Case-control study of postmenopausal hormone replacement therapy and endometrial cancer

Injectable Biomimetic Hydrogel Constructs for Cell-Based Menopausal Hormone Therapy with Reduced Breast Cancer Potential

Hormone replacement therapy (HRT) has been a primary method in menopausal women and patients with ablated ovaries, but safety has been a concern. Cell-based HRT has emerged as an alternative approach without side effects causing pharmaceutical HRT via 3-dimensionally engineered constructs layering ovarian hormone-producing cells. In this study, we applied micro-sized ovarian cell-laden hydrogel beads as an approach to cell-based HRT using a minimally invasive method in the menopausal rat model. Here, we constructed GC/TC-laden microbeads (GTBs; GC, granulosa cell; TC, theca cell) that allow crosstalk between endocrine cells, encapsulating multiple beads for the figuration of the original ovary. We assessed the ovarian hormone production function of GTB through in vitro culture for 90 days. We applied it to a menopausal rat model and confirmed that GTB-injected rats restored their endocrine function, leading to the regeneration of the thinned endometrium and the maintenance of regular estrous cycles in some individuals. Additionally, it was observed to alleviate menopausal symptoms, including body weight gain and osteoporosis. Notably, the GTB-injected rats did not show mammary gland hyperplasia observed in the pharmaceutical HRT groups and exhibited fewer p53- and KI67-positive and an increase in phosphatase and tensin homolog-positive mammary gland epithelial cells compared to pharmaceutical hormone-treated rats. These results suggest that GTB-based HRT could present a lower risk of breast cancer compared to conventional pharmaceutical-HRT use. Our study highlights the potential of cell-based HRT using an injectable artificial ovary, offering a safer alternative for women requiring HRT.

Advances in the study of traditional Chinese medicine affecting bone metabolism through modulation of oxidative stress

Bone metabolic homeostasis is dependent on coupled bone formation dominated by osteoblasts and bone resorption dominated by osteoclasts, which is a process of dynamic balance between bone formation and bone resorption. Notably, the formation of bone relies on the development of bone vasculature. Previous studies have shown that oxidative stress caused by disturbances in the antioxidant system of the whole organism is an important factor affecting bone metabolism. The increase in intracellular reactive oxygen species can lead to disturbances in bone metabolism, which can initiate multiple bone diseases, such as osteoporosis and osteoarthritis. Traditional Chinese medicine is considered to be an effective antioxidant. Cumulative evidence shows that the traditional Chinese medicine can alleviate oxidative stress-mediated bone metabolic disorders by modulating multiple signaling pathways, such as Nrf2/HO-1 signaling, PI3K/Akt signaling, Wnt/β-catenin signaling, NF-κB signaling, and MAPK signaling. In this paper, the potential mechanisms of traditional Chinese medicine to regulate bone me-tabolism through oxidative stress is summarized to provide direction and theoretical basis for future research related to the treatment of bone diseases with traditional Chinese medicine.

Recent advances in the management of postmenopausal women with non-atypical endometrial hyperplasia

Non-atypical endometrial hyperplasia is a benign disease without significant somatic genetic changes. Postmenopausal women with non-atypical endometrial hyperplasia have a significant risk of progression to endometrial cancer and persistent endometrial hyperplasia. Most cases of atypical endometrial hyperplasia in postmenopausal women are treated surgically, including hysterectomy. At present, the treatment of postmenopausal women with non-atypical endometrial hyperplasia is still controversial. Correct and timely diagnosis and treatment are of great significance to prevent progression of the lesion. This study mainly provides an updated synthesis of the literature that investigates the etiology, diagnosis and treatment of postmenopausal women with non-atypical endometrial hyperplasia. As of December 2022, a literature search related to postmenopausal non-atypical endometrial hyperplasia was conducted on the PubMed database. For most postmenopausal patients with non-atypical endometrial hyperplasia, regular re-examination should be performed during conservative treatment. For postmenopausal patients with endometrial cancer risk factors, persistent non-atypical endometrial hyperplasia or progesterone contraindications, hysterectomy and bilateral salpingo-oophorectomy should be the first choice.

Risk factors for endometrial cancer in Black women

PURPOSE

The incidence of endometrial cancer (EC) has been increasing faster among Black women than among other racial/ethnic groups in the United States. Although the mortality rate is nearly twice as high among Black than White women, there is a paucity of literature on risk factors for EC among Black women, particularly regarding menopausal hormone use and severe obesity.

METHODS

We pooled questionnaire data on 811 EC cases and 3,124 controls from eight studies with data on self-identified Black women (4 case-control and 4 cohort studies). We analyzed cohort studies as nested case-control studies with up to 4 controls selected per case. We used logistic regression to estimate multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

We observed a positive association between BMI and EC incidence (P_trend < 0.0001) The OR comparing BMI ≥ 40 vs. < 25 kg/m² was 3.92 (95% CI 2.91, 5.27). Abdominal obesity among those with BMI < 30 kg/m² was not appreciably associated with EC risk (OR 1.21, 95% CI 0.74, 1.99). Associations of reproductive history with EC were similar to those observed in studies of White women. Long-term use of estrogen-only menopausal hormones was associated with an increased risk of EC (≥ 5 years vs. never use: OR 2.08, 95% CI: 1.06, 4.06).

