The “Multivariate logistic regression analysis of risk factors for sentinel lymph node metastasis” and the “ROC curve of independent risk factors for sentinel lymph node metastasis in breast cancer” sections indicate that age, tumor diameter, BI-RADS score, pathological type, CK5/6, EGFR, CK19, TP53, and BRAC1/2 are independent risk factors affecting sentinel lymph node metastasis of breast cancer, which may provide some guidance on sentinel lymph node metastasis. This evidence concerns the gene KRT19 and breast cancer.