[The long-term efficacy of metformin in megestrol acetate-based fertility-sparing treatment for patients with endometrial atypical hyperplasia and endometrioid endometrial cancer].

Objective: To assess the long-term efficacy of metformin in megestrol acetate (MA)-based fertility-sparing treatment for patients with endometrial atypical hyperplasia (EAH) and endometrioid endometrial cancer (EEC). Methods: The randomized controlled trail study was conducted from October 2013 to October 2017 in the Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China. Patients with EAH or EEC were firstly stratified according to pathology, and randomized to receive MA (160 mg orally, daily) plus metformin (500 mg orally, three times a day) or MA (160 mg orally, daily). Baseline data between two groups of patients were compared. Estimates of time to complete remission (CR) and recurrence-free survival (RFS) were calculated using the Kaplan-Meier method. Cox proportional-hazards regression model was used to estimate hazard ratios (HR) of related factors for recurrence-free survival. Quantitative data were represented by M (Q1, Q3). Results: A total of 150 patients were included, and 76 patients were allocated to receive MA plus metformin with the age of 32.5 (28.0, 36.0), while 74 patients received MA alone with the age of 32.0 (28.0, 36.0). By the end of follow-up period, 96.7% (n=145) of patients achieved complete remission, with a median follow-up time of 57.7 (26.7, 70.5) months. The median CR time for the MA plus metformin group and the MA alone group were 6.3 (3.5, 8.3) months and 6.8 (4.0, 9.3) months, respectively (P=0.193), with 2-year cumulative CR rate of 98.6% and 98.5%, respectively (P=0.879). The median time of RFS was 28.1 (12.5, 57.3) months for the MA plus metformin group and 33.3 (14.1, 62.5) months for the MA alone group (P=0.213), with a cumulative RFS rate of 61.9% and 65.8%, respectively (P=0.560). In the subgroup of non-obese (body mass index<28 kg/m2) patients with EAH, the median RFS times were 25.7 (7.6, 60.3) months and 47.3 (17.5, 64.8) months for the MA plus metformin group and the MA alone group, respectively (P=0.033), with a cumulative RFS rate of 57.5% and 80.6%, respectively (P=0.029). According to Cox proportional hazards regression analysis, undergoing assisted reproductive treatment (HR=2.358, 95%CI: 1.069-5.204, P=0.034) was identified as an independent risk factor for recurrence-free survival after complete remission of endometrial lesions. Conclusion: The long-term follow-up outcome indicates that there is no significant difference in CR time and RFS time between MA plus metformin therapy and MA alone therapy for patients with EAH or EEC.

Progestogens for endometrial protection in combined menopausal hormone therapy: A systematic review.

Menopausal women with an intact uterus choosing estrogens for menopausal symptom relief require a progestogen for endometrial protection. The aim of this systematic review was to evaluate the risks of endometrial hyperplasia resp. malignancy with different progestogens used in combined MHT. Overall, 84 RCTs were included. We found that 1) most studies were done with NETA, followed by MPA, MP and DYD and LNG, 2) most progestogens were only available as oral formulations, 3) the most frequently studied progestogens (oral MP, DYD, MPA, oral and transdermal NETA, transdermal LNG) were assessed in continuously as well as in sequentially combined MHT regimens, 4) FDA endometrial safety criteria were only fulfilled for some progestogen formulations, 5) most studies demonstrated endometrial protection for the progestogen dose and time period examined. However, 6) study quality varied which should be taken into account, when choosing a combined MHT, especially if off-label-use is chosen.

Comparative safety of conjugated estrogens/bazedoxifene versus estrogen/progestin combination hormone therapy among women in the United States: a multidatabase cohort study.

OBJECTIVE: To assess the risk of select safety outcomes including endometrial cancer, endometrial hyperplasia, and breast cancer among women using conjugated estrogens/bazedoxifene (CE/BZA) as compared with estrogen/progestin combination hormone therapy (EP). METHODS: We conducted a new-user cohort study in five US healthcare claims databases representing more than 92 million women. We included CE/BZA or EP new users from May 1, 2014, to August 30, 2019. EP users were propensity score (PS) matched to users of CE/BZA. Incidence of endometrial cancer, endometrial hyperplasia, breast cancer, and eight additional cancer and cardiovascular outcomes were ascertained using claims-based algorithms. Rate ratios (RR) and differences pooled across databases were estimated using random-effects models. RESULTS: The study population included 10,596 CE/BZA and 33,818 PS-matched EP new users. Rates of endometrial cancer and endometrial hyperplasia were slightly higher among CE/BZA users (1.6 and 0.4 additional cases per 10,000 person-years), although precision was limited because of small numbers of cases (endometrial cancer: RR, 1.50 [95% confidence interval {CI}, 0.79-2.88]; endometrial hyperplasia: RR, 1.69 [95% CI, 0.51-5.61]). Breast cancer incidence was lower in CE/BZA users (9.1 fewer cases per 10,000 person-years; RR, 0.79; 95% CI, 0.58-1.05). Rates of other outcomes were slightly higher among CE/BZA users, but with confidence intervals compatible with a wider range of possible associations. CONCLUSIONS: CE/BZA users might experience slightly higher rates of endometrial cancer and endometrial hyperplasia, and a lower rate of breast cancer, than EP users in the first years of use.

