Optimal Cutoff for Neutrophil-to-Lymphocyte Ratio as a Tool for Pre-Chemotherapy Prognosis Stratification of Breast Cancer Patients

Introduction: The neutrophil-to-lymphocyte ratio (NLR) is an established inflammatory marker in cancerpatients. The optimal cut-off as an independent prognostic factor for breast cancer (BC) progression in patients undergoing chemotherapy remains debatable, hindering the effective stratification. This study explored the optimal NLR cut-off by comparing various thresholds and assessing their effectiveness in stratifying BC patients according to prognosis. Methods: Demographic, clinical, and cancer-specific data on forty-two BC patients were recorded, including complete blood counts before and after two cycles of chemotherapy. Receiver operating characteristic curve assessed discriminatory performance. Diagnostic metrics and Youden’s J index were calculated and McNemar’s test was used to compare baseline NLR cutoffs of 2.5, 3.0, and 3.5. Kaplan-Meier curves assessed the relationship between various NLR cut-offs and other cancer prognostic markers. Results: The three NLR cutoffs demonstrated distinct diagnostic metrics and Youden’s J index values (p < 0.001), with the 3.0 cutoff providing the most balanced performance. Patients with pre-chemotherapy NLR > 3.0 were predicted to develop advanced stage BC more rapidly compared to those with pre-chemotherapy NLR < 3.0. Conclusion: We believe that a more stringent NLR cutoff of 3.0 is the most suitable predictor of prognosis in BC patients based on the ranges evaluated in literature.