Preoperative systemic inflammatory markers (SII, PLR, MRR) as potential indicators of axillary lymph node metastasis in early-stage breast cancer

BACKGROUND: Axillary lymph node metastasis (ALNM) in a pivotal prognostic indicator in breast cancer. Systemic Immune-Inflammation Index (SII), Platelet-to-Lymphocyte Ratio (PLR), and Monocyte-to-Red blood cell Ratio (MRR), have emerged as potential predictive markers for ALNM given their ability to reflect host inflammatory and immune responses within the tumor microenvironment. METHODS: We retrospectively analyzed 293 data of patients with T1-T2 stage breast cancer treated between 2019 and 2024. Preoperative peripheral blood samples were collected to calculate SII, PLR, and MRR. Axillary lymph node status was determined through postoperative pathological examination. Receiver operating characteristic (ROC) curve analysis was used to establish optimal cut-off values for each index. Associations between inflammatory markers and ALNM were evaluated using univariate and multivariate logistic regression models, adjusting for age, tumor stage, molecular subtype, and other relevant clinicopathological factors. RESULTS: ALNM was present in 121 patients (41.3%). Compared with patients without ALNM, those with ALNM had significantly higher PLR (p = 0.015), SII (p = 0.018), lower MRR values (p = 0.035). Multivariate analysis revealed that low PLR (vs. high; OR = 0.447), low SII (vs. high; OR = 0.323), and low MRR (vs. high; OR = 1.862) were independently associated with ALNM risk. CONCLUSION: Preoperative SII, PLR, and MRR show modest discriminatory ability in early-stage breast cancer and may serve as supportive tools for risk stratification.