Chloroform Fraction of Drymaria cordata Linn (CFDC) Suppresses Estradiol Benzoate- Induced Endometrial Hyperplasia.

BACKGROUND: The diagnosis of uterine dysfunction (endometrial hyperplasia) is on the rise. The available treatment is quite expensive and associated with some side effects. The therapeutic potential of natural products is now being explored, as they are easily available with little or no side effects. Drymaraia cordata is folklorically utilized in the treatment of diverse ailments including uterine fibroids. OBJECTIVES: This study aims to investigate the potential therapeutic effect of chloroform fraction of methanol extract of Drymaria cordata (CFDC) in estradiol benzoate (EB)-induced endometrial hyperplasia. METHODS: Thirty-six rats were randomly divided equally into six groups. These included control group, CFDC: (100 mg/kg), CFDC: (200 mg/kg), EB: (2 mg/kg), EB + CFDC (100 mg/kg), and EB + CFDC (200 mg/kg). Endometrial hyperplasia (EH) was induced by intraperitoneal injection of EB. The levels of estrogen (E2), progesterone (PG), Follicle stimulating hormone (FSH), Luteinizing hormone (LH), Malondialdehyde (MDA), Superoxide dismutase (SOD), and Glutathione peroxidase (GSH-Px) activities were determined using ELISA technique. The uterine histological assessment and immunohistochemical expression levels of estrogen receptor, Ki-67, cytochrome c, and caspase 3 were carried out. RESULTS: EH was severely expressed in the uterine section of EB-treated rats. However, CFDC administration improved the pathological features of the animal model. The sex hormones levels were increased in the EB-treated group, which were significantly reduced by CFDC. The antioxidant indices were also restored by CFDC. Immunoexpression levels of ERα and Ki-67 were downregulated while cytochrome c and caspase 3 were upregulated by CFDC. CONCLUSION: This study suggests that CFDC contains phytochemicals that can protect against EB-induced EH via modulation of hormonal signaling, apoptotic machinery, and oxidative indices.

Paeonol ameliorates endometrial hyperplasia in mice via inhibiting PI3K/AKT pathway-related ferroptosis.

BACKGROUND: Paeonol (Pae) is one of the active ingredients from components of Guizhi Fuling Capsule, a traditional Chinese medicine widely used for the treatment of women's diseases, which exhibits various biological and pharmacological activities. PURPOSE: The objective of this study was to investigate the molecular mechanism underlying the role of Pae in protecting against endometrial hyperplasia (EH). METHODS: CCK-8 assay was performed to detect the effect of Pae on cell proliferation. Hematoxylin and eosin (H&E) staining was performed to evaluate uterine tissue structure. A network pharmacology study was performed to search the disease targets. Single-cell transcriptome analysis was performed with uterine tissues from 3 healthy donors and 3 EH patients on 10X Genomics platform. Changes in lipid peroxidation were detected by the MDA reaction. IHC assay, Western blot, immunofluorescence and RT-qPCR were used to study the effects of estradiol and Pae on the expression levels of GPX4, PI3K, AKT, p-PI3K, p-AKT in mice. RESULTS: Pae treatment resulted in a decrease in cell viability of endometrial epithelial cells. Loss of uterus weight and morphology changes were observed in mice. In addition, Fe iron concentration and MDA levels increased, while the expression of GPX4, p-PI3K and p-AKT diminished. CONCLUSIONS: Pae exhibited obvious alleviative activity in estradiol-induced mice via PI3K/AKT signaling pathway-regulated ferroptosis.

Effects of Isoflavone Supplementation on the Response to Medroxyprogesterone in Premenopausal Women with Nonatypical Endometrial Hyperplasia: A Randomized, Double-Blind, Placebo-Controlled Trial.

Objective: The purpose of this study was to evaluate the impact of isoflavone supplementation compared with placebo on endometrial histology and serum estradiol levels in premenopausal women with nonatypical endometrial hyperplasia. Materials and Methods: The present double-blindplacebo-controlled clinical trial was conducted on 100 women with nonatypical endometrial hyperplasia in the age range of 30 to 45 years. Participants were randomly assigned to receive 50 mg of isoflavone (n = 50) or placebos (n = 50) daily for three months. Both groups received the standard treatment of nonatypical endometrial hyperplasia. Endometrial biopsy and blood samples were taken at the baseline and three months after the intervention. The incidence of drug side effects was assessed as well. Results: After three months, 88.4% of isoflavone-administered subjects had a significant histological improvement compared to 68.9% subjects in the placebo group (P=0.02). There were no significant differences between the two groups in the changes of serum estradiol levels and the incidence of drug side effects. Conclusion: The findings of the present study demonstrated that the coadministration of 50 mg of isoflavones and medroxyprogesterone acetate increases the treatment efficacy in women with nonatypical endometrial hyperplasia. Clinical Trial Registration. This trial was registered on the Iranian website for clinical trial registration (https://www.irct.ir/trial/53553).

