The prediction of hormonal dependency of mammary cancer.

Less than half of premenopausal patients with mammary cancer and even fewer postmenopausal patients have tumors that respond to endocrine ablation. The level of estrogen receptor protein (estrophilin) in the mammary cancer tissue provides an indication of the hormone dependency of the tumor and may be sued to predict the response to endocrine treatment when recurrent disease appears. Metastatic growths usually have a similar content. This is a report of an investigation of the estrophilin content of specimens of tumors from patients with metastatic and recurrent mammary cancer for correlation with their response to endocrine changes. Primary tumors were also studied for future clinical use if needed. The estrophilin was determined in specimens from 214 metastatic growths and 359 primary breast cancers. The uptake of estradiol in an in vitro system and the blocking effect of specific inhibitors provided a means of distinguishing between estrogen responsive tissues which contained receptor proteins and non-estrogen-responsive tissues which did not contain these receptors. Some form of endocrine manipulation was used in 82 patients. Of these, 69 had ablative therapy. Of the 69, significant receptor levels were present in 27 and 2/3 of them had remissions. Of the 42 with negative e strophilin determinations, none had a remission after ablation. Therefore, the absence of significant amounts of estrophilin in breast cancer tissue indicates that the patient has little chance of responding to endocrine manipulation and should be spared this method. In 16 others, hormonal additive treatment was used. Only 1 of 6 patients with negative determinations benefited temporarily from the additive hormone therapy. Discussion and questions by others followed presentation of this paper. Other hormones as possibly important were suggested. Combining chemotherapy with adrenalectomy was suggested. It was stated that some noncancerous breast tissues also contain estrogen binding proteins. Dr. Block answered questions and added comments. He stated that estrophilin is present in many tissues but in very low amounts. It is a quantitative difference that is important.