Various tools are used to estimate prognosis based on clinical and pathological factors, including age, tumour size, grade, nodal status, oestrogen receptor (ER) status, human epidermal growth factor receptor 2 (HER2) status, Ki67 status, menopausal status, comorbidities, frailty, mode of detection and generation of chemotherapy regimen. This evidence concerns the gene ERBB2 and neoplasm.