Estrogen receptors β1 and β2 are associated with distinct responses of estrogen receptor α-positive breast carcinoma to adjuvant endocrine therapy.

•We studied relapse of ERα+ breast carcinoma treated with adjuvant endocrine therapy.•We determined the expression status of ERβ1 and ERβ2 using immunohistochemistry.•High ERβ1 expression predicted lower risk of recurrence within 4 years from surgery.•High ERβ2 expression predicted higher risk of recurrence after 4 years from surgery.•The expression status of ERβ1 and ERβ2 may aid making adjuvant therapy choices.