A phase II trial of carboplatin in untreated patients with extensive stage small cell lung cancer

Twenty-five untreated patients with extensive stage small cell lung cancer (ESSCLC) were treated with carboplatin (CBDCA) (500 mg/m2) given as a 24-hour infusion every 21 days. Thirteen patients responded for an overall response rate of 52% (95% confidence limits, 32% to 72%) with 3 complete responses (CR) (12%; 95% confidence limits, 0% to 25%). The median duration of response was 4.5 months. The median survival time was 8 months with three long-term survivors (12%) at 27, 33, and 43 months from the start of CBDCA treatment. Ninety-two courses of CBDCA were administered and one treatment-related death occurred. The main toxicity was myelosuppression. Grade 3 or 4 hematologic toxicity (hemoglobin level, less than 8 g/dl; granulocyte count, less than 1900/microliters; and platelet count, less than 49,000/microliters) was observed as follows: neutropenia in 7 courses (8%) and in 7 patients (28%), decreased hemoglobin level in 13 courses (15%) and in 7 patients (28%), and decreased platelet count in 10 courses (11%) all Grade 3 and in 8 patients (32%). This study demonstrates that at this dose and schedule CBDCA is a highly active drug in ESSCLC and it has tolerable toxicity.