Comparison of estradiol receptor investigations and histochemical investigations on enzymes in human mammary cancers.

The best way to predict the responsiveness of human breast carcinomas to hormone therapy is to investigate the estradiol receptor-binding abilities of these tumors. This binding induces many hormone-regulated changes in the activities of several enzymes. Therefore, enzyme activities after short-term organ culture exposed to added hormones were tested to see whether a correlation of enzyme activities exists with estradiol receptor binding. The results from both the estradiol receptor investigations and histochemical investigations on enzymes revealed a high degree of conformity, which confirms the existence of such a correlation. However, for this reason histochemical investigations on enzymes cannot eliminate the discrepancy between the experimentally verified existence of estradiol receptor binding and the response of mammary tumors to hormone therapy, which is not higher than 50-60%.