Neutrophil-to-Lymphocyte Ratio Is Superior to Other Leukocyte-Based Ratios as a Prognostic Predictor in Non-Small Cell Lung Cancer Patients with Radiosurgically Treated Brain Metastases Under Immunotherapy or Targeted Therapy.

Abstract

To investigate predictive value of preradiosurgery leukocyte-based prognostic ratios in a selected cohort of non-small cell lung cancer (NSCLC) patients with radiosurgery-treated brain metastases (BM) and concomitant immunotherapy (IT) or targeted therapy (TT). We performed a retrospective analysis of 166 patients with NSCLC BM treated with Gamma Knife radiosurgery. Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio, and lymphocyte-to-monocyte ratio were assessed within 14 days before radiosurgery. In radiosurgically treated patients with NSCLC BM with concomitant IT or TT, estimated median survival after first Gamma Knife radiosurgery treatment was significantly longer in patients with NLR cutoff value <5 (P = 0.038). Consequently, the Cox regression model for NLR cutoff value groups revealed a significant hazard ratio of 1.519 (95% confidence interval 1.020-2.265, P = 0.040). In addition, each increase in NLR of 1 equaled an increase of 5.4% in risk of death (hazard ratio 1.054, 95% confidence interval 1.024-1.085, P < 0.001). After adjusting for sex, age, Karnofsky performance scale, and presence of extracranial metastases, NLR remained a significant and independent predictor for survival (hazard ratio 1.047, 95% confidence interval 1.017-1.078, P = 0.002). In contrast, platelet-to-lymphocyte ratio and lymphocyte-to-monocyte ratio did not exhibit the same predictive value among patients with radiosurgery-treated BM with concomitant IT or TT. In patients with NSCLC BM treated with radiosurgery with concomitant IT or TT, preradiosurgery NLR represents a simple prognostic predictor for survival and is superior to other leukocyte-based ratios. NLR may be relevant for clinical decision making, therapeutic evaluation, patient counseling, and appropriate stratification of future clinical trials among patients with radiosurgery-treated BM.