Neutrophil-lymphocyte ratio dynamics during concurrent chemo-radiotherapy for glioblastoma is an independent predictor for overall survival

Elevated neutrophil-lymphocyte ratio (NLR) may predict worse outcomes in cancer, including glioblastoma (GBM). This study assessed whether change in NLR during focal radiotherapy and concomitant temozolomide (RT-TMZ) provides further prognostic information. This was a retrospective review of patients treated with RT-TMZ for histologically confirmed GBM from January 2004 to September 2010. Variables assessed included age, ECOG performance status (PS), dexamethasone use and extent of surgery. Hematological results were collected at baseline, during and 4 weeks post RT-TMZ. Kaplan-Meier method was used to calculate overall survival (OS). Multivariable analysis (MVA) assessed for joint effect of covariates on OS and Pearson Correlation Coefficients assessed for association between dexamethasone dose and NLR change. With a median age of 55 (range 18-70), 369 patients were included. Median follow up was 15.1 month (range 1.6-134.6). The OS was 66.1% (95% CI 61.2-70.6) and 31.4 (95% CI 26.8-36.1) at 1 and 2 years, respectively. On univariate analysis, both decrease in NLR post RT-TMZ (HR 0.641, p < 0.0001) and baseline NLR < 7.5 (HR 0.628, p < 0.0001) were associated with longer OS. On MVA decrease in NLR (HR 0.727, 95% CI 0.578-0.915), age (HR 1.025, 95% CI 1.012-1.038), baseline neutrophil (< 8) (HR 0.689, 95% CI 0.532-0.891), total TMZ cycles (HR 0.89, 95% CI 0.867-0.913) and PS (HR 0.476, 95% CI 0.332-0.683) were independent predictors of OS. These findings suggest that a decrease in NLR during RT-TMZ, accounting for known prognostic factors, is an independent prognostic factor for survival in GBM.