolled in this study. We observed an objective RR of 11.7% and a median PFS of 2.5 months as well as an OS of 7.5 months with a good toxicity profile. CONCLUSION: CAP/OX did not reach higher RR compared to a standard regimen with paclitaxel/carboplatin, which discourages further investigation of this schedule in CUP.