Continuous infusion 5-fluorouracil, etoposide and cis-diamminedichloroplatinum in patients with metastatic carcinoma of unknown primary origin.

We conducted a phase II clinical trial of 5-fluorouracil (5 day continuous infusion), cis-diamminedichloroplatinum and etoposide in previously untreated patients with metastatic carcinoma of unknown primary origin. Of the thirty-six evaluable patients (21 adenocarcinoma, 14 undifferentiated carcinoma and 1 squamous cell carcinoma), eight patients responded to this treatment (4 CR, 4 PR). Responses were seen in both soft tissue and visceral disease. Toxicity was significant and included grade III/IV myelosuppression in over 90% of patients treated. Non-hematologic toxicity included nausea/vomiting and stomatitis. Although the remissions obtained in this study appear to be durable (median duration of complete remission greater than 24 months), the regimen does not appear to offer significant advantages over other less toxic and more easily administered cisplatin-based combinations.