Rare case of coexisting ovarian Brenner tumour and ovarian stromal hyperplasia presenting with persistent endometrial hyperplasia following treatment with levonorgestrel-intrauterine system.

Endometrial hyperplasia (EH) is a precursor of endometrial cancer. It arises in an environment of unopposed oestrogen. Treatment is based on a combination of weight management, diet and exercise, and the use of progestogens either via a levonogestrel-intrauterine system (LNG-IUS) or orally. The LNG-IUS is the first-line recommendation for EH without atypia. Recurrences are rare, and any recurrences despite prolonged treatment and control of risk factors necessitate a thorough consideration of other oestrogenic sources. This case report presents a rare case of a coexisting ovarian Brenner tumour and ovarian stromal hyperplasia in a menopausal patient in her 50s with recurrent EH despite earlier regression. The above histology may have provided the additional oestrogenic influence. This patient subsequently underwent a definitive hysterectomy and bilateral salpingo-oophorectomy (BSO). It is important to maintain a high index of suspicion for potential oestrogenic influences in cases of refractory EH that are not identifiable on imaging. BSO should be considered at the time of hysterectomy in such cases of unidentified oestrogenic foci.

Risk of Endometrial Polyps, Hyperplasia, Carcinoma, and Uterine Cancer After Tamoxifen Treatment in Premenopausal Women With Breast Cancer.

Importance: The association of tamoxifen use with the risk of uterine diseases, such as endometrial cancer, in premenopausal women with breast cancer remains controversial. However, many studies have reported an increased risk of uterine disease among postmenopausal tamoxifen users. Objective: To investigate the association of tamoxifen use with the risk of endometrial cancer and other uterine diseases in premenopausal women with breast cancer. Design, Setting, and Participants: A nationwide, population-based, retrospective longitudinal cohort study with an 18-year study period was conducted using data obtained from the Korean National Health Insurance Service. Participants included premenopausal women aged 20 to 50 years with breast cancer diagnoses between January 2003 and December 2018. Data were analyzed from April to December 2021. Exposures: Tamoxifen treatment. Main Outcomes and Measures: The incidence of uterine diseases, including endometrial cancer, hyperplasia, polyps, and other uterine cancers, was identified in the study cohort using insurance claim codes. The incidence of uterine diseases per 1000 person-years was compared between women receiving tamoxifen and those not treated with adjuvant hormone therapy. Multivariable Cox proportional hazard regression analysis was performed to determine the risk of each uterine disease. Results: Among 78 320 female participants with a mean (SD) age of 42.1 (6.1) years, 34 637 (44.2%) were categorized into the tamoxifen group and 43 683 (55.8%) were categorized into the control group. Among tamoxifen users, during the mean (SD) follow-up duration of 6.13 (4.15) years, the incidence of newly diagnosed endometrial polyps was 20.13 cases per 1000 person-years, that of endometrial hyperplasia was 13.49 cases per 1000 person-years, that of endometrial cancer was 2.01 cases per 1000 person-years, and that of other uterine cancers was 0.45 cases per 1000 person-years. The risk of endometrial cancer was higher in the tamoxifen group than in the control group (hazard ratio, 3.77; 95% CI, 3.04-4.66) after adjusting for age, body mass index, history of diabetes, hypertension, dyslipidemia, polycystic ovary syndrome, gonadotropin-releasing hormone agonist treatment, and trastuzumab treatment. Conclusions and Relevance: In this longitudinal cohort study, premenopausal Korean women with breast cancer who received tamoxifen as adjuvant hormone therapy had a significantly increased risk of endometrial hyperplasia, polyps, carcinoma, and other uterine cancers compared with those who were not treated with adjuvant hormone therapy. These findings suggest that clinicians should consider the risk of uterine disease among tamoxifen users, including premenopausal women.

Piceatannol SNEDDS Attenuates Estradiol-Induced Endometrial Hyperplasia in Rats by Modulation of NF-κB and Nrf2/HO-1 Axes.

