Predictors of sentinel lymph node metastasis in cT1-2 cN0 breast cancer: A retrospective cohort study

This study aimed to identify independent predictors of sentinel lymph node (SLN) metastasis in clinically node-negative (cN0) breast cancer and evaluate the diagnostic accuracy of intraoperative frozen section (FS). A retrospective analysis was conducted on 72 female patients with early-stage (cT1-2 cN0) invasive breast cancer who underwent SLN biopsy. Clinical, pathological, and radiological parameters were evaluated. Univariate and multivariate logistic regression analyses were performed to determine independent predictors of metastasis. Intraoperative FS results were compared with definitive paraffin pathology. Definitive permanent paraffin section analysis confirmed SLN metastasis in 41.7% (n = 30) of patients. The false negative rate for intraoperative FS was 23.3%. Multivariate analysis identified lymphovascular invasion (LVI; OR = 8.22, P = .001) and elevated continuous progesterone receptor expression (OR = 1.02, P = .008) as significant independent predictors of initial SLN metastasis. Conversely, human epidermal growth factor receptor 2 positivity demonstrated a significant inverse relationship with nodal involvement (OR = 0.20, P = .010). Other clinicopathological parameters, including Ki-67, were not significantly associated. Our findings suggest that initial SLN metastasis may be primarily associated with the presence of LVI, elevated progesterone receptor expression, and human epidermal growth factor receptor 2 status. Preoperative identification of these specific markers could optimize risk stratification and support the strategic consideration of neoadjuvant systemic therapy to mitigate the diagnostic limitations of intraoperative staging.