Significance of tissue estrogen receptors in the strategy of breast cancer treatment.

Using evidences of estrogen receptors in mammary tumor tissues it was tried 1. to find substances which inhibit the tumor growth by their binding to the estrogen receptors; 2. to predict responsiveness to endocrine therapy; and 3. to find a definition of an improved therapeutic strategy in breast cancer. There is a continuously increasing rate of receptor positive tumors, caused by an improved technique of determination and tissue handling. Estrogen receptors were detected in 73 per cent of all primary mammary tumors and 58 per cent of metastatic tumors respectively. As new therapeutic substances nafoxidine and Estracyt were tested in controlled clinical trials. To get exact data about hormonal sensitivity further quantitative investigations of receptor activities of mammary tumors and their therapeutical responsiveness have to be done. As a new step in the strategy of breast cancer therapy based on receptor determinations a combined therapy with hormones and cytotoxic chemotherapeutics has to be checked in clinical trials in uture.