Endometrial hyperplasia (EH) is the most common risk factor for endometrial malignancy in females. The pathogenesis of EH has been directly linked to uterine inflammation, which can result in abnormal cell division and decreased apoptosis. Piceatannol (PIC), a natural polyphenolic stilbene, is known to exert anti-inflammatory, antioxidant and anti-proliferative activities. The aim of the present study was to examine the potential preventive role of PIC in estradiol benzoate (EB)-induced EH in rats. A self-nanoemulsifying drug delivery system (SNEDDS) was prepared to improve the solubility of the PIC. Therefore, thirty female Wistar rats were divided into five groups: (1) control, (2) PIC SNEDDS (10 mg/kg), (3) EB (0.6 mg/kg), (4) EB + PIC SNEDDS (5 mg/kg) and (5) EB + PIC SNEDDS (10 mg/kg). The administration of PIC SNEDDS prevented EB-induced increases in uterine weights and histopathological changes. Additionally, it displayed pro-apoptotic and antioxidant activity in the endometrium. Immunohistochemical staining of uterine sections co-treated with PIC SNEDDS showed significantly decreased expression of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and nuclear transcription factor-kappa B (NF-κB). This anti-inflammatory effect was further confirmed by a significant increase in Nrf2 and heme oxygenase-1 (HO-1) expression. These results indicate that SNEDDS nanoformulation of PIC possesses protective effects against experimentally induced EH.

Chrysin attenuates estradiol-induced endometrial hyperplasia in rats via enhancing PPARα activity.

Endometrial hyperplasia (EH) is a complex condition that commonly affects women after menopause. Since the current available treatments for EH are mainly invasive, there is a need for developing new treatment modalities. Chrysin (Ch) is a dihydroxyflavone with numerous promising therapeutic potentials. In this study, Ch's protective effects on estradiol (E2)-induced EH were studied in rats. Animals were allocated randomly to five groups and were treated for 4 weeks as follows: Group 1, control: received the vehicle; group 2, Ch: received Ch 25 mg/kg; group 3, estradiol (E2): received E2 (3 mg/kg) 3 × weekly subcutaneously and the vehicle. Group 4, E2 + Ch 10 mg/kg and group 5, E2 + Ch 25 mg/kg: Ch was given once daily at 10 mg/kg or 25 mg/kg, respectively. In addition, E2 was administered 3 × weekly (3 mg/kg) in groups 4 and 5. Ch inhibited the E2-induced increase in uterine weights and histopathological changes. Ch lowered the cyclin D1 expression. Ch raised the caspase-3 content and Bax mRNA expression. Furthermore, it corrected the raised Bcl2 mRNA expression due to E2. Ch inhibited MDA accumulation and GSH depletion. It also prevents E2-induced SOD and GPx exhaustion. It also ameliorated the rise in NFκB, TNF-α, and IL-6 expression. These effects were correlated with an enhanced PPARα activity ratio relative to the E2 group. This suggests that Ch attenuates EH in this model by exerting anti-proliferative, anti-oxidant, and anti-inflammatory effects partially through increasing PPARα activity.

Use of oral estradiol plus vaginal progesterone in healthy postmenopausal women.

OBJECTIVES: To compare the effect of oral estradiol (E2) plus vaginal progesterone (P4) against placebo on endometrial thickness, endometrial biopsy pathology, cervical cytology and total cancer incidence among healthy postmenopausal women. STUDY DESIGN: This study is a sub-analysis of the Early versus Late Intervention Trial with Estradiol (ELITE), a randomized, double-blinded, placebo-controlled trial that previously demonstrated that hormone therapy (HT) was associated with less progression of subclinical atherosclerosis than placebo when therapy was initiated within 6 years after menopause but not when it was initiated 10 or more years after menopause. This sub-analysis included only ELITE participants with an intact uterus, who were randomized to either daily oral micronized 17-beta-E2 1 mg/day with 4% vaginal micronized P4 gel 45 mg/day for 10 days each month or placebo. MAIN OUTCOME MEASURES: Participants were evaluated at baseline and annually during a median follow-up of 4.8 years for endometrial thickness as determined by pelvic transvaginal ultrasound followed by an endometrial biopsy when indicated, and cervical cytology and cancer incidence. RESULTS: Over up to 80 months of follow-up, participants randomized to oral E2 plus vaginal P4 had progressive and statistically significant increases in endometrial thickness (p<0.001), underwent more endometrial biopsies and had a higher rate of endometrial hyperplasia on endometrial biopsy compared with the placebo group. Due to the close follow-up of participants in the trial protocol, these abnormal findings were effectively treated. CONCLUSION: Our results suggest that 10 days of vaginal P4 45 mg/day is insufficient to completely oppose the effect of oral E2 1 mg/day on the endometrium. Further studies are needed to test alternative doses or frequencies of administration of vaginal P4 for adequate endometrial protection from E2 therapy among postmenopausal women. ClinicalTrials.gov registration NCT00114517.

Guizhi Fuling Capsule ameliorates endometrial hyperplasia through promoting p62-Keap1-NRF2-mediated ferroptosis.

