Superiority of Carboplatin-Based Doublets to Cisplatin-Based Doublets among Medicare Patients Aged 70 and Older with Advanced Lung Cancer

Abstract

Background: Some evidence suggests that cisplatin-based chemotherapy doublet regimens are more effective than the less toxic carboplatin-based doublet regimens for patients with advanced non-small cell lung cancer (NSCLC), but their effectiveness among elderly cancer patients who are treated in usual care settings is not known. Methods: We identified 13,406 elderly Medicare patients who were diagnosed with stage IV NSCLC between the years 1995-2007 in SEER regions and treated with either a cisplatin-based or a carboplatin-based doublet chemotherapy regimen in the subsequent six months. Using propensity score weighting, we balanced the two treatment cohorts with respect to observable attributes. We then estimated survival and morbidity according to treatment. Findings: Overall, patients treated with cisplatin-based doublets lived two weeks longer on average than patients treated with carboplatin-based doublets (i.e., 7.4 months vs. 7.0 months, p=0.05). For patients >70 years of age, first-line therapy with cisplatin-based doublet chemotherapy regimens was associated with increased post-treatment morbidity and lack of survival advantage compared to carboplatin-based doublet therapies. Interpretations: For patients >70 years of age first-line therapy with carboplatinbased doublet chemotherapy regimens are preferable to cisplatin-based doublet therapies given the similar survival and lower risk of hospitalization.