[Comparison of Efficacy and Safety of Different Therapeutic Regimens as Second-line Treatment for Small Cell Lung Cancer].

BACKGROUND AND OBJECTIVE: Small-cell lung cancer (SCLC) is an aggressive disease for which the mainstay of treatment is cytotoxic chemotherapy. Despite good initial responses most patients will relapse or progress after the first-line therapy. The evidence of a benefit from second-line chemotherapy is limited in patients with relapsed/advanced SCLC. Some drugs are recommended by guidelines, but more regimens are formulated based on experience in clinical. So we conducted this retrospective study in order to compare the efficacy and safety of different second-line treatment regimens.

METHODS: We totally analyzed 309 patients received second-line treatment in our retrospective study. 157 patients received best supportive care (BSC), and the rest 152 patients received second-line chemotherapy. The Kaplan-Meier method survival curves and Log-rank test were used to analysis the differences among different groups. The endpoints were objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS).

RESULTS: Patients administered second-line chemotherapy lived significantly longer, with a total OS from first-line therapy of 11.5 mo compared to 6.0 mo in patients with best supportive care alone (P<0.001), and the ORR, DCR, PFS and OS of the former (including the sensitive disease and resistance/refractory disease patients) were obviously better than that of the latter. The ORR and DCR of the patients who received second-line chemotherapy is 39.5% and 59.2%, respectively. The median PFS and OS from second-line chemotherapy were 3.3 mo and 5.3 mo. The patients who received second-line chemotherapy were divided by types of second-line regimens. The sensitive disease patients were from group A (VP-16-based rechallenge) and group B1 (CPT-11-based regimen). The ORR of the two groups were 48.6% and 35.3%, and the DCR were 68.6% and 58.8%, respectively. There was no statistically significant difference (P=0.264; P=0.400). The median PFS from second-line chemotherapy of the two groups were 4.0 mo and 3.0 mo, and the second-line median OS were 6.5 mo and 4.5 mo. There was no statistic difference (P=0.432; P=0.508). The resistance/refractory disease patients were divided into group B2 (CPT-11-based regimen), group C (PTX/DXL-based regimen) and group D (TPT-based regimen). There was no statistic difference in second-line ORR, DCR and median PFS among the three groups (P value is 0.521, 0.528 and 0.775, respectively); The median OS from second-line chemotherapy of the group D is longer than that of group B2 and group C, with statistical difference (P=0.043; P=0.030). The differences of grade III-IV hematologic toxicities among the four subgroups were not statistically different. The incidence of diarrhea in non-hematologic toxicities in patients who received irinotecan as second-line chemotherapy was higher than other three subgroups (P=0.029).

CONCLUSIONS: Patients who progressed after the completion of first-line chemotherapy can gain survival benefit. The response and the PFS of the different second-line chemotherapies were similar. The patients who received the TPT-based regimen may gain longer overall survival than other resistance/refractory disease patients.
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