Correlation between estrogen receptor levels and clinical response to ovariectomy in premenopausal women with advanced breast cancer.

From 1974 to 1980, according to a controlled clinical trial, 66 premenopausal women with advanced breast cancer underwent bilateral ovariectomy (BO). Of the hormonal parameters evaluated, the present study deals with estrogen receptors (ER). The relation between the presence or the absence of ER and clinical response was evaluated, without considering their concentration in neoplastic tissue. The response was evaluated in relation to threshold values of 5 fmol/mg protein (considered at the time of the study the cut-off value of negativity and positivity) and 10 fmol/mg protein (recently found to be a more accurate cut-off value). The results of BO in relation to different receptor status showed an analogous response. Furthermore, the higher the receptor concentration, the better the response to BO, especially when the concentration was higher than 25 fmol/mg protein.