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.