Estradiol and Progesterone in Human Breast Cancer Cytosols and Their Relationship to Receptor Incidence

Abstract

Plasma and breast cancer cytosol estradiol and progesterone levels were determined in pre and postmenopausal women and correlated with tumor estrogen and progesterone receptor incidence and content. There was no statistical correlation between plasma estradiol levels and estrogen or progesterone receptor incidence or content in premenopausal patients. Similarly, no correlation was apparent between plasma estradiol and progesterone levels, and tumor cytosol steroid concentration in either pre or postmenopausal women. In contrast to these observations, a significant inverse relationship developed between plasma progesterone levels and progesterone receptor incidence in premenopausal patients. An increase in tumor progesterone concentration in pre and postmenopausal patients was also significantly, and inversely related to receptor incidence. Our observations suggest that an increase in plasma progesterone and a decrease in tumor estrogen: progesterone ratio is significantly correlated with a decrease in estrogen and progesterone receptor incidence in pre- and postmenopausal patients.