Diagnostic and Prognostic Values of PTEN Expression in Functional and Pathological Endometrial Biopsies

Abstract

Background: Endometrial carcinoma is the most common gynecological malignancy in developed countries. About 80% of endometrial carcinomas are preceded by atypical endometrial hyperplasia. PTEN is a tumor suppressor gene involved in many vital intracellular biological processes. PTEN is altered in more than 45% of endometrial carcinomas. The aim of this study was to evaluate the value immunohistochemical expression of PTEN in normal, hyperplastic and neoplastic endometrial tissues. Methods: Ninety-two endometrial samples were enrolled in this study. They were classified into normal (n=6), hyperplastic (n=54) and neoplastic (n=32) endometrial tissues. Formalin-fixed and paraffin-embedded tissue blocks were prepared from each specimen. Tissue sections were immunohistochemically stained by anti-PTEN antibodies. Results: In our study; PTEN was strongly expressed in all normal and hyperplastic endometrial tissues without atypia. Staining intensity was decreased in atypical endometrial hyperplasia and endometrial carcinoma (p<0.0001). we also detected an inverse relationship between PTEN expression on one side and tumor grade (p=0.006), stage (p< 0.0001) and myometrial invasion (p=0.001) on the other side. Conclusions: Our study proved that immunohistochemical expression of PTEN is down-regulated in atypical hyperplastic and neoplastic endometrial tissues. Evaluation of PTEN expression can be useful as a screening method to detect the potentially precancerous hyperplastic lesions.

Phosphatase and Tensin Homolog Immunohistochemical Expression and Promoter Methylation Status in Endometrioid Endometrial Carcinoma and Its Precursor Lesions

“…However, Sarmadi et al [ 8 ] and Sal et al [ 22 ] reported a loss of PTEN expression slightly less (52% and 61%) in cases of EEC than in the present study. Although Allithy et al [ 19 ] found that none of the EEC showed strong PTEN expression, a finding similar to our study. The variation in the loss of PTEN expression in various studies could be due to various stages of disease progression, different age groups, variability in the sampling, and the use of different types of antibodies (polyclonal or monoclonal).…”

“…Erkanli et al [ 18 ] reported a less homogenous pattern with a few scattered PTEN null glands interposed among PTEN-positive glands in proliferative endometrium. However, other studies did not observe a loss of PTEN expression in hyperplasia without atypia [ 18 , 19 ]. Aguilar et al [ 20 ] observed aberrant PTEN expression in 50.5% of endometrial hyperplasia cases.…”

“…Aguilar et al [ 20 ] observed aberrant PTEN expression in 50.5% of endometrial hyperplasia cases. Allithy et al [ 19 ] did not observe a loss of PTEN expression in hyperplasia without atypia, while most atypical hyperplasia (27/29, 93%) showed mild to moderate loss of PTEN expression. Loss of PTEN immunoreactivity was found in 25% (2/8) of cases of hyperplasia with atypia by Sarmadi et al [ 8 ].…”