Consolidation chemotherapy improves progression-free survival in stage III small-cell lung cancer following concurrent chemoradiotherapy: a retrospective study

BACKGROUND Concurrent chemoradiotherapy (CCRT) is the standard treatment for limited-stage small-cell lung cancer (LD-SCLC). However, the efficacy of consolidation chemotherapy (CCT) in LD-SCLC remains controversial despite several studies that were performed in the early years of CCT use. The aim of this study was to reevaluate the effectiveness and toxicities associated with CCT. METHODS This retrospective analysis evaluated 177 patients with stage IIIA and IIIB small-cell lung cancer (SCLC) who underwent CCRT from January 2001 to December 2013 at Sun Yat-Sen University Cancer Center (SYSUCC). Overall survival (OS) and progression-free survival (PFS) were analyzed using Kaplan-Meier methods. Univariate and multivariate analyses were performed to analyze patient prognosis factors. RESULTS Among the 177 patients, 72 (41%) received CCT and 105 (59%) did not receive CCT. PFS was significantly better for patients in the CCT group compared to that for patients in the non-CCT group (median PFS: 17.0 vs 12.9 months, respectively, P=0.031), whereas the differences in OS were not statistically significant (median OS: 31.6 vs 24.8 months, respectively, P=0.118). The 3- and 5-year OS rates were 33.3% and 20.8% for patients in the CCT group and 27.6% and 6.7% for patients in the non-CCT group, respectively. Multivariate analysis revealed that having a pretreatment carcinoembryonic antigen level <5 ng/mL (P=0.035), having undergone prophylactic cranial irradiation (P<0.001), and having received CCT (P=0.002) could serve as favorable independent prognostic factors for PFS. Multivariate analysis for OS also showed that having undergone PCI (P<0.001) and having received CCT (P=0.006) were independent significant prognostic factors. CONCLUSION CCT can improve PFS for patients with stage IIIA and IIIB SCLC following CCRT without significantly increasing treatment-related toxicities.