CONCLUSIONS

Our results suggest that the associations of established risk factors with EC are similar between Black and White women. Other explanations, such as differences in the prevalence of known risk factors or previously unidentified risk factors likely underlie the recent increases in EC incidence among Black women.

Endometrial cancer rate in Hormone replacement therapy users with postmenopausal bleeding: Retrospective cohort study

OBJECTIVE

To establish the endometrial cancer detection rate in women using hormone replacement therapy presenting with postmenopausal bleeding.

STUDY DESIGN

Retrospective cohort study. Setting and populationRapid access gynaecology clinic at a tertiary hospital. Women aged under 60 years referred with postmenopausal bleeding.

METHODS

Retrospective study of referrals received between 1 January 2019 and 31 December 2020 including Hormone replacement therapy (HRT) use and histological diagnosis.

MAIN OUTCOME MEASURES

Histological diagnosis of endometrial cancer, borderline ovarian tumour or endometrial intraepithelial neoplasia.

STATISTICAL ANALYSIS

Chi squared test.

RESULTS

1363 women were included. 214 women were using HRT when they experienced PMB and only one of these had endometrial cancer at histology (cancer detection rate 0.47%). 25 of the 1124 women who were not using HRT were diagnosed with endometrial cancer on histology (cancer detection rate 2.18%). Chi squared statistical analysis confirmed this was statistically significant (p value .0156).

CONCLUSIONS

The endometrial cancer detection rate in women aged under 60 years using HRT with PMB is very low. Referral on a two-week wait pathway for suspected cancer diagnosis induces stress and anxiety for the woman and may lead to more invasive initial investigation even though other diagnoses are far more likely. Women aged under 60 years with postmenopausal bleeding that have either commenced HRT or had a change to their preparation within the last 6 months should be seen on a less urgent referral pathway if necessary given the very low probability of endometrial cancer.

Efficacy of Rubus coreanus Miq. and Astragalus membranaceus Bunge Extract for Postmenopausal Syndrome: A Randomised, Double-Blind, Placebo Comparative Clinical Trial

Objectives

The most effective way to improve menopausal symptoms is to supplement deficient oestrogen; however, long-term administration of synthetic oestrogen increases the risk for breast and uterine cancers. Here, we report results from a clinical trial of Rubus coreanus Miq. and Astragalus membranaceus Bunge as agents for improving the menopause syndrome.

Methods

This study was a single-centre, double-blinded, parallel-group, placebo-controlled study. The efficacy of an extract of R. coreanus Miq. and A. membranaceus Bunge was investigated. Participants were females with postmenopausal syndrome in the menopausal or menopausal transition period. The primary endpoint of validation was improvement in the Kupperman index (KI) score of women. The secondary end point was change in the Menopause Rating Scale (MRS) and lipid profile. The participants were randomly allocated at a 1 : 1 ratio into R. coreanus Miq. and A. membranaceus Bunge extract (RCAM) or placebo groups and were administered 2000 mg of the extract or placebo, respectively, daily for 12 weeks. Outcomes were measured at visits 2 (day 0) and 5 (week 12).

Results

The RCAM group demonstrated decreased KI score and MRS compared with the placebo group after 12 weeks. In the safety evaluation, laboratory tests and vital signs demonstrated no clinically significant changes in subjects, and there was no difference in adverse reactions between the groups. The R. coreanus Miq. and A. membranaceus Bunge extract was effective in reducing postmenopausal symptoms in women. Moreover, the extract was found to be safe.

Conclusions

For females with menopausal symptoms in the menopausal transitional and postmenopausal periods, ingestion of the R. coreanus Miq. and A. membranaceus Bunge extract for 12 weeks was effective, as demonstrated by a decrease in KI score and MRS relative to that in the placebo group, and significantly improved the menopausal symptoms.

Spatiotemporal trends in burden of uterine cancer and its attribution to body mass index in 204 countries and territories from 1990 to 2019

BACKGROUND

Uterine cancer is one of the most common female cancers worldwide, with huge heterogeneity in morbidity and mortality. Although a high body-mass index (BMI) has been linked to uterine cancer, systematic reports about the influence of high BMI and its temporal trends are scarce.

METHODS

The annual morbidity, mortality, and disability-adjusted life years (DALYs) of uterine cancer in 204 countries or territories were retrieved from the GBD 2019 study. To reflect trends in disease burden, we also calculated the estimated annual percentage change (EAPC) based on the age-standardized rates of uterine cancer from 1990 to 2019.

RESULTS

The global incident cases of uterine cancer increased 2.3 times from 187,190 in 1990 to 435,040 in 2019. Although the age-standardized incidence rate (ASIR) of uterine cancer increased worldwide from 8.67/100,000 in 1990 to 9.99/100,000 in 2019, the age-standardized death rate (ASDR) and DALY rate decreased during the same period. High socio-demographic index (SDI) countries tended to have a higher ASIR than developing regions, and their increasing trend in ASIR was also more pronounced. The disease was rare before 40 years old, but its risk rose sharply among women aged 50-70. A high BMI was linked to more than one-third of deaths from uterine cancer in 2019.

