Obesity and menstrual disorders.

Obesity is a growing public health concern and is associated with a range of menstrual disorders, including heavy menstrual bleeding, oligomenorrhea, dysmenorrhea, and endometrial pathology. Investigations may be more logistically challenging in those in the population with obesity, and because of the heightened risk of endometrial malignancy, there should be a low threshold for biopsy to exclude endometrial hyperplasia. Although treatment modalities for women with obesity are broadly similar to those with a normal BMI, additional consideration must be given to the risks associated with estrogen in obesity. Outpatient management of heavy menstrual bleeding is a developing field and outpatient treatment modalities are preferable in the population with obesity to avoid the morbidity associated with anesthetics.

Tumor Suppression in Asymptomatic Postmenopausal Endometrial Polyps.

BACKGROUND/AIM: To investigate tumor suppression as an indicator of malignization potential within endometrial polyps in asymptomatic postmenopausal women. MATERIALS AND METHODS: Immunohistochemical studies of the phosphatase and tensin homolog (PTEN) were performed. Cases included 52 benign postmenopausal polyps, 19 endometrioid carcinomas with coexisting benign polyps, and 12 polyps with foci of carcinoma. Controls included 31 atrophic endometria and 32 benign premenopausal polyps. PTEN was scored by quantitative methods according to staining intensity. RESULTS: The mean epithelial and stromal PTEN H-score in postmenopausal benign endometrial polyps (193.8 and 123.2, respectively) was significantly higher than that in the atrophic endometrium (135.5 and 90.2, p=0.008), and premenopausal benign endometrial polyps (100.7 and 198.7, p<0.001). Significant difference between postmenopausal endometrial polyps and endometrial carcinoma was noticed in the epithelial compartment (193.8 vs. 65.7, respectively, p<0.001). CONCLUSION: Asymptomatic benign postmenopausal polyps have a distinctively high tumor suppression compared with endometrial cancer, suggesting low malignization potential.

Proliferation in Postmenopausal Endometrial Polyps-A Potential for Malignant Transformation.

Background and objectives: Endometrial polyps in asymptomatic postmenopausal women are often incidentally found, yet only 1.51% of them are malignant. Their potential for malignant transformation has not been adequately addressed. The aim of this study was to investigate the proliferation within endometrial polyps as one of the indicators of their malignization potential in asymptomatic postmenopausal women. Materials and Methods: Immunohistochemical studies of Ki-67 were performed. Cases included 52 benign postmenopausal polyps, 19 endometrioid carcinoma with coexisting benign polyps, 12 polyps with foci of carcinoma and 4 cases of polyps, which later developed carcinoma. The control group included 31 atrophic endometria and 32 benign premenopausal polyps. Ki-67 was scored in either 10 or 20 "hot spot" fields, as percentage of positively stained cells. Results: The median epithelial Ki-67 score in postmenopausal benign polyps (4.7%) was significantly higher than in atrophic endometria (2.41%, p < 0.0001) and significantly lower than in premenopausal benign polyps (11.4%, p = 0.003) and endometrial cancer (8.3%, p < 0.0001). Where endometrial polyps were found in association with endometrial carcinoma, Ki-67 was significantly higher in cancer (p < 0.0001). No significant difference was found between Ki-67 scores of cancer focus and of the polyps tissue itself, respectively 2.8% and 4.55%, p = 0.37. Ki-67 expression, where polyps were resected and women later developed cancer, was not significantly different (p = 0.199). Conclusion: Polyps from asymptomatic postmenopausal women showed significantly more proliferation in both epithelial and stromal components than inactive atrophic endometria but less than premenopausal benign polyps and/or endometrial cancer. Benign postmenopausal endometrial polyps exhibit low proliferative activity, suggesting low malignant potential and may not require resection in asymptomatic women.

The impact of obesity and bariatric surgery on circulating and tissue biomarkers of endometrial cancer risk.

