Cisplatin and gemcitabine with either vinorelbine or paclitaxel in the treatment of carcinomas of unknown primary site - Results of an Italian multicenter, randomized, phase II study

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/m(2)) and gemcitabine (1000 mg/m(2)) with either paclitaxel (70 mg/m(2)) or vinorelbine (25 mg/m), and all drugs were administered intravenously on Days 1 and 8 of a 21-day cycle. Twenty-nine patients (44%) presented with >= 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.