ETHNOPHARMACOLOGICAL RELEVANCE: Guizhi Fuling Capsule (GFC) is a classical traditional Chinese medicine officially recorded in Synopsis of the Golden Chamber and has long been used to treat gynecological diseases in China. However, scientific evidence for the anti-endometrial hyperplasia potential of GFC used in traditional medicine is lacking. AIM OF THE STUDY: This study evaluated whether GFC protects against endometrial hyperplasia and its potential mechanism in mice. METHODS AND MATERIALS: We used estrogen (estradiol) to induce endometrial hyperplasia in mice. C57BL/6 mice were treated with estradiol subcutaneously for 21 days, and GFC (75 mg/kg and 150 mg/kg) was given intragastric administration from the first day of the modeling. H&E staining is used to evaluate endometrial tissue structure change. Malondialdehyde was measured to explore lipid peroxidation. Western blot, immunohistochemistry and immunofluorescence were performed to observe the expressions of GPX4, p62, Keap1 and NRF2. RESULTS: The degree of ferroptosis in endometrial tissue of patients with endometrial hyperplasia was lower than normal endometrial tissue. In addition, ferroptosis inducer imidazole ketone erastin could improve endometrial hyperplasia in mice. Interestingly, GFC significantly alleviated endometrial hyperplasia through triggering ferroptosis. Furthermore, GFC inhibited p62-Keap1-NRF2 pathway in estradiol-induced endometrial hyperplasia model. CONCLUSIONS: GFC may attenuate estrogen-induced endometrial hyperplasia in mice through triggering ferroptosis via inhibiting p62-Keap1-NRF2 pathway. These findings suggest that GFC might act as a promising traditional Chinese medicine to treat endometrial hyperplasia.

Methyl palmitate reversed estradiol benzoate-induced endometrial hyperplasia in female rats.

Early detection and treatment of endometrial hyperplasia (EH) is mandatory for endometrial cancer prevention. Several bioactive agents of plant origin have been shown to elicit their chemotherapeutic effect against tumors and cancer via induction of mitochondrial permeability transition(mPT) pore opening. This research was therefore aimed at evaluating the potential chemopreventive effect of methyl palmitate (MP), on estradiol benzoate(EB)-induced EH, looking at the mitochondrial-mediated pathway and other possible mechanisms of action. Mitochondria were isolated using differential centrifugation. The mPT pore, mitochondrial ATPase (mATPase) activity, lipid peroxidation and cytochrome c release were determined by standard methods using spectrophotometer. Uterine interleukin 1b, MDA levels and SOD, GSH activities, were determined using commercially available kits. The uterine histological and immunohistochemical assessment of estrogen receptor (ERα), IL-1b and caspas-3 were carried out. The fibroblast cell count density was determined using histomorphometry. At all the concentrations of MP used, there was no significant induction of mPT pore opening, neither any enhancement of mATPase activity nor release of cytochrome c when compared to the control. Similar pattern of results were recorded for the in vivo study. However, there was marked increase in the uterine MDA and interleukin 1b levels, with concurrent decrease in SOD and GSH activities, in the EB-treated group, which was significantly reversed by MP co-administration. Endometrial Hyperplasia observed in the EB-treated group was ameliorated by MP co-administration. The immunoexpression of ERα and IL-1b in the EB-treated group was reversed by MP co-administration. This study suggests anti-inflammatory, antioxidant and anti-proliferative potential of MP against EB-induced EH.

Levonorgestrel intrauterine system for endometrial protection in women with breast cancer on adjuvant tamoxifen.

