Cisplatin in combination with either gemcitabine or irinotecan in carcinomas of unknown primary site: results of a randomized phase II study--trial for the French Study Group on Carcinomas of Unknown Primary (GEFCAPI 01).

PURPOSE

To evaluate the efficacy and toxicity of novel chemotherapy combinations including cisplatin with gemcitabine (GC) or irinotecan (IC) for patients with carcinomas of an unknown primary site.

PATIENTS AND METHODS

Eighty patients were randomly assigned to receive GC or IC. In the GC arm, chemotherapy consisted of cycles combining gemcitabine 1,250 mg/m2 intravenously (IV) on days 1 and 8, and cisplatin 100 mg/m2 IV on day 1 at 3-week intervals. Patients in the IC arm originally received 3-week cycles of irinotecan 200 mg/m2 IV on day 1 and cisplatin 80 mg/m2 IV on day 1. After the inclusion of 15 patients in that arm, the toxicity profile required the irinotecan doses to be reduced to 150 mg/m2 per cycle. Independent histologic and radiologic reviews were done.

RESULTS

A total of 78 patients were assessable for efficacy and toxicity. The median number of cycles was four in each arm. Objective responses were observed in 21 patients (55%) in the GC arm (95% CI, 34% to 66%) and in 15 patients (38%) in the IC arm (95% CI, 23% to 54%). Treatment had to be stopped because of toxicity in seven patients in the GC arm and in eight patients in the IC arm. With a median follow-up of 22 months, the median survivals were 8 and 6 months in the GC and IC arms, respectively.

CONCLUSION

This study demonstrates the activity of both the GC and IC regimens. There was toxicity associated with both regimens. Additional studies of combination chemotherapy regimens are required.