CONCLUSIONS

The incidence in developed areas was significantly higher than in developing areas and also increased much more rapidly. Elderly females, especially those with a high BMI, have a higher risk of uterine cancer. Therefore, more health resources may be needed to curb the rising burden in specific populations.

Endometrial hyperplasia as a risk factor of endometrial cancer

Endometrial hyperplasia (EH) is the precursor lesion for endometrioid adenocarcinoma of the endometrium (EC), which represents the most common malignancy of the female reproductive tract in industrialized countries. The most important risk factor for the development of EH is chronic exposure to unopposed estrogen. Histopathologically, EH can be classified into EH without atypia (benign EH) and atypical EH/endometrial intraepithelial neoplasia (EIN). Clinical management ranges from surveillance or progestin therapy through to hysterectomy, depending on the risk of progression to or concomitant EC and the patient´s desire to preserve fertility. Multiple studies support the efficacy of progestins in treating both benign and atypical EH. This review summarizes the evidence base regarding risk factors and management of EH. Additionally, we performed a systematic literature search of the databases PubMed and Cochrane Controlled Trials register for studies analyzing the efficacy of progestin treatment in women with EH.

Porphyromonas somerae Invasion of Endometrial Cancer Cells

Recent evidence suggests an association between endometrial cancer and the understudied bacterial species Porphyromonas somerae. This association was demonstrated in previous work that indicated a significantly enriched abundance of P. somerae in the uterine microbiome of endometrial cancer patients. Given the known associations of the Porphyromonas genus and oral cancer, we hypothesized that P. somerae may play a similar pathogenic role in endometrial cancer via intracellular activity. Before testing our hypothesis, we first characterized P. somerae biology, as current background data is limited. These novel characterizations include growth curves in liquid medium and susceptibility tests to antibiotics. We tested our hypothesis by examining growth changes in response to 17β-estradiol, a known risk factor for endometrial cancer, followed by metabolomic profiling in the presence and absence of 17β-estradiol. We found that P. somerae exhibits increased growth in the presence of 17β-estradiol of various concentrations. However, we did not find significant changes in metabolite levels in response to 17β-estradiol. To study direct host-microbe interactions, we used in vitro invasion assays under hypoxic conditions and found evidence for intracellular invasion of P. somerae in endometrial adenocarcinoma cells. We also examined these interactions in the presence of 17β-estradiol but did not observe changes in invasion frequency. Invasion was shown using three lines of evidence including visualization via differential staining and brightfield microscopy, increased frequency of bacterial recovery after co-culturing, and in silico methods to detail relevant genomic and transcriptomic components. These results underscore potential intracellular phenotypes of P. somerae within the uterine microbiome. Furthermore, these results raise new questions pertaining to the role of P. somerae in the progression of endometrial cancer.

Pregnancy outcomes and risk of endometrial cancer: A pooled analysis of individual participant data in the Epidemiology of Endometrial Cancer Consortium

A full-term pregnancy is associated with reduced endometrial cancer risk; however, whether the effect of additional pregnancies is independent of age at last pregnancy is unknown. The associations between other pregnancy-related factors and endometrial cancer risk are less clear. We pooled individual participant data from 11 cohort and 19 case-control studies participating in the Epidemiology of Endometrial Cancer Consortium (E2C2) including 16 986 women with endometrial cancer and 39 538 control women. We used one- and two-stage meta-analytic approaches to estimate pooled odds ratios (ORs) for the association between exposures and endometrial cancer risk. Ever having a full-term pregnancy was associated with a 41% reduction in risk of endometrial cancer compared to never having a full-term pregnancy (OR = 0.59, 95% confidence interval [CI] 0.56-0.63). The risk reduction appeared the greatest for the first full-term pregnancy (OR = 0.78, 95% CI 0.72-0.84), with a further ~15% reduction per pregnancy up to eight pregnancies (OR = 0.20, 95% CI 0.14-0.28) that was independent of age at last full-term pregnancy. Incomplete pregnancy was also associated with decreased endometrial cancer risk (7%-9% reduction per pregnancy). Twin births appeared to have the same effect as singleton pregnancies. Our pooled analysis shows that, while the magnitude of the risk reduction is greater for a full-term pregnancy than an incomplete pregnancy, each additional pregnancy is associated with further reduction in endometrial cancer risk, independent of age at last full-term pregnancy. These results suggest that the very high progesterone level in the last trimester of pregnancy is not the sole explanation for the protective effect of pregnancy.

Porphyromonas somerae Invasion of Endometrial Cancer Cells

Recent evidence suggests an association between endometrial cancer and the understudied bacterial species Porphyromonas somerae. This association was demonstrated in previous work that indicated a significantly enriched abundance of P. somerae in the uterine microbiome of endometrial cancer patients. Given the known associations of the Porphyromonas genus and oral cancer, we hypothesized that P. somerae may play a similar pathogenic role in endometrial cancer via intracellular activity. Before testing our hypothesis, we first characterized P. somerae biology, as current background data is limited. These novel characterizations include growth curves in liquid medium and susceptibility tests to antibiotics. We tested our hypothesis by examining growth changes in response to 17β-estradiol, a known risk factor for endometrial cancer, followed by metabolomic profiling in the presence and absence of 17β-estradiol. We found that P. somerae exhibits increased growth in the presence of 17β-estradiol of various concentrations. However, we did not find significant changes in metabolite levels in response to 17β-estradiol. To study direct host-microbe interactions, we used in vitro invasion assays under hypoxic conditions and found evidence for intracellular invasion of P. somerae in endometrial adenocarcinoma cells. We also examined these interactions in the presence of 17β-estradiol but did not observe changes in invasion frequency. Invasion was shown using three lines of evidence including visualization via differential staining and brightfield microscopy, increased frequency of bacterial recovery after co-culturing, and in silico methods to detail relevant genomic and transcriptomic components. These results underscore potential intracellular phenotypes of P. somerae within the uterine microbiome. Furthermore, these results raise new questions pertaining to the role of P. somerae in the progression of endometrial cancer.

