The relative importance of estrogen receptor analysis as a prognostic factor for recurrence or response to chemotherapy in women with breast cancer.

The value of estrogen receptor (ER) analysis in primary breast cancer samples as a potential prognostic factor was examined in three clinical situations: time to recurrence in patients with no therapy after mastectomy, failure of patients receiving adjuvant therapy, and response of advanced disease patients to cytotoxic chemotherapy. Other prognostic factors analyzed were menopausal and nodal status. In none of these clinical settings were we able to demonstrate the usefulness of ER status as a prognosticator of the disease course or its response to therapy.