PTEN-positive and phosphorylated-Akt-negative expression is a predictor of survival for patients with advanced endometrial carcinoma

PTEN and the PI3K/Akt pathway are involved in the development and/or progression of endometrial carcinoma. To clarify the impact of the pathway-related molecules on prognosis, we analyzed PTEN, phosphorylated-Akt (p-Akt), and Ki-67 expression by immunohistochemistry in 99 patients with advanced endometrial carcinoma. PTEN-negative or PTEN-mixed staining was found in 66% of tumors. Positive staining of p-Akt was found in 40% of tumors. Loss of PTEN expression (negative or mixed) was significantly associated with positive p-Akt expression. The patients with PTEN-positive and p-Akt-negative expression clearly showed a higher survival rate than patients in the other groups. Subsequent multivariate analysis revealed that the combination of PTEN/Akt expression was an independent prognostic factor. Examining the relationship between p-Akt expression and Ki-67 labeling index (LI), we found that negative p-Akt was related to a decrease in Ki-67 LI. Additionally, the patients with low Ki-67 LI, as determined by p-Akt-expression status, had a better prognosis. In the present study, we demonstrated that PTEN-positive and p-Akt-negative expression was a predictor of survival for patients with advanced endometrial carcinoma. This study suggests the clinical significance of PTEN and p-Akt expression analysis in treatment decisions for patients with advanced endometrial carcinoma.