Menopausal Hormone Therapy and Risk of Endometrial Cancer: A Systematic Review

Background: Menopausal hormone therapy (MHT) is an appropriate treatment for women with the climacteric syndrome. The estrogen component of MHT effectively alleviates climacteric symptoms but also stimulates the endometrium and thus may increase the risk of endometrial cancer (EC). Materials and Methods: We performed a systematic literature search of the databases PubMed and Cochrane Central Register of Controlled Trials to identify controlled and uncontrolled clinical trials reporting on the prevalence and/or incidence of EC among women using MHT. Results: 31 publications reporting on 21,306 women with EC diagnosed during or after MHT were identified. A significantly reduced risk of EC among continuous-combined (cc)MHT users with synthetic progestins (SPs) was demonstrated in 10/19 studies with odds ratios (ORs)/hazard ratios (HRs) between 0.24 and 0.71. Only one study documented an increased risk of EC among long-term users (≥10 years), not confirmed in three other sub-group analyses of women with ≥6, ≥5, and >10 years of ccMHT use. A significantly increased risk of EC among users of sequential-combined (sc)MHT with SPs was demonstrated in 6/12 studies with ORs/HRs between 1.38 and 4.35. Number of days of progestin per month was a significant modulator of EC risk. A decreased risk of EC was seen in obese women. Two studies documented an increased risk of EC among users of cc/scMHT with micronized progesterone. A significantly increased risk of EC among estrogen-only MHT users was demonstrated in 9/12 studies with ORs/HRs between 1.45 and 4.46. The adverse effect of estrogen-only MHT was greatest among obese women. Conclusion: ccMHT with SPs reduces the risk of EC, whereas estrogen-only MHT increases the risk. scMHT with SPs and cc/scMHT with micronized progesterone increase the risk of EC depending on type of progestin, progestin dosage, and duration of MHT use.

Changes in Uterine Cancer Incidence Rates in Egypt

Background

Uterine cancer is one of the top-ranking cancers in women with wide international variations in incidence rates. Developed countries have higher incidence rates than the developing countries. Egypt has significantly lower incidence of uterine cancer than other countries in the Middle East. This study aimed at verifying the incidence rate of uterine cancer and characterizing the demographic and clinical profiles of patients residing in the Gharbiah province in the Nile delta region of Egypt.

Methods

Data from 660 uterine cancer patients diagnosed during the period of 1999 to 2010 were abstracted from the Gharbiah Cancer Registry, the only population-based registry in Egypt. The data included age, marital status, number of children, residence, smoking, occupation, date and basis of diagnosis, tumor topography, morphology, stage and grade, and treatment. Crude rate, age-standardized rate (ASR), and age-specific rate were calculated and associated with demographic and clinical characteristics of patients.

Results

The study confirmed the low ASR of uterine cancer in Egypt, (4.1 per 100,000 (95% CI: 3.8-4.4)). The incidence rate increased significantly over the 12-year period. The crude rate (CR) was 1.95, 95% CI (1.64-2.25) in 1999-2002; 2.9, 95% CI (2.5-3.2) in 2003-2006; and 3.5, 95% CI (3.1-3.9) in 2007-2010. The rate ratio was 1.5, 95% CI (1.2-1.8) in 2003-2006 and 1.8, 95% CI (1.5-2.2) in 2007-2010 compared to 1999-2002. The majority of patients (83%) were postmenopausal with the highest age-specific rate in the 60-69-year age group (22.07 per 100,000 (95% CI: 19.3-25.2). The majority of patients were diagnosed at early stages (60% localized and 5% regional), had adenocarcinoma (68%), and resided in urban areas (54%).

Conclusions

The study confirmed the low incidence rate of uterine cancer in the Gharbiah province of Egypt and significant increase in incidence in recent years. Future studies should focus on verifying the possible effect of hysterectomy on lowering the incidence, the factors related to the changes in rates between rural and urban areas, and the possible impact of nutritional and epidemiologic transitions on the increasing rates.

