Peroxidase activity and estradiol receptors in human breast cancer.

In order to establish the relation between peroxidase activity in human breast carcinoma and its estrogen-dependency, estradiol receptors and their peroxidase activities were determined by a very sensitive fluorimetric method in 61 carcinomas. The geometrical mean of peroxidase activity in the 34 estradiol receptor negative carcinomas, 12.8 mU/g tissue, was significantly higher (p less than 0.