The expression of the hormone receptors in the endometrium and endometrial polyps in postmenopausal women and its relationship to body mass index

Risk of Pre-Malignancy or Malignancy in Postmenopausal Endometrial Polyps: A CHAID Decision Tree Analysis

BACKGROUND AND AIMS

Postmenopausal endometrial polyps are commonly managed by surgical resection; however, expectant management may be considered for some women due to the presence of medical co-morbidities, failed hysteroscopies or patient's preference. This study aimed to identify patient characteristics and ultrasound morphological features of polyps that could aid in the prediction of underlying pre-malignancy or malignancy in postmenopausal polyps.

METHODS

Women with consecutive postmenopausal polyps diagnosed on ultrasound and removed surgically were recruited between October 2015 to October 2018 prospectively. Polyps were defined on ultrasound as focal lesions with a regular outline, surrounded by normal endometrium. On Doppler examination, there was either a single feeder vessel or no detectable vascularity. Polyps were classified histologically as benign (including hyperplasia without atypia), pre-malignant (atypical hyperplasia), or malignant. A Chi-squared automatic interaction detection (CHAID) decision tree analysis was performed with a range of demographic, clinical, and ultrasound variables as independent, and the presence of pre-malignancy or malignancy in polyps as dependent variables. A 10-fold cross-validation method was used to estimate the model's misclassification risk.

RESULTS

There were 240 women included, 181 of whom presented with postmenopausal bleeding. Their median age was 60 (range of 45-94); 18/240 (7.5%) women were diagnosed with pre-malignant or malignant polyps. In our decision tree model, the polyp mean diameter (≤13 mm or >13 mm) on ultrasound was the most important predictor of pre-malignancy or malignancy. If the tree was allowed to grow, the patient's body mass index (BMI) and cystic/solid appearance of the polyp classified women further into low-risk (≤5%), intermediate-risk (>5%-≤20%), or high-risk (>20%) groups.

CONCLUSIONS

Our decision tree model may serve as a guide to counsel women on the benefits and risks of surgery for postmenopausal endometrial polyps. It may also assist clinicians in prioritizing women for surgery according to their risk of malignancy.

Expression levels of BCL2 and MKI67 in endometrial polyps in postmenopausal women and their correlation with obesity

Obesity is associated with numerous diseases, including endometrial disorders in postmenopausal women, such as adenocarcinoma, hyperplasias and endometrial polyps, and the risk of malignant transformation of these structures. The present study evaluated the influence of body mass index (BMI) on cell proliferation (BCL2 and MKI67) in endometrial polyps in postmenopausal women. A prospective cross-sectional study using immunohistochemical analysis of the expression of a cell proliferation marker (MKI67) and an anti-apoptotic gene (BCL2) in endometrial polyps in postmenopausal women was performed. The patients were divided into three groups depending on BMI: i) <24.9 kg/m² (normal); ii) >25 and <29.9 kg/m² (overweight); and iii) >30 kg/m² (obese). The present study analyzed the expression of these markers in relation to polyp size, histological type and time since menopause in 38 patients. The interpretation of MKI67 and BCL2 expression accounted for the percentage of positive cells (scores): 1 (weak), <5% of cells showed expression; 2 (moderate), between 5 and 50%; and 3 (intense), >50%. Statistical analysis was performed using GraphPad InStat version 3.00 software. ANOVA was used to analyze BCL2 and MKI67 expression. A significance level of P<0.05 was adopted for rejecting the null hypothesis. There was greater glandular expression of MKI67 in obese women than in normal weight women (P=0.02) and greater expression of BCL2 in the stroma of polyps >2 cm (P=0.03). Hyperplastic polyps exhibited hyperexpression of MKI67 (P=0.04) compared with atrophic polyps. No difference in MKI67 and BCL2 expression was identified in the glands and stroma of polyps when comparing overweight and obese postmenopausal patients. The present findings suggest that BMI has an influence on proliferation markers (MKI67) in the polyps of postmenopausal women and that polyps >2 cm exhibit hyperexpression of BCL2 in the stroma.

Immunohistochemical assessment of symptomatic postmenopausal endometrial polyps in tamoxifen users and nonusers: a case control study

BACKGROUND

Endometrial polyps are common in postmenopausal women, and the effect of tamoxifen use (a risk factor for endometrial polyps) on their pathogenesis is unclear.

OBJECTIVES

To evaluate the expression of hormone receptors and markers for proliferation/apoptosis (Ki-67 and Bcl-2) in endometrial polyps in postmenopausal users and nonusers of tamoxifen.

DESIGN AND SETTING

Cross-sectional analytical study in a tertiary-level academic hospital.

METHODS

46 women (14 tamoxifen users and 32 nonusers) with postmenopausal bleeding underwent hysteroscopic resection of endometrial polyps. Polyp samples were immunohistochemically assessed for detection of Ki-67, Bcl-2 and estrogen and progesterone receptors.

