The majority of chemotherapy-treated small cell lung cancers(SCLC) patients eventually recur. Although many patients are in excellent physical condition at the time of recurrence, few drugs or drug comb inations are capable of effecting a tumor regression in this setting. Topotecan, a topoisomerase I inhibitor, is one of the more widely studied single agents in SCLC. The aim of theis study was to determine the response rate survival and toxicity of topotecan as a second line treatment in SCLS.

19 patients with measurable SCLC, progressive during the first line chemotherapy (9 cases) or recurrent after the first line chemotherpy(10 cases), were enrolled in this study. Topotecan was administered as a 30-minute daily infusion at a dose of 1.5mg/m² for 5 consecutive days, every 3 week.

The overall response rate was 26.3%(5/19, CR 2, PR 3, SD3, PD 11). The median survival was 24 weeks. The response rate and survival were poor in the nonresponders during first chemotherapy, those who were refractory to the first chemotherapy (recurrent within 3 months after complection of first chemotherapy and extensive disease, but the results were not statistically significant. The toxicities were mainly hematologic and anemia grade III 1/90, leukopenia grade III 6/90 IV 4/90, thrombocytopenia grade III 1/90 IV 1/90, vomiting grade III 1/90 of cycles were occurred. There was no treatment-related deaths due to severe myelosuppression.

Topotecan can be an active second line chemotherpeutic agent for treating SCLC.