Steroid receptors in human breast cancer.

The measurement of cytoplasmic estrogen receptor in tumors from patients with breast cancer is now well established. Potential uses include prognosis of early recurrence following mastectomy, stratifying patients for adjuvant therapies, and selecting or rejecting endocrine therapy in advanced breast cancer. The use of progesterone receptor measurements to improve our selection process has a good theoretical basis, and early reports now emerging indicate that the presence of both estrogen and progesterone receptor in a breast tumor predicts a high response rate to endocrine therapy. Further work in this area is required, however, since patients with estrogen receptor but not progesterone receptor still have an appreciable response rate.