Expression of Cyclin D1 in Hyperplasia and Carcinoma of Endometrium and Its Correlation with Histologic Grade, Tumor Type, and Clinicopathological Features.

Endometrial carcinoma is often preceded by characteristic histopathologic lesions known as endometrial hyperplasia. Estrogen, p53, PTEN, and overexpression of cyclin D1 appear to be involved in the development of endometrial carcinogenesis.  We evaluated and compared the expression profile of cyclin D1 expressions in 50 endometrial samples submitted as either endometrial curetting ( = 34) or hysterectomy ( = 16) specimens, which were diagnosed as simple hyperplasia ( = 10), complex hyperplasia ( = 06), atypical hyperplasia ( = 04), and endometrial carcinoma ( = 20). Ten cases of normal proliferative and secretory endometrium were selected as controls. Breast cancer with known cyclin D1 expression was selected as a positive control in each immunohistochemistry run.  Cyclin D1 was significantly overexpressed in glands with complex hyperplasia and endometrial adenocarcinoma compared with proliferative or secretory endometrium and simple hyperplasia. A statistical difference was found in the extent of cyclin D1 positivity of simple hyperplasia and carcinoma of the endometrium ( < 0.005). No statistical difference was seen between complex hyperplasia and carcinoma and clinicopathologic parameters in endometrioid carcinomas. All cases of clear cell carcinoma and serous carcinoma showed cyclin D1 immunoreactivity. Significant statistical difference was seen between cyclin D1 expression and only one clinicopathologic parameter, i.e., menopausal status in endometrial carcinomas  Cyclin D1 over expression may be an early event in endometrial carcinogenesis and cyclin D1 over expression may be an informative biomarker to recognize subsets of endometrial lesions that may be precancerous and therefore amenable to surgical therapy.