The clinical value of the combined detection of circulating low ⁃ density neutrophils and inflammatory markers in breast cancer with lymph node metastasis

BACKGROUND: Breast cancer (BC) is the most prevalent cancer in women globally, with axillary lymph node metastasis (LNM) and distant metastasis being key prognostic factors linked to survival. Circulating low-density neutrophils (LDNs) in cancer patients are associated with tumor-supportive role. This study assessed the clinical relevance of combining circulating LDNs with hematological indicators in BC patients with LNM. METHODS: Peripheral blood samples from 184 BC patients were analyzed using flow cytometry to measure the LDNs levels. Lasso logistic regression was used for variable selection, and univariate and multivariate logistic regression identified independent risk factors. A predictive nomogram was developed and validated with an external cohort. RESULTS: LDNs were elevated in BC patients, especially those with LNM. Seven variables-LDNs, CEA, CA153, PLR, SIRI, NMLR, and NHR-were identified for further analysis. Multivariate logistic regression identified five of these as independent risk factors for LNM: LDNs (OR = 2.307, P = 0.032), CEA (OR = 4.027, P < 0.001), CA153 (OR = 2.440, P = 0.016), PLR (OR = 2.563, P = 0.014), and SIRI (OR = 4.617, P = 0.003). The nomogram model based on these factors demonstrated good predictive performance with an optimism-corrected C-statistic of 0.780, consistent in the external validation set (AUC = 0.762). The calibration curve confirmed good clinical applicability. CONCLUSION: This study suggests circulating LDNs levels may be potential biomarkers for BC progression, and a nomogram combing LDNs with other hematological indicators shows potential for identifying patients with LNM.