Association of Pretreatment ANR and IronMLR With Pathological Response Following Neoadjuvant Chemotherapy in Breast Cancer.

BACKGROUND: Reliable biomarkers for predicting response to neoadjuvant chemotherapy (NAC) in breast cancer remain limited. This study evaluated the association of pretreatment Albumin-to-Neutrophil Ratio (ANR) and IronMLR with pathological response following NAC. METHODS: This retrospective study included 71 patients with breast cancer treated with NAC. Pretreatment inflammatory indices were calculated from routine blood samples obtained before treatment initiation. ANR and IronMLR were compared across pathological response groups. Receiver operating characteristic (ROC) analysis was performed to evaluate predictive performance. RESULTS: The mean age was 53.9±10.6 years, and pathological complete response (pCR) was achieved in 30 patients (42.3%). ANR was not significantly associated with pathological response (p=0.121). In contrast, IronMLR levels differed significantly among complete responders, partial responders, and non-responders (p<0.001). ROC analysis demonstrated favorable discriminatory performance of IronMLR for predicting treatment response, with an area under the curve of 0.909 (95% CI, 0.832-0.986; p<0.001). An IronMLR cut-off value of 175.40 yielded 77.4% sensitivity and 77.8% specificity. Patients with IronMLR ≥175.40 exhibited significantly higher response rates than those with lower values (96.0% vs 66.7%, p=0.001). CONCLUSION: Pretreatment IronMLR was significantly associated with pathological response following NAC in patients with breast cancer, whereas ANR showed no significant association. Given its simplicity and accessibility, IronMLR may represent a potentially useful biomarker for treatment stratification. Further prospective multicenter studies are warranted to validate these findings.