Time-to-Treatment-Failure and Related Outcomes Among 1000+ Advanced Non–Small Cell Lung Cancer Patients: Comparisons Between Older Versus Younger Patients (Alliance A151711)

Introduction: Time-to-treatment-failure (TTF) is the interval from chemotherapy initiation to premature discontinuation. We evaluated TTF based on age. Methods: Pooled analyses were conducted with first-line chemotherapy trials for advanced NSCLC (CALGB 9730, 30203, and 30801). Comparisons among patients who were 65 years and older and 70 years and older were performed for TTF (primary endpoint), reasons for early chemotherapy cessation, grade 3+ adverse events, and overall survival. Results: Among 1006 patients, 460 (46%) were older than 65 years of age. One hundred forty-five older patients (32% of this age cohort) completed all six planned chemotherapy cycles as did 170 (32%) younger patients. Median TTF was 2.9 months (95% confidence interval: 2.7– 3.2) in older patients and 3 months (95% confidence interval: 2.9–3.5) in younger patients; adjustment for performance status and stratification by chemotherapy by trial yielded no statistically significant age-based difference in TTF. However, reasons for early chemotherapy cessation differed between age groups (multivariate p = 0.004). Older patients were less likely to discontinue from cancer progression (41% versus 55%) and more likely from toxicity or patient choice (16% and 15%, respectively) compared to younger patients (13% and 6%, respectively). Older patients were more likely to experience grade 3+ adverse events (86% versus 79%) with no statistically significant difference in survival. An age cutpoint of 70+ years showed no difference in TTF, a lower trend of early cessation due to cancer progression, and somewhat shorter older patient survival. Conclusions: TTF was comparable between older and younger patients; but different, age-based, and potentially modifiable reasons account for it.