前立腺癌におけるエストロゲンレセプターの免疫組織学的検索 ： ホルモン療法及び細胞増殖能との関連

Abstract

Immunohistochemical detection of estrogen receptor (ER) in paraffin sections of human benign prostatic hypertrophy (BPH) and prostatic carcinoma (PC) is examined. H 222 monoclonal antibody (ER-ICA kit) against ER was used in 30 cases of BPH and 50 cases of PC. All BPH cases were positive for ER, whereas only 48% of malignant cases (24/50) reacted with H 222 antibody. Positive rates for well-, moderately-, and poorly-differentiated adenocarcinomas were 86%, 64%, and 11%, respectively, indicating correlation between the histological degree of differentiation and positive reaction for ER. Moreover, 15 cases of PC after estrogen treatment were also examined and the histological effect on hormone therapy was investigated. Effects of estrogen treatment were poor when cases were negative staining for ER before therapy. It is suggested that ER immunohistochemistry has a new prognostic value in PC in terms of the response to hormone therapy. In addition, proliferating cell nuclear antigen (PCNA) and argyrophilic staining of the nucleolar organizer region (AgNOR) were examined to determine whether ER status related to cell kinetics. PCNA index and AgNOR score in poorly-differentiated PC were higher than those in more differentiated PC. ER status in PC seems to be correlated to the cell proliferative index.