Bcl-2 and Ki67 expression in endometrial polyps in postmenopausal women and their association with obesity
Abstract Background: Obesity is a global problem and is associated with numerous diseases, including endometrial disorders in postmenopausal women, such as adenocarcinoma, hyperplasias and endometrial polyps, and with risk of malignant transformation of these structures. We aimed to evaluate the influence of body mass index (BMI) on the cell proliferation markers (Bcl-2 and Ki67) on the endometrial polyps in postmenopause women. Methods: Prospective cross-sectional study using immunohistochemical analysis of the expression of the cell proliferation marker (Ki67) and an anti-apoptotic gene (Bcl-2) in endometrial polyps, in postmenopausal women. The polyps were identified by hysteroscopy and all were removed. The patients were divided into two groups related to BMI: a) BMI <29.9 kg/m2 (normal weight); b) BMI >30 kg/m2 (obese). We analysed the expression of these markers in relation to polyp size, histological type and time since menopause. The interpretation of the Ki67 and Bcl-2 expression data in the endometrial polyps accounted for the percentage of positive cells: score 1 (mild: less than 5% of cells showed expression); score 2 (moderate: between 5 and 50% of cells showed expression); score 3 (severe: more than 50% of cells showed expression). Statistical analysis was performed using the SPSS Statistics program for Windows v23, and the non-parametric Mann-Whitney test was used to analyse the Bcl-2 and Ki67 expression in the glandular and stromal components of the polyps. A significance level of p<0.05 was adopted for rejecting the null hypothesis. Results: There was greater glandular expression of Ki67 in hyperplastic polyps (p=0.04) and greater expression of Bcl-2 in the stroma of polyps larger than 2 cm (p=0.04). No difference in the Ki67 and Bcl-2 expression was found in the glands and stroma of the polyps when compared obese and non-obese postmenopause patients. Conclusion: Our findings suggest that the BMI may not have influence on the proliferation markers (Ki67 and Bcl-2) in the polyps of postmenopausal women.