Objective: To assess the role of maintenance or consolidation therapy in the treatment of small-cell lung cancer (SCLC), a meta-analysis of all published randomized clinical trials (RCTs) was performed in order to provide an overall meta-analysis and indirectly compare the effect of chemotherapy, interferons, and other biologic agents.
Methods: Electronic databases were searched for publication reporting of RCTs comparing maintenance or consolidation therapy versus placebo or follow-up alone until December 2008. Hazard ratios (HRs) for progression-free survival (PFS) and overall survival (OS), with their relative 95% confidence intervals (CI), were derived. In the calculation of HRs, the "no maintenance" arm served as a reference. The a priori value of p<0.05 was chosen as significant level for statistical tests.
Results: Twenty-one RCTs, encompassing 3,688 patients, were eligible for the present analysis: 11 RCTs employing chemotherapy, 6 interferons (4 alpha and 2 gamma), and 4 other biological agents. Overall, no statistical advantage in OS (HR 0.93, 95% CI 0.87-1.00; p = 0.05) or in PFS (HR 0.98, 95% CI 0.91-1.06; p = 0.63) was reported for maintenance or consolidation therapy. Statistical evidence of different effects among the four types of therapy was detected for OS (χ(2) test for heterogeneity: 8.07 [3 df]; p = 0.04), but not for PFS. A statistically significant reduction of mortality was detected in those studies assessing the efficacy of chemotherapy (HR 0.89, 95% CI 0.81-0.98; p = 0.02) and of interferon-alpha (HR 0.78, 95% CI 0.64-0.96; p = 0.02).
Conclusions: The maintenance or the consolidation approach failed to improve the outcomes of SCLC. A survival advantage is suggested for maintenance chemotherapy and interferon-alpha, but its clinical impact needs to be confirmed by further studies.
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