Interferon regulatory factor-1 expression in human uterine endometrial carcinoma

Objective. The objective was to investigate the expression of interferon regulatory factors 1 (IRF-1) in human uterine endometrial carcinoma. Methods. Formalin-fixed, paraffin-embedded, archival tissue specimens from 76 human endometrial carcinomas and stained with polyclonal anti-IRF-1 antibody, using immunohistochemistry, localization, and immunostaining, were evaluated quantitatively using the H score together with 30 normal endometrium and 16 postmenopausal endometrium. Results. The expression of IRF-1 was highest in normal endometrium, and decreased with the grade of endometrioid adenocarcinoma from grade 1 to grade 3. Postmenopausal endometrium was virtually unstained. Conclusions. Expression of IRF-1 is altered in human endometrioid adenocarcinoma compared with normal endometrium and postmenopausal endometrium. The loss of IRF-1 expression does not contradict with the tumor-suppressor function. The intensity of IRF-1 expression in each grade of endometrioid adenocarcinoma could be useful prognostic and therapeutic indicators. (C) 2003 Elsevier Inc. All rights reserved.