RESULTS

Analysis on the glandular component of the polyps revealed progesterone receptor expression in the polyps of 96.9% of the nonusers of tamoxifen, and 92.3% of the tamoxifen users (P = 0.499). All polyps in nonusers and 92.3% of those in users were also positive for estrogen receptors (P = 0.295). Ki-67 was expressed in 75% of the polyps in the tamoxifen users and 82.8% of those in the nonusers. All endometrial polyps expressed Bcl-2.

CONCLUSIONS

The immunohistochemical analysis on endometrial polyps demonstrated that, although tamoxifen is considered to be a risk factor for endometrial polyps, there were no significant differences in the expression of hormone receptors between users and nonusers of tamoxifen. There were no between-group differences in Ki-67 and Bcl-2 expression, and all patients displayed inhibition of apoptosis by Bcl-2, thus supporting the theory that polyps develop due to inhibition of apoptosis, and not through cell proliferation.

Differences in estrogen and progesterone receptor expression in endometrial polyps and atrophic endometrium of postmenopausal women with and without exposure to tamoxifen

Postmenopausal women who use tamoxifen present with an increased incidence of endometrial alterations, such as polyps and hyperplasia, in addition to a higher risk of malignant endometrial neoplasms. Among these endometrial changes, polyps are the most common, with a pathogenesis associated with hormonal influence. The objective of this study was to compare the expression of estrogen receptors (ERs) and progesterone receptors (PRs) in endometrial polyps from tamoxifen users with that in endometrial polyps and the atrophic endometrium of postmenopausal tamoxifen non-users. Among women undergoing surgical hysteroscopy, 84 tamoxifen users with benign endometrial polyps were selected. This group was compared to 84 samples of atrophic endometrium and to 252 benign polyps from postmenopausal women who were not treated with tamoxifen. The expression of ER/PR was assessed by immunohistochemical analysis, according to the percentage of stained cells, intensity of nuclear staining and final score. The polyps from tamoxifen users exhibited a higher expression of ER and PR in the glandular epithelium and stroma compared to the atrophic endometrium (P<0.0001). Compared to the polyps from women not treated with tamoxifen, tamoxifen users exhibited a higher PR expression in the epithelium (P=0.0014) and stroma (P=0.0056), with no difference in the expression of ER. In conclusion, endometrial polyps frequently exhibit an increase in ER expression, regardless of tamoxifen use. High levels of PR expression appear to be consistent with the estrogen agonist effects of tamoxifen.

HER-2/neu (c-erbB-2) oncoprotein in hyperplastic endometrial polyps detected in two cats

The presence of HER-2/neu (c-erbB-2) oncoprotein, oestrogen-α receptor (ER), and progesterone receptor (PR) in hyperplastic endometrial polyps (EPs) of two cats with cystic endometrial hyperplasia-pyometra (CEH-P) complex was investigated. Immunohistochemistry assay for ER, PR and c-erbB-2 oncoprotein in the glandular and stromal tissue of the EPs was performed. ER and c-erbB-2 immunoreactivity was observed in the glandular epithelium of the EPs whereas PR immunoreactivity was detected only in the stromal fibroblasts. The c-erbB-2 oncoprotein may play a role with the ER in the pathogenesis of the hyperplastic EPs, although the role of this oncoprotein in the pathogenesis of EPs has yet to be determined.

Endometrial polyps in pre- and postmenopausal women: Factors associated with malignancy

OBJECTIVE

To evaluate the prevalence of premalignant and malignant polyps and their association with menopausal status, hormone therapy and clinical characteristics in perimenopausal and postmenopausal women.

METHODS

A surgical database was used to select pre- and postmenopausal women >or=40 years of age, submitted to hysteroscopic resection of endometrial polyps. The medical records of 475 women were reviewed and clinical characteristics and histological diagnosis of resected polyps were assessed.

RESULTS

The majority of women had benign endometrial lesions, 78.53% of which were endometrial polyps and 13.47% polyps with simple or complex endometrial hyperplasia without atypia. Polyps with endometrial hyperplasia with atypia comprised 1.05% of cases, while 2.74% were carcinomatous polyps. Analysis using prevalence ratios showed that premalignant and malignant lesions were associated with age and postmenopausal bleeding. Women >60 years of age had a prevalence ratio 3.28 times greater (95%CI: 1.19-9.07) of premalignant or malignant polyps. When only postmenopausal women were evaluated for the effect of age, those over 60 years of age had a prevalence 5.31 times greater (95%CI: 1.22-23.09), while those with postmenopausal bleeding had an age-adjusted prevalence ratio of 3.71 (95%CI: 1.21-11.34) compared to asymptomatic women. No significant association was found between arterial hypertension, diabetes mellitus, obesity, use of hormone therapy or tamoxifen and premalignancy or malignancy.

CONCLUSIONS

There was a low prevalence of premalignant and malignant lesions in endometrial polyps. Older women and those with postmenopausal bleeding had a greater prevalence of malignancy and in these cases hysteroscopic resection of endometrial polyps is mandatory.