Background: : To date, the standard treatment for patients who have carcinoma of unknown primary site has not been established.
Methods: : In this randomized Phase II study, 66 previously untreated patients (33 patients per arm) with carcinomas of unknown primary site received cisplatin (35 mg/m2) and gemcitabine (1000 mg/m2) with either paclitaxel (70 mg/m2) or vinorelbine (25 mg/m2), and all drugs were administered intravenously on Days 1 and 8 of a 21-day cycle. Twenty-nine patients (44%) presented with > or =2 involved sites. The pathologic diagnosis was mainly adenocarcinoma (48 patients; 72.7%) and squamous carcinoma (7 patients; 10.6%).
Results: : In the first arm, 16 patients (48.5%) experienced an objective response, and 9 patients (27.2%) had disease stabilization. In the vinorelbine-containing arm, 14 patients (42.3%) experienced an objective response, and 8 patients (24.2%) had disease stabilization. The median response duration and the median time to progression were similar in both treatment arms; the median overall survival was 9.6 months (95% confidence interval, 7.11-12.09 months) for patients who received the cisplatin/gemcitabine/paclitaxel regimen and 13.6 months (95% confidence interval, 6.61-20.59 months) for patients who received the vinorelbine combination. Grade 3 and 4 toxicities were more frequent in the paclitaxel-containing arm.
Conclusions: : Both combinations satisfied the 2-step design, demonstrating antitumor activity without relevant differences in response rates or response duration; however, the vinorelbine-containing regimen yielded superior results both in terms of overall survival (13.6 months vs 9.6 months) and in terms of treatment tolerability. Therefore, according to a pick the winner attitude, the combination of cisplatin/gemcitabine/vinorelbine may be considered in the design of future randomized, Phase III trials for patients with carcinomas of unknown primary site.
Copyright 2006 American Cancer Society.