Comparative survival analysis of platinum-based adjuvant chemotherapy for early-stage squamous cell carcinoma and adenocarcinoma of the lung.

Abstract

Background and PurposeAlthough cytotoxic platinum‐based adjuvant chemotherapy (pACT) has been recommended for patients with completely resected early‐stage (ES) non–small‐cell lung cancer (ES‐NSCLC), therapeutic regimens for NSCLC have evolved in the past two decades. The study was aimed to examine the effectiveness of postoperative pACT for resected ES‐NSCLC patients with squamous cell carcinoma (SCC) or adenocarcinoma (ADC) according to real‐world data.Methods and PatientsInverse probability treatment weighting (IPTW) was used to adjust baseline characteristics between the group receiving pACT and those not receiving any treatment (observation, OBS) within 3 months after curative surgery. Cox regression models were used to compare overall survival (OS) and treatment failure‐free survival (TFS) between the groups.ResultsOf 31,208 patients with ES‐NSCLC, 4700 undergoing complete tumor resection were eligible, with a mean follow‐up period of 4.5 years. The pACT (n = 2347) and OBS (n = 2353) groups were well‐balanced after IPTW. The median OS differed between the pACT and OBS groups (77.2 vs. 75.5 months, adjusted hazard ratio [aHR] = 0.87, 95% confidence interval [CI] = 0.79–0.95, p = 0.003), and the 5‐year survival rates were 58.2% and 55.3%, respectively (p < 0.001). In the SCC group, pACT was superior to OBS in OS (75.0 vs. 57.4 months, aHR = 0.74, 95% CI = 0.62–0.88, p = 0.001) and TFS (32.7 vs. 21.8 months, aHR = 0.74, 95% CI = 0.63–0.86, p < 0.001). Both OS and TFS did not differ between two groups in those with ADC.ConclusionReal‐world data indicated that pACT confers a survival benefit for resected ES‐NSCLC patients with SCC but not ADC, which needs to be verified by a large sample of randomized controlled studies.