Estrogen receptors in human breast cancer detected by the fluorescent estradiol histochemical and dextran coated charcoal techniques.
Surgical specimens from 60 Japanese women with breast cancer were studied histochemically to detect estrogen receptors (ER). Forty-six were analyzed in a double blind study designed to compare the histochemical method using fluorescent estradiol conjugate for detection of ER (FITC method) with findings in case of the currently employed dextran coated charcoal (DCC method) techniques. The ER test was positive in 39 (65 percent) of the 60 cases studied by FITC method. Of the 46 cases analysed in a double blind study, 41 (89.8 percent) showed the same results. Of the 5 with inconsistent test results, 2 showed positive DCC and negative FITC, and 3, negative DCC and positive FITC. According to the histologic type, the FITC method demonstrated a low positive ER response rate in scirrhous cases (57 per cent), whereas the positive rate was 67 percent among papillotubular-type cases and 65 percent among medullary tubular-type cases. In relation to menstrual status, the positive rates were 68 percent and 64 percent among premenopausal and postmenopausal women, respectively. However, in relation to tumor size, no difference was noted in the positive response rate by either method. Therefore, both the DCC and FITC methods are clinically useful to determine the indications for hormone therapy.