First-line systemic treatments for stage IV non-small cell lung cancer in California: Patterns of care and outcomes in a real-world setting

Abstract

Background: Multiple systemic treatments have been developed for stage IV non-small cell lung cancer (NSCLC), but their use and effect on outcomes at the population level are unknown. This study describes the utilization of first-line systemic treatments among stage IV NSCLC patients in California and compares survival among treatment groups. Methods: Data on 17 254 patients diagnosed with stage IV NSCLC from 2012 to 2014 were obtained from the California Cancer Registry. Systemic treatments were classified into six groups. The Kaplan-Meier method and multivariable Cox proportional hazards models were used to compare survival between treatment groups. Results: Fifty-one percent of patients were known to have received systemic treatment. For patients with nonsquamous histology, pemetrexed regimens were the most common treatment (14.8%) followed by tyrosine kinase inhibitors (11.9%) and platinum doublets (11.5%). Few patients received pemetrexed/bevacizumab combinations (4.5%), bevacizumab combinations (3.6%), or single agents (1.7%). There was statistically significantly better overall survival for those on pemetrexed regimens (hazard ratio [HR] = 0.86, 95% confidence interval [CI] = 0.80 to 0.92), bevacizumab regimens (HR = 0.73, 95% CI = 0.65 to 0.81), pemetrexed/bevacizumab regimens (HR = 0.68, 95% CI = 0.61 to 0.76), or tyrosine kinase inhibitors (HR = 0.62, 95% CI = 0.57 to 0.67) compared with platinum doublets. The odds of receiving most systemic treatments decreased with decreasing socioeconomic status. For patients with squamous histology, platinum doublets were predominant (33.7%) and were not found to have statistically significantly different overall survival from single agents. Conclusions: These population-level findings indicate low utilization of systemic treatments, survival differences between treatment groups, and evident treatment disparities by socioeconomic status.