ERBB2 and neoplasm: A web-based calculator was developed based on the optimal model to facilitate clinical application.<h4>Results</h4>Univariate logistic regression identified higher tumor grade, advanced T/N stage, advanced clinical stage, and PR positivity as risk factors, whereas radiotherapy, chemotherapy, surgery, HR + /HER2- subtype, and unilateral tumors served as protective factors (<i>P</i> < 0.001).