Effects of Chemotherapy Regimen and Radiation Modality on Hematologic Toxicities in Patients Receiving Definitive Platinum-based Doublet Chemoradiation for Non-Small Cell Lung Cancer

Objectives: Predictors of acute hematologic toxicities during definitive chemoradiation for non-small cell lung cancer (NSCLC) are incompletely defined. Materials and Methods: We retrospectively analyzed 604 patients treated with definitive platinum-based doublet chemoradiation therapy for stage III NSCLC. The outcome of interest was grade >= 3 acute hematologic toxicities, specifically white blood cell, hemoglobin, platelet, neutrophil, and lymphocyte decrease during chemoradiation therapy. We assessed the association between any grade >= 3 acute hematologic toxicity with patient demographic, disease, radiation factors (specifically modality and dose), and chemotherapy agents via stepwise multivariate logistic regression. Survival was compared via log-rank and univariate Cox regression analyses. Results: There was no significant association between radiation modality and any hematologic toxicity on multivariate analysis. However, use of etoposide was found to be significantly associated with white blood cell, platelet, and neutrophil decrease compared with paclitaxel and docetaxel (all P < 0.05). No differences were found between platinum agents. Overall survival (OS) and event-free survival (EFS) were significantly worse in patients who experienced grade >= 3 hemoglobin (OS: hazard ratio [HR] = 1.5; 95% confidence interval [CI], 1.05-2.26; P = 0.03, EFS: HR= 1.7; 95% CI, 1.2-2.4; P = 0.0032) and lymphocyte (OS: HR= 1.5; 95% CI, 1.1-2.1; P = 0.01, EFS: HR= 1.4; 95% CI, 1.1-1.9; P = 0.02) decreases. Conclusions: Chemotherapy identity, specifically the nonplatinum agent, was significantly associated with grade >= 3 hematologic toxicities, whereas radiation modality was not.