Prognostic role of pretreatment neutrophil to lymphocyte ratio in breast cancer patients: A meta-analysis

BACKGROUND: Inflammation and cancer are closely related to each other. As a parameter that can reflect inflammation and host immune reaction, elevated blood neutrophil to lymphocyte ratio (NLR) has been confirmed to be correlated with poor prognosis in a variety of cancers. However, this remains controversial in breast cancer. Thus, we performed this updated meta-analysis to further clarify whether high NLR could be a predictor of survival in breast cancer patients. METHODS: We searched on PubMed Database and Cochrane Library. Overall survival (OS), disease-free survival (DFS), and cancer-specific survival were used as outcome events, and hazard ratio (HR) was chosen as the parameter to evaluate the correlation. RESULT: Eighteen eligible studies were involved in this meta-analysis. The synthesized analysis demonstrated that elevated NLR was associated with poor DFS [HR = 1.72, 95% confidence interval (95% CI) = 1.30–2.27], OS (HR = 1.87, 95% CI = 1.41–2.48), and cancer-specific survival (HR = 2.09, 95% CI = 1.04–4.21). The correlation was stronger in triple-negative breast cancer (TNBC) (OS: HR = 2.58, 95% CI = 1.63–4.06; DFS: HR = 3.51, 95% CI = 1.97–6.24). CONCLUSION: Higher NLR was correlated to poor prognosis of breast cancer patients. As a clinical parameter that we can easily obtain, NLR might be a potential predictor in patients’ survival to assist with physicians’ treatment decisions.