Histochemical analyses of steroid hormone receptors in breast and prostatic carcinoma

Histochemical analyses for estrogen (ER) and progesterone (PgR) receptors in breast cancer were statistically correlated with results of dextran-coated charcoal (DCC) and sucrose gradient assys. Correlation for ER was 91% of 363 cases, and for PgR 88% of 225 specimens. Breast cancer ER/PgR positivity by histochemistry correlated with a favorable clinical response to endocrine therapies in 72% of 25 cases, while ER/PgR negativity correlated with a lack of response in 96% of 22 cases with Stage IV disease. Nuclear ER/PgR correlated with a poor response to therapy in 8 and 12 patients. An in vitro technique to detect nuclear translocation of ER revealed two groups of ER positive cases, with 11 of 17 exhibiting translocation and 6 not displaying translocation. In positive carcinoma, 72% of 65 were positive for ER and/or androgen receptor. Comparison of specimens obtained without and with electrocautery revealed a preponderance of nuclear binding in the latter, suggesting heat-induced nuclear translocation of receptor. Coumestrol, a naturally fluorescent, entirely unaltered estrogen was also used for histochemical dectection of ER. Results correlated with ER by DCC in 87% of 61 breast cancers. Coumestrol was additionally used to visually observe receptor and nuclear translocation of ER in intact whole cells in culture.