Immunohistochemical study of cyclins D and E and cyclin dependent kinase (cdk) 2 and 4 in human endometrial carcinoma

We studied the immunolocalization of cyclins D1 and E and their corresponding partner cyclin dependent kinases (cdk), cdk4 and cdk2 in 39 cases of human endometrioid endometrial carcinoma and examined the correlations between the labeling indexes of the cyclins, cdks and clinicopathologic parameters and the clinical outcome of the patients. Cyclin D1 immunoreactivity was observed exclusively in the nuclei of tumor cells in 22/39 (56%) of the cases examined. Immunoreactivity for cyclin E, cdk2, and cdk4 was detected in carcinoma cells of 37/39 (95%), 39/39 and 36/39 cases, respectively. There were no significant correlations between the labeling indices of any of the parameters examined. Cyclins D1 and E labeling indices were not significantly correlated with any of the clinicopathologic parameters examined. However, there was a significant correlation between cdk2 labeling index and the histological grade of carcinoma (p < 0.0001), and a significant correlation (p = 0.015) was also detected between the cdk4 labeling index and pathologic stages. There was no significant difference in clinical outcome of the patients according to the cyclin and ckd4 immunostaining patterns. These results indicate that cdk2 and cdk4 overexpression may be involved in the development and/or progression of human endometrioid endometrial carcinoma.