The expression of nuclear estrogen receptor and its relation to cytoplasmic estrogen receptor in breast cancer]

Sixty specimens of breast cancer were assayed with ER-monoclonal antibody by immunocytochemical staining. Twenty-nine (48.33%) were nuclear estrogen receptor positive (ERn+). The number of ERn+ cancer cells decreased in the following sequence: mucinous carcinoma, invasive lobular carcinoma, invasive ductal carcinoma, and papillary adenocarcinoma. Two apocrine carcinomas were ERn-. ERn+ rate was higher in patients over 60 years of age (P less than 0.05). The amount of ERn+ cells was much greater in cancer cells than in the surrounding benign epithelial cells. This phenomenon may indicate that malignant cells are more hormone-dependent than benign cells. The results of immunocytochemical staining and steroid binding assay were compared. By immunocytochemical staining, twenty-four of fifty-seven cases (42.11%) were ERn+ and ERc+. Sixteen cases (28.07%) were ERn- and ERc-. This study showed that in a number of breast cancers ERs were positive in both cytoplasms and nuclei and the concordant rate was 70.18%. In the remaining cases 13 (22.81%), ERs were positive in the cytoplasm, and in 4 cases (7.02%) positive in nuclei only. Additionally, fifty-two out of 60 cases were assayed by 3H-estradiol and 3H-R5020 by means of steroid binding assay. Twenty-seven cases of them (51.92%) showed ERc+ and PRc+, and seventeen cases (32.69%) were ERc- and PRc-. Their correspondent rate was 84.61%.