Comparison of Estradiol Receptor Investigations and Histochemical Investigations on Enzymes in Human Mammary Cancers 1,2

ABSTRACT-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 activi-ties 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 re-vealed 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 re-ceptor binding and the response of mammary tumors to hormone therapy, which is not higher than 50-60%.-JNCI 1981; 67