Relative dose intensity of first-line chemotherapy and overall survival in patients with advanced non-small-cell lung cancer

PURPOSE: The effects of chemotherapy dose intensity on survival in patients with advanced non-small-cell lung cancer (NSCLC) are poorly understood. We retrospectively analyzed dose delays/reduction, relative dose intensity (RDI), and the association between chemotherapy intensity and survival in advanced NSCLC. METHODS: This retrospective cohort study included adults with advanced lung cancer who received first-line myelosuppressive platinum-based chemotherapy (January 2007–December 2010) in ~ 230 US Oncology Network community practices. Dose delays ≥ 7 days, dose reductions ≥ 15%, and RDI relative to standard regimens were described. Overall survival (OS) was measured using Kaplan-Meier and Cox proportional hazard (PH) models. RESULTS: Among 3866 patients with advanced NSCLC, 32.4% experienced dose delays ≥ 7 days, 50.1% experienced dose reductions ≥ 15%, and 40.4% had RDI < 85%. Reduced RDI was also common regardless of baseline ECOG PS (ECOG PS ≥ 2, 56.2%; ECOG PS 0, 33.6%) and tumor subgroup (squamous cell carcinoma, 52.2%; adenocarcinoma, 36.0%). When stratified by chemotherapy intensity measures, significant OS differences were observed only for dose delays. Median (95% CI) OS was 1.02 years (0.96–1.12) for dose delays ≥ 7 days and 0.71 years (0.66–0.77) for dose delays < 7 days. In multivariable Cox PH analysis, dose delays ≥ 7 days (HR = 0.71; 95% CI = 0.63–0.80) and RDI ≥ 85% (HR = 1.18; 95% CI = 1.05–1.32) were significantly associated with decreased mortality. CONCLUSIONS: Dose delays, dose reductions, and reduced RDI were common, and dose delays ≥ 7 days and high RDI were significantly associated with decreased mortality. These results can help identify potential risk factors and characterize the effect of chemotherapy dose modification strategies on mortality. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00520-019-04875-1) contains supplementary material, which is available to authorized users.