Cyclin D1 expression in high-grade endometrial carcinomas--association with histologic subtype.

Overview

abstract

Endometrial endometrioid adenocarcinoma (EC) and serous carcinoma (ESC) are associated with different epidemiologic risk factors, precursor lesions, morphology, and survival outcomes. They also possess distinct molecular profiles. We investigated the expression of cyclin D1, a member of the G1 cyclin family that regulates the G1/S transition in the cell cycle, and estrogen and progesterone receptors (ERs and PRs, respectively) in a group of ECs and ESCs matched for histological grade. We also sought to correlate the expression of cyclin D1 with ER and PR because cyclin D1 has been reported to stimulate transcription of ER- and PR-regulated genes (1,2). We hypothesize that cyclin D1 expression covaries with histologic subtype and is related to the expression of ER and PR. Twenty ESCs and 21 ECs were examined histologically and evaluated immunohistochemically for cyclin D1, ER, and PR using commercially available monoclonal antibodies in archival, formalin-fixed, and paraffin-embedded tissue. Three ESCs (15%) and 10 ECs (48%) expressed cyclin D1 (p = 0.02). Twelve ESCs (60%) and 16 ECs (76%) expressed ER, which is not significantly different. ER-positive ECs were significantly more likely to express cyclin D1 compared with ER-positive ESCs (p = 0.03), but a relationship between cyclin D1 and ER expression in EC was not found. We also did not find a significant relationship between cyclin D1 and PR expression. Therefore, cyclin D1 expression in poorly differentiated endometrial carcinomas is associated with endometrioid histology. This is consistent with pathobiologic divergence in poorly differentiated endometrial carcinomas.