Neutrophil to Lymphocyte Ratio as a Predictive Marker of Vestibular Schwannoma Growth

Objective: To examine the predictive value of neutrophil to lymphocyte ratio (NLR) for vestibular schwannoma (VS) growth. Study Design: Retrospective case-control study. Setting: Tertiary, referral center. Patients: Patients with sporadic VS and available NLR obtained within 1 year from the diagnosis were divided into two groups with growing or non-growing tumor. Patients with known conditions affecting NLR were excluded. Interventions: NLR and tumor growth as determined by linear measurements on serial magnetic resonance imaging. Main Outcome Measures: VS growth, demographic factors, and NLR were compared using multi-variant logistic regression and Receiver Operating Characteristic (ROC) curve analysis. Results: A total of 161 patients fulfilled the inclusion criteria, 79 with growing VS (men: women ratio = 43: 36, mean age, 61.8 years) and 82 with non-growing tumors (men: women ratio = 37: 45, mean age, 64.9 years). Mean NLR for the group with growing VS was 3.34 (SD [standard deviation] = 1.5) and 2.31 (SD = 0.76) for the group with non-growing VS (p = 0.001; 0.03 when adjusted for all parameters). The optimal cut-off point was NLR = 3.05 with positive predictive value 83.8% and 100% for NLR greater than 5.3. ROC analysis of the adjusted data for age, sex, and side, gave an area under the curve of 0.768, indicating NLR as a good independent predictive marker. Interestingly, the size of tumor was statistically significantly higher for the growing VS group (p = 0.001). Conclusion: Despite the low specificity of low NLR, our results indicate high NLR as a good predictive marker for VS growth. Confirmation by prospective studies will have a significant impact on patients' management.