The Prognostic Value of the Pretreatment Neutrophil/Lymphocyte Ratio in Patients with Glioblastoma Multiforme Brain Tumors: A Retrospective Cohort Study of Patients Treated with Combined Modality Surgery, Radiation Therapy, and Temozolomide Chemotherapy

Background: Recent studies have shown that the peripheral blood pretreatment neutrophil/lymphocyte ratio (NLR) is a prognostic measure in various cancers. The few studies evaluating NLR in glioblastoma multiforme (GBM) patients yielded inconsistent results.

Objectives: The primary objective of our study was to test the ability of pretreatment NLR to predict the overall survival (OS) and progression-free survival (PFS) of patients with GBM treated by combined modality therapy (surgery, radiation, and temozolomide chemotherapy). A secondary objective was to evaluate the toxicity of the combined modality protocol in a consecutive series of patients treated in our center, in the context of a real-world universal health-care setting.

Methods: We analyzed 89 patients with GBM in a retrospective cohort analysis who were treated in Soroka University Medical Center's Oncology Department between the years 2005-2016. We analyzed NLR as a dichotomous variable at 3 cut-off points, 2.5, 3 and 4, as a predictor of OS and PFS. Methylation status of the O6-methylguanine-DNA methyltransferase (MGMT) promoter was not determined.

Results: No significant correlation was found between NLR and either OS or PFS. Factors that predicted a shorter OS were age and extent of surgery. Patients over 70 years of age had a statistically significant shorter OS, 12.5 months (95% CI: 10.4-14.5 months) versus 17.6 months (95% CI: 14.2-21.1 months) in those 70 years of age and younger (p = 0.004). The OS of patients undergoing partial resection (12.7 months 95% CI: 8.3-17.1 months) or biopsy only (9.3 months 95% CI: 7.8-24.6 months), was significantly shorter than that of patients undergoing total resection (18.9 months, 95% CI: 11.8-26.0 months; p = 0.035). There were no treatment-related deaths. The most common grade III-IV toxicities were thrombocytopenia, 12.4%, and fatigue, 13.5%.

Conclusions: In our cohort of GBM patients treated with combined modality therapy, pretreatment NLR was not prognostic. Toxicity of treatment was acceptable. Investigation of the NLR with larger groups of patients selected by MGMT status is warranted.