Comparison between single-agent and combination chemotherapy as second-line treatment for advanced non-small cell lung cancer: a multi-institutional retrospective analysis

Purpose Doublet combination chemotherapy is commonly considered a second-line treatment for advanced non-small cell lung cancer (NSCLC) in China. This multi-institutional retrospective analysis evaluated and compared the efficacy between combination and mono-therapy after platinum-based first-line chemotherapy in Chinese patients with advanced NSCLC. Methods We retrospectively reviewed 335 patients who received second-line chemotherapy for advanced NSCLC. The primary endpoint was overall survival (OS), and the secondary endpoints were progression-free survival (PFS), response rate (RR) and toxicity. Treatment-free interval (TFI) was used for further stratification analysis. The Cox proportional hazards model was used for multivariate analysis. Results Two hundred and fifty-three patients received doublet combination chemotherapy and 82 received single-agent chemotherapy. PFS was significantly prolonged in combination group compared to single-agent group (median 5.70 vs 3.70 months; HR 0.62; 95% CI 0.45–0.85; p < 0.001). The RR was significantly higher in the combination group than in the single-agent group (29.25% vs. 10.98%; p = 0.001). OS was also prolonged in combination group versus single-agent group (median 13.30 vs. 11.45 months, respectively; HR 0.70; 95% CI 0.52–0.95; p = 0.023). Among patients with TFI of ≥ 6 months, PFS and OS of the combination group were significantly increased than the single-agent group (median PFS, 6.67 vs. 3.80 months, p = 0.002; median OS, 13.60 vs. 11.45 months, p = 0.013). Grade III/IV toxicity was similar between the two groups ( p = 0.113). Through multivariate analyses, we found that Eastern Cooperative Oncology Group (ECOG) score ( p < 0.001), further-line treatment ( p < 0.001) and combination chemotherapy ( p = 0.024) were the independent prognostic factors. Conclusion Compared with mono-therapy, combination chemotherapy was a better second-line option for Chinese patients with good performance status, especially in those with TFI of ≥ 6 months.