Elevated Preoperative Neutrophil-to-lymphocyte Ratio As a Predictor of Worse Survival After Resection in Patients with Brain Metastasis

OBJECTIVE The median postoperative survival duration of patients with brain metastases who undergo tumor resection is 12 months. Most of these patients die of systemic metastases or the progression of primary cancer but not brain metastases. The criteria for indicating resection are still controversial. Systemic assessment is restricted, especially in patients who need emergent management for their large-size or life-threatening brain metastases. The neutrophil-to-lymphocyte ratio (NLR) is reported to correlate with survival time or progression-free survival in patients with various cancers. However, NLR has not been assessed in patients with brain metastases. The impact of NLR on the survival data of patients who had undergone resection of brain metastases was retrospectively analyzed. METHODS The clinical records of patients who underwent resection of brain metastases at Shizuoka Cancer Center between May 2007 and January 2015 were retrospectively analyzed. NLR was calculated by using the data obtained from the latest examination before resection and before the administration of steroid therapy. Kaplan-Meier curves were used for the assessment of overall survival (OS). RESULTS Of the 105 patients included, 67 patients were male. The median age of the patients was 63 years (range 36-90 years). The primary cancers were lung, colon, breast, uterus, and other cancers in 48, 19, 10, 8, and 20 patients, respectively. The postresection median survival duration was 12 months (range 1-91 months) for the entire series. The optimum NLR threshold value was identified as 5. A significant difference in the median OS was found: 14 months for 82 patients with an NLR < 5 versus 5 months for 23 patients with an NLR ≥ 5 (p = 0.001). CONCLUSIONS In this study, an elevated preoperative NLR is a predictor of worse survival after resection for brain metastases. NLR is a simple, systemic marker and can be used in clinical settings for decision making regarding resection in patients with brain metastases.