Exogenous Hormone Use and Endometrial Cancer in U.S. Black Women

Background: Although endometrial cancer risk differs among white and black women, few data on its associations with exogenous hormone use in the latter group are available. Studies have reported lower endometrial cancer risk among users of oral contraceptives (OCs), but higher risk among users of estrogen-only female menopausal hormones (FMHs). Evidence for the risk among estrogen plus progestin FMHs users is equivocal.Methods: We followed 47,555 Black Women's Health Study participants with an intact uterus from 1995 through 2013. Data on exogenous hormone use, covariates, and endometrial cancer were obtained biennially. Self-reported incident cases of endometrial cancer were confirmed by medical records or cancer registries whenever possible. We estimated incidence rate ratios (IRRs) and 95% confidence intervals (CIs) using Cox proportional hazards regression.Results: We observed 300 endometrial cancer cases during 689,546 person-years of follow-up. Compared with never use, ≥10 years' duration of OC use was associated with lower risk (multivariable IRR = 0.45, 95% CI, 0.27-0.74), but risk was higher among current users of estrogen-only (IRR = 3.78, 95% CI, 1.69-8.43) and estrogen plus progestin FMH (IRR = 1.55, 95% CI, 0.78-3.11). Risk was not increased among former users of estrogen-only (IRR = 0.87, 95% CI, 0.44-1.72) or estrogen plus progestin FMH (IRR = 0.63, 95% CI, 0.36-1.09).Conclusions: Current use of estrogen-only and estrogen plus progestin FMH was associated with increased risk of endometrial cancer. Risk appeared lower among former users of estrogen plus progestin FMH. Long-term OC use was associated with reduced risk.Impact: Our results are generally consistent with those among white women. Cancer Epidemiol Biomarkers Prev; 27(5); 558-65. ©2018 AACR.

Protective effect of Rhizoma Dioscoreae extract against alveolar bone loss in ovariectomized rats via regulation of IL-6/STAT3 signaling

The aim of the present study was to assess the effectiveness of Rhizoma Dioscoreae extract (RDE) on preventing rat alveolar bone loss induced by ovariectomy (OVX), and to determine the role of interleukin-6 (IL-6)/signal transducer and activator of transcription 3 (STAT3) signaling pathway in this effect. Female Wistar rats were subjected to OVX or sham surgery. The rats that had undergone OVX were treated with RDE (RDE group), vehicle (OVX group) or 17β-estradiol subcutaneous injection (E2 group). Subsequently, bone metabolic activity was assessed by analyzing 3-D alveolar bone construction, bone mineral density, as well as the plasma biomarkers of bone turnover. The gene expression of alveolar bone in the OVX and RDE groups was evaluated by IL-6/STAT3 signaling pathway polymerase chain reaction (PCR) arrays, and differentially expressed genes were determined through reverse transcription-quantitative PCR. The inhibitory effect of RDE on alveolar bone loss in the OVX group was demonstrated in the study. In comparison with the OVX group, the RDE group exhibited 19 downregulated genes and 1 upregulated gene associated with the IL-6/STAT3 signaling pathway in alveolar bone. Thus, RDE was shown to relieve OVX-induced alveolar bone loss in rats, an effect which was likely associated with decreased abnormal bone remodeling via regulation of the IL-6/STAT3 signaling pathway.

Breastfeeding and Endometrial Cancer Risk: An Analysis From the Epidemiology of Endometrial Cancer Consortium

OBJECTIVE

To investigate the association between breastfeeding and endometrial cancer risk using pooled data from 17 studies participating in the Epidemiology of Endometrial Cancer Consortium.

METHODS

We conducted a meta-analysis with individual-level data from three cohort and 14 case-control studies. Study-specific odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for the association between breastfeeding and risk of endometrial cancer using multivariable logistic regression and pooled using random-effects meta-analysis. We investigated between-study heterogeneity with I  and Q statistics and metaregression.

RESULTS

After excluding nulliparous women, the analyses included 8,981 women with endometrial cancer and 17,241 women in a control group. Ever breastfeeding was associated with an 11% reduction in risk of endometrial cancer (pooled OR 0.89, 95% CI 0.81-0.98). Longer average duration of breastfeeding per child was associated with lower risk of endometrial cancer, although there appeared to be some leveling of this effect beyond 6-9 months. The association with ever breastfeeding was not explained by greater parity and did not vary notably by body mass index or histologic subtype (grouped as endometrioid and mucinous compared with serous and clear cell).

CONCLUSION

Our findings suggest that reducing endometrial cancer risk can be added to the list of maternal benefits associated with breastfeeding. Ongoing promotion, support, and facilitation of this safe and beneficial behavior might therefore contribute to the prevention of this increasingly common cancer.

Hypertension and the risk of endometrial cancer: a systematic review and meta-analysis of case-control and cohort studies

A history of hypertension has been associated with increased risk of endometrial cancer in several studies, but the results have not been consistent. We conducted a systematic review and meta-analysis of case-control and cohort studies to clarify the association between hypertension and endometrial cancer risk. PubMed and Embase databases were searched up to 27^th of February 2016. Prospective and case-control studies which reported adjusted relative risk estimates and 95% confidence intervals of endometrial cancer associated with a hypertension diagnosis were included. Summary relative risks were estimated using a random effects model. Nineteen case-control studies and 6 cohort studies were included. The summary RR was 1.61 (95% CI: 1.41–1.85, I² = 86%) for all studies, 1.73 (95% CI: 1.45–2.06, I² = 89%) for case-control studies and 1.32 (95% CI: 1.12–1.56, I² = 47%) for cohort studies. The association between hypertension and endometrial cancer was weaker, but still significant, among studies with adjustment for smoking, BMI, oral contraceptive use, and parity, compared to studies without such adjustment. This meta-analysis suggest an increased risk of endometrial cancer among patients with hypertension, however, further studies with more comprehensive adjustments for confounders are warranted to clarify the association.

