We chose age at diagnosis (cut off by 35 years old), BRCA mutation status, menopausal status, nuclear grade, ER status, PR status, HER2 status, FH of BC, ki67 index (cut off by 14% or 30%), subgroup of HR/HER2 status, adjuvant endocrine therapy and irradiation therapy as related risk factors for Cox univariate analysis (Table 6). Here, ESR1 is linked to breast cancer.