Clinical relevance of Elf-1 overexpression in endometrial carcinoma

Abstract Objectives Elf-1 is a member of the Ets transcription factor family that regulates the genes involved in cellular growth and differentiation. Enhanced expression of Elf-1 has been reported in prostate cancer, breast cancer, and osteosarcoma. Methods To elucidate the involvement of Elf-1 in endometrial carcinogenesis, we analyzed serial frozen tissue sections from 31 patients with endometrial carcinoma and 20 patients with normal endometria for Elf-1 protein expression, using fluorescent immunohistochemistry. We analyzed the relationship between the percentages of Elf-1-stained cells and patient characteristics, including clinical stage, histological grade, presence of invasion to greater than one-half the myometrium, clinical outcome, and survival rate. Results Elf-1 was weakly detected in some normal endometria in the proliferative phase (0–18.9%) and other normal endometria in the secretory phase (0–28.5%). There was, however, abundant Elf-1 immunoreactivity in the nucleus of the endometrial carcinoma cells along with a little cytoplasmic staining. Scoring on the basis of the percentage of nuclear-positive cells indicated that nuclear Elf-1 expression was significantly associated with PCNA-labeling index, clinical stage, histological grade, the presence of invasion to greater than one-half the myometrium, and clinical outcome ( P P Conclusions Our results demonstrate that Elf-1 expression in endometrial carcinoma correlates with the malignant potential of this tumor.