Abstract
PURPOSE: We investigated the treatment response and prognosis using the neutrophil-to-lymphocyte ratio (NLR) and standardized uptake value (SUV) of (18)F-fluorodeoxyglucose positron emission tomography ((18)F-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 underwent (18)F-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.