Analysis of Bcl-2, PTEN, p53, and Ki-67 expressions in endometrial cancer arising from endometrial polyp

Objective: To compare the expression of the proliferation marker Ki-67, the antiapoptotic protein Bcl-2, and the tumor suppressor genes p53 and PTEN between endometrial cancer arising from endometrial polyp and benign endometrial polyps. Materials and Methods: The study was performed retrospectively in 40 patients treated at the present institution between 2006-2011. A total of 20 cases that had endometrial cancer arising from endometrial polyp that met study criteria were included consecutively in the study. For each malign case, one case that had a benign endometrial polyp diagnosed at hysterectomy specimen was included in the study. Results: The Ki-67 score was significantly higher in endometrial cancer arising from endometrial polyp group in comparison to the benign polyps (p < 0.05). However, the Bcl-2 expression was significantly lower in the endometrial cancer arising from endometrial polyp when compared to the benign polyps (p < 0.05). PTEN and p53 expressions were not different between groups (p > 0.05). in patients with endometrial cancer, Ki-67, Bcl-2, PTEN, and p53 expressions were not different among histological type, stage, grade, myometrial invasion, polyp size, and lymphovascular space invasion, with an exception of p53. p53 expression was significantly increased in higher grade tumors (p < 0.05). Conclusion: The results of the present study indicate that there is an inhibition of apoptosis and a decrease in proliferation in benign endometrial polyps. Possibly, at carcinogenesis step of endometrial cancer developed from benign polyp, other additional mutations cause a reverse effect and they increase proliferation and prevent the apoptosis inhibition.