Steroid hormone receptors in the management of human breast cancer.

Recent insight into the mechanism of steroid hormone receptors in human breast cancer has led to new approaches in treatment strategy. Estrogen receptor (ER) has now replaced clinical criteria in the selection of patients for endocrine therapy. Patients whose tumors do not contain ER should not be subjected to hormonal manipulation. In addition, ER measured on the primary tumor has been found to be an independent prognostic factor for both recurrence and survival. Patients with ER negative primary tumors have a poorer prognosis. This information may be useful in the design and selection of therapy for future adjuvant clinical trials. In metastatic breast cancer, the absolute ER value may provide valuable information regarding endocrine responsiveness. In addition, the measurement of progesterone receptor (PgR) may provide additional insight for predicting with confidence those patients likely to respond.