Hormones and breast cancer.

The study of steroid hormone receptors in human breast cancer provides insight into tumor biology and forms the rationale for many therapeutic modalities. Clinical assays for estrogen and progesterone receptors improve the selection of patients who may benefit from hormonal therapy. In addition, receptor content in breast cancer tissue is useful for determining prognosis. Together with other new prognostic factors, hormone receptors help to distinguish among patients with primary breast cancer who are at risk for early recurrence.