This study assessed the efficacy and toxicity of etoposide and carboplatin(EC) combination regimen as a first line therapy for small cell lung cancer(SCLC), and determined the efficacy and toxicity of topotecan for relapsed SCLC.

One hundred and ten patients with previously untreated SCLC received etoposide(100mg/m² i.v., day 1 to 3) and carboplatin(300mg/m² i.v., day 1) combination chemotherapy every 3 weeks. For patients with relapsed SCLC after EC therapy, topotecan(1.5mg/m²) was administered for 5 consecutive days every 3 weeks. Response rate, survival and toxicity profiles were assessed. Response was recorded as CR(complete remission), PR(partial remission), SD(stable disease) and PD(progressive disease).

One hundred and one patients were assessed for response to EC. Overall response rate to EC was 57.4%(CR 15.8%, PR 41.6%) with a time to progression of 10.3 months(median). The toxicity was tolerable and there was no treatment-related death. Twenty one relapsed SCLC patients were treated with topotecan. Of those who relapsed within 3 months of EC(refractory relapse, RR), 15.4%(2/13) showed PR, while of those who relapsed after 3 months(sensitive relapse, SR), 25%(2/8) exhibited PR. Grade 4 neutropenia was noted in 9.5% and 14.3% showed thrombocytopenia(G4).

The EC regimen showed a moderate response rate for SCLC with minimal toxicity. The use of topotecan for relapsed SCLC warrants further investigation.