Alteration of the K-Ras Gene Expression in Atypical and Nonatypical Hyperplastic Endometrium

Background: Endometrial cancer is the most common gynecologic malignancy that has often proceeded by a premalignant phase. Modern molecular and immunostaining methods for precancerous lesions diagnosis have been expanded. One of the genetic alternations in the endometrial cancer carcinogenesis is the mutational activation of the K-ras oncogene. K-ras mutation has recognized to occur at an early stage of neoplastic progression in the endometrium. The purpose of this study is to investigate the expression pattern of K-ras gene in atypical and nonatypical hyperplastic endometrium.

Methods: In a prospective study in the referral gynecologic hospital in Tehran, immunohistochemical evaluation of K-ras has performed on 72 consecutive specimens in two following groups: endometrial hyperplasia without atypia (n: 36), and endometrial hyperplasia with atypia (n: 36). Staining of cells has evaluated in arbitrary quantitative methods in regards to both slides area staining and intensity of color reaction.

Results: K-ras immunoreactivity has seen in 3/36 (8.3%) cases of non-atypical hyperplasia and in 2/36 (5.6%) cases of atypical hyperplasia (P: 0.64).

Conclusion: We have not establish any significant differences in K-ras expression between the atypical and nonatypical hyperplastic endometrium, and our data has supported this view that K-ras mutation is a very rare event in human endometrial carcinogenesis.