Nuclear and cytoplasmic estrogen receptors and progesterone receptors in breast cancer

Abstract

Tissues from 83 primary human breast carcinomas were investigated for cytoplasmic estrogen receptors, cytoplasmic progesterone receptors, and free and occupied nuclear estrogen receptors, and the relationship between the various receptor fractions was determined. The two most frequently observed receptor distributions were cytoplasmic estrogen receptors with free nuclear estrogen receptors, with or without occupied nuclear estrogen receptors, in the absence of progesterone receptors. Carcinomas with all receptors either negative or positive were found in about equal numbers and were the next most frequently encountered distribution. Another common combination was the presence of cytoplasmic estrogen receptors only, with none of the other measured receptors.