During 2,502,695 person-years of follow-up from 1989 to 2013, 3966 invasive breast cancers occurred (n = 2373 ER+; n = 585 ER-; n = 2074 ER+/PR+; n = 513 ER−/PR-; n = 285 ER+/PR-; n = 293 ER−/PR−/HER2-). Here, ESR1 is linked to invasive breast carcinoma.