Purpose: Platinum-doublet chemotherapy regimens have been shown to extend survival in fit patients with advanced non-small-cell lung cancer (AdvNSCLC). This study extends recent population-based analyses focusing on treatment and survival benefit from use of platinum-doublet therapy, and addressing the role of performance status (PS).
Patients and methods: Patients >or= 66 years with AdvNSCLC incident from 1997 to 2002 were identified in SEER-Medicare. Multivariate models examined tumor and patient characteristics associated with receipt of any chemotherapy and receipt of platinum-doublet compared with single-agent therapy. Nonparametric models estimated treatment effects on survival. Models controlled for patient characteristics, including a novel method to use claims-based indicators to characterize PS. Propensity score analysis adjusted for confounding.
Results: Of the 21,285 patients, 25.8% received first-line chemotherapy. Multivariate analyses indicate lower use of any chemotherapy and platinum-based doublet regimens with increasing age, comorbidity, and poor PS. Receipt of any chemotherapy was associated with reduction in the adjusted hazard of death (0.558; 95% CI, 0.547 to 0.569) and an increase in adjusted 1-year survival from 11.6% (95% CI, 11.1 to 12.0) to 27.0% (95% CI, 26.4 to 27.6). Platinum-doublet receipt increased adjusted 1-year survival over single agents, from 19.4% (95% CI, 18.3 to 20.4) to 30.1% (95% CI, 28.9 to 31.4).
Conclusion: Most elderly patients with AdvNSCLC do not receive chemotherapy, yet there are clear survival benefits, even with controls for age, comorbidity, and PS. The benefit of platinum-based doublet regimens is greater than single-agent chemotherapy. Claims-based proxy indicators of poor PS were independent predictors of treatment and merit further exploration.