Effect of icariin on fracture healing in an ovariectomized rat model of osteoporosis

Osteoporosis is frequently asymptomatic, presenting a significant clinical and economic burden, particularly following an osteoporosis-associated fracture. Icariin has been reported to inhibit osteoporosis in vitro, and the present study investigated whether icariin also promoted bone fracture healing in ovariectomized osteoporotic (OVX) rats in vivo. A total of 30 female rats were randomly divided into three groups (n=10 per group): i) Sham surgery; ii) OVX; and iii) OVX with icariin (OVX + ICA) groups. At 3 months after the ovariectomy, a unilateral cross-tibia fracture was made at the proximal right tibia. Animals were then sacrificed after 5 weeks of oral treatment. X-rays were taken at 1 week, 3 weeks and 5 weeks of treatment, and dual energy X-ray absorptiometry was used to measure the bone mineral density (BMD). Changes to the osteocalcin (BGLAP), alkaline phosphatase (ALP), tartrate-resistant acid phosphatase (TRAP) and estradiol levels in blood were measured. Callus formation and bone union were observed, the BMD was significantly higher and the BGLAP, ALP and TRAP levels were reduced, but no significant increase was observed in the blood estradiol level in the OVX + ICA group compared with the OVX group. The present findings indicate that icariin has potential as a novel alternative therapeutic agent for fracture healing in postmenopausal osteoporosis.

Antiosteoporotic effects of Alpinia officinarum Hance through stimulation of osteoblasts associated with antioxidant effects

BACKGROUND/OBJECTIVE

Alpinia officinarum Hance (AOH) is a traditional herbal medicine specific to south China and serves as a civil medication application of an antioxidant. Growing evidence demonstrates that antioxidants are beneficial for the treatment of osteoporosis. This study was designed to investigate the antiosteoporotic effects of total extracts from AOH in ovariectomised (OVX) rats and the different fractions in AOH on primary osteoblasts activities.

METHODS

The total extract of AOH was extracted by refluxing using 95% ethanol, then the five fractions (F1-F5) were separated from AOH using thin-layer chromatography according to polarity from high to low, and the galangin content was determined using high performance liquid chromatography. In an in vivo study, 36 4-month-old female Sprague-Dawley rats were used as a Sham-operated group, OVX with vehicle (OVX), OVX with epimedium flavonoids (EF, 150 mg/kg/d), and OVX with AOH (AOH, 300 mg/kg/d), respectively. Daily oral administration started on Day 3 after OVX and lasted for 12 weeks. In the in vitro study, primary osteoblasts were incubated with AOH, galangin, and five different fractions (F1-F5) with or without hydrogen peroxide (H2O2), respectively.

RESULTS

Treatment with AOH significantly attenuated osteopenia accompanied by a decreased percentage of osteoclast perimeter and bone formation rate per unit of bone surface, enhanced the bone strength, and prevented the deterioration of trabecular microarchitecture associated with a decrease in biochemical parameters of oxidative stress. Furthermore, treatment with AOH, F3, F4, and galangin increased cell viability, differentiation, and mineralisation in osteoblasts with or without H2O2 and rescued the deleterious effects of H2O2 on cell apoptosis and intracellular reactive oxygen species level. The effects on osteoblast formation were highly aligned with the amounts of flavonoids within AOH.

CONCLUSION

These data demonstrate that ethanol extracts from AOH significantly reverse bone loss, partially by increasing bone formation, and by suppressing bone resorption associated with antioxidant effects, suggesting that AOH can be developed as a promising agent for the prevention and treatment of osteoporosis.

Continuous Combined Estrogen Plus Progestin and Endometrial Cancer: The Women's Health Initiative Randomized Trial

BACKGROUND

While progestin addition to estrogen mitigates endometrial cancer risk, the magnitude of the effect on incidence, specific endometrial cancer histologies, and endometrial cancer mortality remains unsettled. These issues were assessed by analyses after extended follow-up of the Women's Health Initiative (WHI) randomized clinical trial evaluating continuous combined estrogen plus progestin use.

METHODS

The WHI enrolled 16 608 postmenopausal women into a randomly assigned, double-blind, placebo-controlled trial. Women age 50 to 79 years with intact uteri with normal endometrial biopsy at entry were randomly assigned to once-daily 0.625 mg conjugated equine estrogen plus 2.5mg medroxyprogesterone acetate (n = 8506) as a single pill or matching placebo (n = 8102). Follow-up beyond the original trial completion date required reconsent, obtained from 12 788 (83%) of surviving participants. Analyses were by intent-to-treat. All statistical tests were two-sided.