BACKGROUND: Adjuvant tamoxifen reduces the risk of breast cancer recurrence in women with oestrogen receptor-positive breast cancer. Tamoxifen also increases the risk of postmenopausal bleeding, endometrial polyps, hyperplasia, and endometrial cancer. The levonorgestrel-releasing intrauterine system (LNG-IUS) causes profound endometrial suppression. This systematic review considered the evidence that the LNG-IUS prevents the development of endometrial pathology in women taking tamoxifen as adjuvant endocrine therapy for breast cancer. OBJECTIVES: To determine the effectiveness and safety of the levonorgestrel intrauterine system (LNG-IUS) in pre- and postmenopausal women taking adjuvant tamoxifen following breast cancer for the outcomes of endometrial and uterine pathology including abnormal vaginal bleeding or spotting, and secondary breast cancer events. SEARCH METHODS: We searched the following databases on 29 June 2020; The Cochrane Gynaecology and Fertility Group specialised register, Cochrane Central Register of Controlled Trials, MEDLINE, Embase, PsycINFO and Cumulative Index to Nursing and Allied Health Literature. We searched the Cochrane Breast Cancer Group specialised register on 4 March 2020. We also searched two trials registers, checked references for relevant trials and contacted study authors and experts in the field to identify additional studies. SELECTION CRITERIA: We included randomised controlled trials (RCTs) of women with breast cancer on adjuvant tamoxifen that compared the effectiveness of the LNG-IUS with endometrial surveillance versus endometrial surveillance alone on the incidence of endometrial pathology. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures recommended by Cochrane. The primary outcome measure was endometrial pathology (including polyps, endometrial hyperplasia, or endometrial cancer), diagnosed at hysteroscopy or endometrial biopsy. Secondary outcome measures included fibroids, abnormal vaginal bleeding or spotting, breast cancer recurrence, and breast cancer-related deaths. We rated the overall certainty of evidence using GRADE methods. MAIN RESULTS: We included four RCTs (543 women analysed) in this review. We judged the certainty of the evidence to be moderate for all of the outcomes, due to imprecision (i.e. limited sample sizes and low event rates). In the included studies, the active treatment arm was the 20 µg/day LNG-IUS plus endometrial surveillance; the control arm was endometrial surveillance alone. In tamoxifen users, the LNG-IUS probably reduces the incidence of endometrial polyps compared to the control group over both a 12-month period (Peto odds ratio (OR) 0.22, 95% confidence interval (CI) 0.08 to 0.64, I² = 0%; 2 RCTs, n = 212; moderate-certainty evidence) and over a long-term follow-up period (24 to 60 months) (Peto OR 0.22, 95% CI 0.13 to 0.39; I² = 0%; 4 RCTs, n = 417; moderate-certainty evidence). For long-term follow-up, this suggests that if the incidence of endometrial polyps following endometrial surveillance alone is assumed to be 23.5%, the incidence following LNG-IUS with endometrial surveillance would be between 3.8% and 10.7%.  The LNG-IUS probably slightly reduces the incidence of endometrial hyperplasia compared with controls over a long-term follow-up period (24 to 60 months) (Peto OR 0.13, 95% CI 0.03 to 0.67; I² = 0%; 4 RCTs, n = 417; moderate-certainty evidence). This suggests that if the chance of endometrial hyperplasia following endometrial surveillance alone is assumed to be 2.8%, the chance following LNG-IUS with endometrial surveillance would be between 0.1% and 1.9%. However, it should be noted that there were only six cases of endometrial hyperplasia. There was insufficient evidence to reach a conclusion regarding the incidence of endometrial cancer in tamoxifen users, as no studies reported cases of endometrial cancer. At 12 months of follow-up, the LNG-IUS probably increases abnormal vaginal bleeding or spotting compared to the control group (Peto OR 7.26, 95% CI 3.37 to 15.66; I² = 0%; 3 RCTs, n = 376; moderate-certainty evidence). This suggests that if the chance of abnormal vaginal bleeding or spotting following endometrial surveillance alone is assumed to be 1.7%, the chance following LNG-IUS with endometrial surveillance would be between 5.6% and 21.5%. By 24 months of follow-up, abnormal vaginal bleeding or spotting occurs less frequently than at 12 months of follow-up, but is still more common in the LNG-IUS group than the control group (Peto OR 2.72, 95% CI 1.04 to 7.10; I² = 0%; 2 RCTs, n = 233; moderate-certainty evidence). This suggests that if the chance of abnormal vaginal bleeding or spotting following endometrial surveillance alone is assumed to be 4.2%, the chance following LNG-IUS with endometrial surveillance would be between 4.4% and 23.9%. By 60 months of follow-up, there were no cases of abnormal vaginal bleeding or spotting in either group. The numbers of events for the following outcomes were low: fibroids (n = 13), breast cancer recurrence (n = 18), and breast cancer-related deaths (n = 16). As a result, there is probably little or no difference in these outcomes between the LNG-IUS treatment group and the control group.  AUTHORS' CONCLUSIONS: The LNG-IUS probably slightly reduces the incidence of benign endometrial polyps and endometrial hyperplasia in women with breast cancer taking tamoxifen. At 12 and 24 months of follow-up, the LNG-IUS probably increases abnormal vaginal bleeding or spotting among women in the treatment group compared to those in the control. Data were lacking on whether the LNG-IUS prevents endometrial cancer in these women. There is no clear evidence from the available RCTs that the LNG-IUS affects the risk of breast cancer recurrence or breast cancer-related deaths. Larger studies are necessary to assess the effects of the LNG-IUS on the incidence of endometrial cancer, and to determine whether the LNG-IUS might have an impact on the risk of secondary breast cancer events.

Progesterone and endometrial cancer.

It is well established that unopposed estrogen, either endogenous or therapeutic, can induce endometrial hyperplasia and potentially endometrial cancer (EC). Anovulatory cycles, obesity, and insulin resistance are major risk factors for EC. Progestogen (progesterone and progestin), including levonorgestrel intrauterine device, are able to prevent or to treat hyperplasia, atypical hyperplasia, and even well-differentiated EC, as presented in this review. During menopausal hormone therapy, progestogens protect the endometrium against the proliferative effects of estrogens in women with a uterus. Whereas, recent epidemiologic data suggest that micronized progesterone (MP) is apparently safer for the breast, it could be less efficient than synthetic progestin on the endometrium. However, several studies from biopsies during treatment with MP do not show any increased risk of hyperplasia. Lack of compliance could explain the results on EC.

