Expression of p53, Bcl-2 and Bax in endometrial carcinoma, endometrial hyperplasia and normal endometrium: a histopathological study.

Our objective was to examine the expression rates of p53, Bcl-2 and Bax in endometrial carcinoma, endometrial hyperplasia and normal endometrium. A total of 94 endometrial frozen sections (carcinoma 48, hyperplasia 21, normal tissue 25) were examined immunohistochemically in terms of the expression rates of p53, Bcl-2 and Bax. All of the specimens in the non-malignant groups were positive for Bax, whereas this rate was 85.4% in the group with malignant specimens (p = .03). Conversely, p53 was expressed only in the cancerous group (77.1%, p < .001). The Bcl-2 expression rate was 54.2% in the cancer group, 76.2% in the group with hyperplasia and 60% in the group containing normal tissue (p = .23). Comparing to the non-malignant specimens, the mean Bcl-2/Bax were significantly higher in the malignant group. In conclusion, Bax under-expression, p53 over-expression and a high Bcl-2 to Bax ratio might be associated with endometrial carcinoma. Bcl-2, however, plays no significant role in this regard. Impact statement What is already known on this subject? The p53, Bcl-2 and Bax are the three major genes that regulate apoptosis. Some studies have suggested that these genes may play a role in the pathogenesis of endometrial carcinoma. The available reports, however, are old and inconclusive. What do the results of this study add? Comparing immunohistochemically obtained p53, the Bcl-2 and Bax expression rates between normal endometrial tissue, endometrial specimens with endometrial hyperplasia and specimens with carcinoma showed that Bax under-expression, p53 over-expression and a high Bcl-2 to Bax ratio were associated with malignancy. Using an up-to-date technique to examine the three major regulators of apoptosis at the same time, in a rather large sample size of both normal and abnormal endometrial tissue specimens simultaneously, are the major advantages of the present work. What are the implications of these findings for clinical practice and/or further research? According to our findings, the status of p53, Bcl-2 and Bax expression in the endometrial tissue can be used for risk stratification of endometrial carcinoma for both screening and preventive purposes.