Prognostic Value of Neutrophil-to-Lymphocyte Ratio and Early Standardized Uptake Value Reduction in Patients With Breast Cancer Receiving Neoadjuvant Chemotherapy

Purpose: We investigated the treatment response and prognosis using the neutrophil-to-lymphocyte ratio (NLR) and standardized uptake value (SUV) of¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET) in neoadjuvant settings. Methods: Baseline NLR and maximum SUV (SUV_max) were retrospectively analyzed in 273 females with breast cancer who received neoadjuvant chemotherapy followed by surgery. Of these, 101 patients underwent¹⁸F-FDG PET after 3–4 neoadjuvant chemotherapy cycles, which allowed the measurement of ΔSUV_max, an early reduction in SUV_max. NLR and early SUV_max reduction (ΔSUV_max) were classified as low and high, respectively, relative to the median values. Results: The mean NLR was lower, and the mean ΔSUV_max was higher in patients with pathologic complete response (pCR) than in those with residual tumors. The ΔSUV_max was an independent variable associated with pCR. Furthermore, the high NLR group had poor recurrence-free survival (RFS) and overall survival. Among patients with ΔSUV_max data, high NLR (adjusted hazard ratio, 2.82; 95% confidence intervals [CI], 1.26–6.28; P = 0.016) and low ΔSUV_max (adjusted hazard ratio, 2.39; 95% CI, 1.07–5.34; P = 0.037) were independent prognostic factors for poor RFS. The categorization of the patients into four groups according to the combination of NLR and ΔSUV_max showed that patients with high NLR and low ΔSUV_max had significantly poorer RFS. Conclusion: Baseline NLR and ΔSUV_max were significantly associated with the prognosis of patients with breast cancer who received neoadjuvant chemotherapy. These results suggest that metabolic non-responders with defective immune systems have worse survival outcomes.