Assessment of Tamoxifen-Related Endometrial Changes in Premenopausal Female Patients With Diffusion-Weighted Magnetic Resonance Imaging.

PURPOSE: To evaluate tamoxifen-related endometrial changes in premenopausal female patients with diffusion-weighted magnetic resonance imaging (DWI). METHODS: This prospective study was performed on 71 premenopausal female patients (mean age, 41 years) who were receiving tamoxifen therapy. All patients underwent magnetic resonance imaging with DWI of the pelvis and hysteroscopic-guided endometrial biopsy. The apparent diffusion coefficient (ADC) values of the endometrial plate were calculated and correlated with pathological results. RESULTS: The mean ADCs of tamoxifen-related benign endometrial lesions (1.35 ± 0.19 and 1.32 ± 0.13 × 10 mm/s) were significantly higher (P = 0.001) than those of normal endometrial plate (0.95 ± 0.11 and 0.93 ± 0.11 × 10 mm/s) by both reviewers, respectively. The cutoff ADC values used to differentiate tamoxifen-related benign endometrial lesions from normal endometrium were 1.07 and 1.02 × 10 mm/s with areas under the curve of 0.94 and 0.93 and accuracy of 94.4 and 95.8 by both reviewers, respectively. The mean ADC values of endometrial polyp (EP) (1.44 ± 0.19 and 1.42 ± 0.22 × 10 mm/s) were significantly higher (P = 0.001) than those of endometrial hyperplasia (EH) (1.25 ± 0.19 and 1.23 ± 0.19 × 10 mm/s) by both reviewers, respectively. The cutoff ADC values used to differentiate EP from EH were 1.38 × 10 and 1.36 × 10 mm/s with areas under the curve of 0.81 and 0.77 and accuracy of 80% and 70% by both reviewers, respectively. There was an insignificant difference in ADC value between typical and atypical EH. The ADC values of endometrial cancer (0.80 and 0.78 × 10 mm/s) were lower than those of tamoxifen-related benign endometrial lesions. The final diagnosis was normal endometrium (n = 36), benign endometrial lesions either EH (n = 17), or EP (n = 16), and endometrial cancer in only 2 patients. CONCLUSIONS: We concluded that DWI helps in detection and characterization of different tamoxifen-related endometrial changes in the premenopausal female patients.

Risk Factors Associated with Endometrial Pathology in Premenopausal Breast Cancer Patients Treated with Tamoxifen.

PURPOSE: To evaluate factors associated with endometrial pathology during tamoxifen use in premenopausal breast cancer (BC) patients. MATERIALS AND METHODS: We reviewed the medical records of premenopausal BC patients treated with tamoxifen who underwent endometrial biopsy with or without hysteroscopy. Clinical characteristics were compared between women with endometrial pathology (endometrial hyperplasia or cancer) and those with normal histology or endometrial polyps. RESULTS: Among 284 endometrial biopsies, endometrial hyperplasia was diagnosed in 7 patients (2.5%), endometrial cancer was diagnosed in 5 patients (1.8%), normal histology was noted in 146 patients (51.4%), and endometrial polyp was present in 114 patients (40.1%). When comparing women with endometrial cancer (n=5) to women with normal histology, abnormal uterine bleeding was more common (p=0.007), and endometrial thickness was greater (p=0.007) in women with endometrial cancer. Chemotherapy for BC was also more common in patients with endometrial cancer (p=0.037). When comparing women with endometrial polyps and those with endometrial hyperplasia or cancer, the presence of abnormal uterine bleeding was more common in patients with endometrial hyperplasia or cancer (p<0.001); however, tamoxifen duration and endometrial thickness did not differ significantly between the two groups. CONCLUSION: In premenopausal BC patients treated with tamoxifen, abnormal uterine bleeding, increased endometrial thickness, and chemotherapy for BC were associated with the occurrence of endometrial cancer. These findings may provide useful information for gynecologic surveillance and counseling during tamoxifen treatment in premenopausal BC patients.

Factors associated with endometrial pathology during tamoxifen therapy in women with breast cancer: a retrospective analysis of 821 biopsies.