RESULTS

After 5.6 years' median intervention and 13 years' median cumulative follow-up, there were fewer endometrial cancers in the combined hormone therapy compared with the placebo group (66 vs 95 case patients, yearly incidence, 0.06% vs 0.10%; hazard ratio [HR] = 0.65, 95% confidence interval [CI] = 0.48 to 0.89, P = .007). While there were somewhat fewer endometrial cancers during intervention (25 vs 30, respectively; HR = 0.77, 95% CI = 0.45 to 1.31), the difference became statistically significant postintervention (41 vs 65, respectively; HR = 0.59, 95% CI = 0.40 to 0.88, P = .008), but hazard ratios did not differ between phases (P difference = .46). There was a statistically nonsignificant reduction in deaths from endometrial cancer in the estrogen plus progestin group (5 vs 11 deaths, HR = 0.42, 95% CI = 0.15 to 1.22).

CONCLUSION

In postmenopausal women, continuous combined estrogen plus progestin decreases endometrial cancer incidence.

Endometrial cancer and oral contraceptives: an individual participant meta-analysis of 27 276 women with endometrial cancer from 36 epidemiological studies

BACKGROUND

Oral contraceptives are known to reduce the incidence rate of endometrial cancer, but it is uncertain how long this effect lasts after use ceases, or whether it is modified by other factors.

METHODS

Individual participant datasets were sought from principal investigators and provided centrally for 27 276 women with endometrial cancer (cases) and 115 743 without endometrial cancer (controls) from 36 epidemiological studies. The relative risks (RRs) of endometrial cancer associated with oral contraceptive use were estimated using logistic regression, stratified by study, age, parity, body-mass index, smoking, and use of menopausal hormone therapy.

FINDINGS

The median age of cases was 63 years (IQR 57-68) and the median year of cancer diagnosis was 2001 (IQR 1994-2005). 9459 (35%) of 27 276 cases and 45 625 (39%) of 115 743 controls had ever used oral contraceptives, for median durations of 3·0 years (IQR 1-7) and 4·4 years (IQR 2-9), respectively. The longer that women had used oral contraceptives, the greater the reduction in risk of endometrial cancer; every 5 years of use was associated with a risk ratio of 0·76 (95% CI 0·73-0·78; p<0·0001). This reduction in risk persisted for more than 30 years after oral contraceptive use had ceased, with no apparent decrease between the RRs for use during the 1960s, 1970s, and 1980s, despite higher oestrogen doses in pills used in the early years. However, the reduction in risk associated with ever having used oral contraceptives differed by tumour type, being stronger for carcinomas (RR 0·69, 95% CI 0·66-0·71) than sarcomas (0·83, 0·67-1·04; case-case comparison: p=0·02). In high-income countries, 10 years use of oral contraceptives was estimated to reduce the absolute risk of endometrial cancer arising before age 75 years from 2·3 to 1·3 per 100 women.

INTERPRETATION

Use of oral contraceptives confers long-term protection against endometrial cancer. These results suggest that, in developed countries, about 400 000 cases of endometrial cancer before the age of 75 years have been prevented over the past 50 years (1965-2014) by oral contraceptives, including 200 000 in the past decade (2005-14).

FUNDING

Medical Research Council, Cancer Research UK.

The protective effect of Rhizoma Dioscoreae extract against alveolar bone loss in ovariectomized rats via regulating Wnt and p38 MAPK signaling

AIM

The aim of this study was to evaluate the osteoprotective effect of aqueous Rhizoma Dioscoreae extract (RDE) on the alveolar bone of rats with ovariectomy-induced bone loss.

METHODS

Female Wistar rats were subjected to either ovariectomy or a sham operation (SHAM). The ovariectomized (OVX) rats were treated with vehicle (OVX) or RDE by oral gavage or with 17β-estradiol (E2) subcutaneously. After treatments, the bone mineral density (BMD), the three-dimensional bone architecture of the alveolar bone and the plasma biomarkers of bone turnover were analyzed to assess bone metabolism, and the histomorphometry of the alveolar bone was observed. Microarrays were used to evaluate gene expression profiles in alveolar bone from RDE-treated and OVX rats. The differential expression of genes was further analyzed using Ingenuity Pathway Analysis (IPA). The key findings were verified using real-time quantitative RT-PCR (qRT-PCR).

RESULTS

Our results showed that RDE inhibited alveolar bone loss in OVX rats. Compared to the OVX rats, the RDE-treated rats showed upregulated expression levels of 207 genes and downregulated expression levels of 176 genes in the alveolar bone. The IPA showed that several genes had the potential to code for proteins that were involved in the Wnt/β-catenin signaling pathway (Wnt7a, Fzd2, Tcf3, Spp1, Frzb, Sfrp2 and Sfrp4) and the p38 MAPK signaling pathway (Il1rn and Mapk14).

CONCLUSION

These experiments revealed that RDE could inhibit ovariectomy-induced alveolar bone loss in rats. The mechanism of this anti-osteopenic effect in alveolar bone may be involved in the reduced abnormal bone remodeling, which is associated with the modulation of the Wnt/β-catenin and the p38 MAPK signaling pathways via gene regulation.