Obesity is the strongest risk factor for endometrial cancer (EC). To inform targeted screening and prevention strategies, we assessed the impact of obesity and subsequent bariatric surgery-induced weight loss on endometrial morphology and molecular pathways implicated in endometrial carcinogenesis. Blood and endometrial tissue were obtained from women with class III-IV obesity (body mass index ≥40 and ≥50 kg/m2 , respectively) immediately prior to gastric bypass or sleeve gastrectomy, and at two and 12 months' follow up. The endometrium underwent pathological examination and immunohistochemistry was used to quantify proliferation (Ki-67), oncogenic signaling (PTEN, pAKT, pERK) and hormone receptor (ER, PR) expression status. Circulating biomarkers of insulin resistance, reproductive function and inflammation were also measured at each time point. Seventy-two women underwent bariatric surgery. At 12 months, the mean change in total and excess body weight was -32.7 and -62.8%, respectively. Baseline endometrial biopsies revealed neoplastic change in 10 women (14%): four had EC, six had atypical hyperplasia (AH). After bariatric surgery, most cases of AH resolved (5/6) without intervention (3/6) or with intrauterine progestin (2/6). Biomarkers of endometrial proliferation (Ki-67), oncogenic signaling (pAKT) and hormone receptor status (ER, PR) were significantly reduced, with restoration of glandular PTEN expression, at 2 and 12 months. There were reductions in circulating biomarkers of insulin resistance (HbA1c, HOMA-IR) and inflammation (hsCRP, IL-6), and increases in reproductive biomarkers (LH, FSH, SHBG). We found an unexpectedly high prevalence of occult neoplastic changes in the endometrium of women undergoing bariatric surgery. Their spontaneous reversal and accompanying down-regulation of PI3K-AKT-mTOR signaling with weight loss may have implications for screening, prevention and treatment of this disease.

Obesity and menstrual disorders.

Obese women often present with oligomenorrhoea, amenorrhoea or irregular periods. The association between obesity and heavy menstrual bleeding is not well documented and data on its prevalence are limited. While the investigation protocols should be the same as for women of normal weight, particular focus is required to rule out endometrial hyperplasia in obese women. The treatment modalities of menstrual disorders for obese women will be, in principle, similar to those of normal weight. However, therapeutic outcomes in terms of effectiveness and adverse outcomes need special consideration when dealing with women with a high body mass index (BMI). Here, different treatment strategies are reviewed paying particular attention to the effect of weight on their efficacy and the challenges of providing each treatment option. This chapter aims to review the current literature and address areas where further evidence is needed, which will subsequently influence clinical practice.

Peroxisome proliferator-activated receptors modulate proliferation and angiogenesis in human endometrial carcinoma.

Peroxisome proliferator-activated receptors (PPAR) and retinoid X receptors (RXR) are implicated in the development of several obesity-related cancers. Little is known of either the expression or function of PPARs and RXRs in endometrial cancer although this increasingly common disease is highly associated with both obesity and insulin resistance. We investigated the expression of PPAR and RXR subtypes in human endometrial cancers and normal endometrium with immunoblotting and immunohistochemistry and subsequently showed PPAR/RXR binding preferences by coimmunoprecipitation. To determine the functions of PPARs within the endometrium, we investigated proliferation, apoptosis, PTEN expression, and secretion of vascular endothelial growth factor (VEGF) in endometrial cell lines after reducing the expression of PPARα and PPARγ with antisense RNA. The functional effects of PPAR ligands were also investigated in vitro. We identified differential expression of PPAR and RXR subtypes in endometrial cancers and discovered that PPARγ expression correlated with expression of PTEN. PPARα activation influences endometrial cell growth and VEGF secretion. PPARγ activation reduces proliferation of endometrial cells via regulation of PTEN and appears to reduce VEGF secretion. We conclude that the PPAR/RXR pathway contribute to endometrial carcinogenesis by control of PTEN expression and modulation of VEGF secretion. We propose that PPAR ligands should be considered for clinical investigation in early phase studies of women with endometrial cancer.