PURPOSE: This study evaluated the factors associated with endometrial pathologies during tamoxifen use in women with breast cancer. METHODS: This study analyzed 821 endometrial biopsies from women who received tamoxifen for breast cancer. Clinical characteristics were compared according to the presence of endometrial pathology (atypical hyperplasia and cancer). In addition, patients with endometrial polyps were compared with women with normal histology. RESULTS: Among 821 biopsies, atypical endometrial hyperplasia and cancer were diagnosed in 7 women each. Endometrial polyps were found in 173 women, and 634 women presented normal histology. In comparing women with endometrial pathology (atypical hyperplasia and cancer, n = 14) and those without pathology, parity was significantly lower (P = 0.014) and endometrial thickness was significantly higher (P < 0.001) in women with pathology. In addition, abnormal uterine bleeding was more common in the pathology group (P < 0.001). However, age, body mass index, menopausal status, intrauterine device use, history of diabetes mellitus, and duration of tamoxifen use did not differ according to the presence of pathology. In comparing women with endometrial polyps and those with normal endometrium, significant differences were found in parity (P < 0.001), duration of tamoxifen use (P = 0.003), and endometrial thickness (P < 0.001), but not in the presence of abnormal vaginal bleeding. CONCLUSION: Parity, endometrial thickness, and the presence of abnormal vaginal bleeding, but not age, body mass index, and menopausal status, may be associated with endometrial pathology during tamoxifen use in women with breast cancer. This finding might provide useful information for gynecological surveillance and counseling during tamoxifen treatment.

[Analysis of influencing factors of endometrial disease of patients with breast cancer after operation].

Objective: To study influencing factors which cause the endometrial diseases in patients with breast cancer after operation. Methods: A retrospective study was performed on 212 breast cancer post-operation patients with endometrial diseases between June 2006 and January 2018 in Women's Hospital School of Medicine Zhejiang University to analyse the factors which influenced the endometrial diseases. Results: The abnormal uterine bleeding and endometrial thickness were related to the severity of endometrial disease in patients with breast cancer, and they were independent risk factors for breast cancer patients to have endometrial cancer (P<0.05) . When the diagnostic cut off value of endometrial thickness was ≥0.49 cm, the sensitivity and specificity to endometrial cancer were 78% and 25%, respectively. The average endometrial thickness was (0.56±0.39) cm in patients who were treated by selective estrogen receptor modulator (SERM) after gynecological surgery, which was significantly thicker than that of aromatase inhibitor (AI) group [ (0.33±0.23) cm] and no treatment group [ (0.44±0.28) cm, P<0.05]. The endometrial disease recurrent rate and reoperation rate in SERM group were (26.2%, 14.3%) slightly higher than that of AI group (9.5%, 4.8%) and no treatment group (21.6%, 4.9%), but there were not significant differences (all P>0.05). Conclusions: The clinical symptom of abnormal uterine bleeding and thickening endometrium are risk factors for breast cancer patients to have endometrial cancer. The endometrial thickness has high predictive value for breast cancer patients to diagnose endometrial cancer. The SERM treatment increases the endometrial thickness, recurrent rate and reoperation rate in post-operation patients.

SIX1 Regulates Aberrant Endometrial Epithelial Cell Differentiation and Cancer Latency Following Developmental Estrogenic Chemical Exposure.

Early-life exposure to estrogenic chemicals can increase cancer risk, likely by disrupting normal patterns of cellular differentiation. Female mice exposed neonatally to the synthetic estrogen diethylstilbestrol (DES) develop metaplastic and neoplastic uterine changes as adults. Abnormal endometrial glands express the oncofetal protein sine oculis homeobox 1 (SIX1) and contain cells with basal [cytokeratin (CK)14+/18-] and poorly differentiated features (CK14+/18+), strongly associating SIX1 with aberrant differentiation and cancer. Here, we tested whether SIX1 expression is necessary for abnormal endometrial differentiation and DES-induced carcinogenesis by using Pgr-cre to generate conditional knockout mice lacking uterine Six1 (Six1 d/d). Interestingly, corn oil (CO) vehicle-treated Six1 d/d mice develop focal endometrial glandular dysplasia and features of carcinoma in situ as compared with CO wild-type Six1 (Six1 +/+) mice. Furthermore, Six1 d/d mice neonatally exposed to DES had a 42% higher incidence of endometrial cancer relative to DES Six1 +/+ mice. Although DES Six1 d/d mice had >10-fold fewer CK14+/18- basal cells within the uterine horns as compared with DES Six1 +/+ mice, the appearance of CK14+/18+ cells remained a feature of neoplastic lesions. These findings suggest that SIX1 is required for normal endometrial epithelial differentiation, CK14+/18+ cells act as a cancer progenitor population, and SIX1 delays DES-induced endometrial carcinogenesis by promoting basal differentiation of CK14+/18+ cells. In human endometrial biopsies, 35% of malignancies showed CK14+/18+ expression, which positively correlated with tumor stage and grade and was not present in normal endometrium. IMPLICATIONS: Aberrant epithelial differentiation is a key feature in both the DES mouse model of endometrial cancer and human endometrial cancer. The association of CK14+/18+ cells with human endometrial cancer provides a novel cancer biomarker and could lead to new therapeutic strategies.