Chemotherapy outcomes by histologic subtypes of non-small-cell lung cancer: Analysis of the southwest oncology group database for antimicrotubule-platinum therapy

Objective Histologic subtyping has been advocated to select chemotherapy for patients with advanced-stage non-small-cell lung cancer (NSCLC). To determine whether histologic subtype was associated with efficacy for the commonly used antimicrotubule (AMT) agents, paclitaxel, docetaxel, and vinorelbine plus a platinum compound, we examined the Southwest Oncology Group (SWOG) lung cancer database. Methods Data from 4 randomized trials (S9308, S9509, S9806, and S0003) administering an AMT agent plus platinum in patients receiving first-line treatment for advanced-stage NSCLC were analyzed. Overall survival (OS) and progression-free survival (PFS) comparisons were performed using Cox proportional hazard regression, adjusting for sex. Median survival times were estimated by Kaplan-Meier. Results Of 1146 patients included in this analysis, 640 had adenocarcinoma (56%), 220 had squamous cell carcinoma (19%), 121 had large cell carcinoma (11%), and 165 had NSCLC not otherwise specified (NOS) (14%). Median OS times by histologic subtypes were 8.5, 8.4, 8.2, and 9.6 months, respectively, and median PFS times were 4.2, 4.3, 4.3, and 4.6 months, respectively. No difference in OS or PFS was observed by histologic subtype and, specifically, between nonsquamous and squamous histologies. Conclusions This pooled analysis from 4 SWOG trials using an AMT-platinum regimen did not show a difference in survival outcomes by histologic subtype. Because the majority of patients with advanced NSCLC continue to receive chemotherapy, defining molecular-based predictive markers of responsiveness is warranted.