Hormone Receptors and Breast Cancer

The hormone dependency of human breast cancer has been known since 1896, when Beatson¹ reported regression of inoperable primary tumors after ovariectomy in two premenopausal women. It is now well established that approximately one third of human breast carcinomas are responsive to hormones and will regress after a variety of hormonal manipulations. Until recently, there was no biochemical test that could reliably identify women who were harboring endocrine-dependent neoplasms and were thus likely to benefit from hormonal therapy. In 1971 Jensen et al.² first reported that measurement of estrogen receptors in a tumor-biopsy specimen was useful in predicting the response.