Relationship between peroxidase activity and steroid receptors in human mammary tumors

The interrelationships between levels of estradiol receptors (ER) and estrogen-dependent proteins, peroxidase and progesterone receptors (PgR) were examined in 54 histologically proven primary breast tumors in Indian women. ER and PgR were determined by the agar gel electrophoresis and dextran coated charcoal methods, respectively. Peroxidase activity (PA) was estimated by the guaiacol method. Our results showed a lack of correlation between ER and PA as well as between concentrations of PgR and PA in the tumors. It was concluded from this preliminary investigation that, in addition to ER and PgR, estimation of PA does not contribute significantly to more accurate assessment of hormone dependence of human breast tumors.