Do older patients with non-small cell lung cancer also benefit from first-line platinum-based doublet chemotherapy? Observations from a pooled analysis of 730 prospectively-treated patients (Alliance Study A151622)

Objective: This study sought to define the role of first-line platinum-based doublet chemotherapy in older patients with non-small cell lung cancer (NSCLC). Materials and Methods: We analyzed three first-line NSCLC trials: CALGB 9730, CALGB 30203, and CALGB 30801, which tested carboplatin and paclitaxel; carboplatin and gemcitabine; and carboplatin with either pemetrexed or gemcitabine, respectively. Overall survival was the primary endpoint. Age-based comparisons with a cutpoint of 65 years were performed with Cox proportional hazards models with adjustments for sex, tumor histology, cancer stage, chemotherapy, and smoking history and after stratifying by performance score. Secondary endpoints were grade 3–5 adverse events, chemotherapy cycles completed, and whether toxicity prompted chemotherapy discontinuation. Results: 730 patients were included; 337 (46%) were 65+ years of age. No statistically significant difference in survival was observed for older (≥65) versus younger patients (HR = 1.096; 95% CI = (0.94, 1.28); p = 0.25). A trend emerged with increased odds of a grade 3–5 adverse event for patients ≥65 years versus <65 years (OR = 1.52; 95% CI = (0.99, 2.31); p = 0.05). The proportion of completed chemotherapy cycles was marginally lower in older patients (difference = −5%; 95% CI = (−9, 0.2); p = 0.06) for those ≥65 years versus <65 years, but no statistically significant difference occurred in the rate of chemotherapy discontinuation for toxicity (OR = 1.4; 95% CI = (0.85, 2.19); p = 0.21) for patients ≥65 years versus <65 years. A cutpoint of 70 years yielded similar results. Conclusion: These findings support carboplatin doublet-based chemotherapy in select older patients with advanced NSCLC.