Physiological and pharmacological effects of estrogens in breast cancer

Tumour cyclic AMP binding proteins and endocrine responsiveness in patients with inoperable breast cancer

“…Concentrations of ER were significantly higher in tumours from responding patients as compared with those from the nonresponding group (P< 10-4 These results show, as have others (Edwards et al, 1979;Leclercq & Heuson, 1979), that patients with tumours having a high concentration of ER are more likely to respond to endocrine therapy than those with ER-poor tumours. However, whilst a statistical difference in ER levels exists between responding and non-responding groups, this does not provide discrimination for individual patients.…”

Mammary Gland Neoplasia in Long-Term Rodent Studies

“…The three main natural estrogenic hormones synthesized by ovarian follicles are estradiol, estrone, and estriol. Estrogens are critically involved in mammary gland development and are also essential for eliciting a tumorigenic response with chemical or physical carcinogens (47,197). Estrogens act on mammary epithelial cells through three different mechanisms: a direct receptor-mediated effect, a mammary stroma-mediated effect, and an in vivo stimulation of pituitary PRL levels, which in turn, stimulates lobuloalveolar development in the mammary gland (67,76).…”

The Biology of Breast Tumor Progression: Acquisition of hormone independence and resistance to cytotoxic drugs

“…However, there are a few important exceptions. Experimental rodent tumors frequently exhibit considerable variations in intertumor growth characteristics (46), exhibit a well-differentiated morphology and a low metastatic potential (47). These tumors exhibit a rapid progression to hormone-independent growth (48, 49) and a complete initial dependence upon prolactin (47,50).…”