High-dose diosgenin reduces bone loss in ovariectomized rats via attenuation of the RANKL/OPG ratio

The aim of this study was to evaluate effect of diosgenin (DG) on rats that had osteoporosis-like features induced by ovariectomy (OVX). Seventy-two six-month-old female Wistar rats were subjected to either ovariectomy (n = 60) or Sham operation (SHAM group, n = 12). Beginning at one week post-ovariectomy, the OVX rats were treated with vehicle (OVX group, n = 12), estradiol valerate (EV group, n = 12), or DG at three doses (DG-L, -M, -H group, n = 12, respectively). After a 12-week treatment, administration of EV or DG-H inhibited OVX-induced weight gain, and administration of EV or DG-H or DG-M had a significantly uterotrophic effect. Bone mineral density (BMD) and indices of bone histomorphometry of tibia were measured. Levels of protein and mRNA expression of osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-B ligand (RANKL) in tibia were evaluated by immunohistochemistry and in situ hybridization. Our results show that DG at a high dose (DG-H) had a significant anti-osteoporotic effect compared to OVX control. DG-H treatment down-regulated expression of RANKL and up-regulated expression of OPG significantly in tibia from OVX rats compared to control, and thus lowered the RANKL/OPG ratio. This suggests that the anti-osteoporotic effect of DG might be associated with modulating the RANKL/OPG ratio and DG had potential to be developed as alternative therapeutic agents of osteoporosis induced by postmenopause.

Endometrial cancer after endometrial ablation vs medical management of abnormal uterine bleeding

STUDY OBJECTIVE

To investigate whether endometrial ablation is associated with increased risk or delayed diagnosis of endometrial cancer compared with medical management of abnormal uterine bleeding.

DESIGN

Multi-centered retrospective cohort study (Canadian Task Force classification II-2).

SETTING

The study was performed using data from The Health Improvement Network, a representative population-based cohort of patients in 495 outpatient general practitioner practices in the United Kingdom.

PATIENTS

Women aged >25 years with abnormal uterine bleeding diagnosed between June 1994 and September 2010.

INTERVENTIONS

Endometrial ablation, medical management, or both.

MEASUREMENTS AND MAIN RESULTS

A total of 234 721 women met study inclusion and exclusion criteria, 4776 of whom underwent endometrial ablation and the remaining 229 945 received medical management. Cox models compared endometrial cancer rates between ablation and medical management groups using hazard ratios. To investigate a possible diagnostic delay, the median time from bleeding diagnosis to endometrial cancer diagnosis in women in whom endometrial cancer developed was compared using the Mann-Whitney U test. All statistical tests were 2-tailed, with α = .05. During a median observation period of 4.07 years (interquartile range [IQR], 1.88-7.17), endometrial cancer developed in 3 women in the ablation group and 601 women in the medical management group (ablation hazard ratio, 0.45; 95% confidence interval, 0.15-1.40; p = .17). Median time to diagnosis was 237 in the ablation group, and 299 days in the medical management group (ablation IQR, 155-1350; medical management IQR, 144-1133.5; p = .99). Adjusted and sensitivity analyses did not change the results.

CONCLUSIONS

No difference was observed in endometrial cancer rates, and there was no delay in diagnosis when comparing endometrial ablation vs medical management. Further studies are needed to investigate the effect of previous ablation exposure on histology or cancer stage at manifestation of endometrial cancer.

Menopausal hormone therapy and risk of endometrial cancer

Endometrial cancer is clearly a hormonally responsive tumor, with a critical role played by estrogens unopposed by progestins. Numerous epidemiologic studies have shown substantial risk increases associated with use of unopposed estrogens, especially among thin women. This risk, however, can be reduced if progestins are added to the therapy. The manner in which progestins are prescribed is a critical determinant of risk. Most studies show that women who have ever used progestins continuously (>25 days/months) are at somewhat reduced risk relative to non-users (meta-analysis relative risk, RR, based on observational studies=0.78, 95 confidence intervals, CI, 0.72-0.86). The reduced risk in greatest among heavy women. In contrast, women who have ever used progestins sequentially for <10 days each month are at increased risk, with meta-analysis results showing on overall RR of 1.76 (1.51-2.05); in contrast, progestins given for 10-24 days/month appear unrelated to risk (RR=1.07, 0.92-1.24). These risks were based on varying patterns of usage, with little information available regarding how endometrial cancer risk is affected by duration of use, type and/or dose of estrogen or progestin, or mode of administration. Effects may also vary by clinical characteristics (e.g., differences for Type I vs. II tumors). Further resolution of many of these relationships may be dependent on pooling data from multiple studies to derive sufficient power for subgroups of users. With changing clinical practices, it will be important for future studies to monitor a wide range of exposures and to account for divergent effects of different usage patterns. This article is part of a Special Issue entitled 'Menopause'.

Long-term alcohol intake and risk of endometrial cancer in the Nurses' Health Study, 1980-2010

BACKGROUND

Previous epidemiologic studies have shown inconsistent results for the association between alcohol intake and endometrial cancer risk. Most of the studies, however, assessed alcohol intake after cancer diagnosis, or measured alcohol intake at baseline only.

METHODS

We prospectively examined the association between alcohol intake and endometrial cancer risk in the Nurses' Health Study with 68 067 female participants aged 34-59 years in 1980. Alcohol intake was measured several times with validated dietary questionnaires. We calculated cumulative average alcohol intake to represent long-term intakes of individual subjects. Using Cox proportional hazards models, we estimated incidence rate ratios (RRs) and 95% confidence intervals (CIs) for endometrial cancer risk after controlling for several risk factors simultaneously.

RESULTS

We identified a total of 794 invasive endometrial adenocarcinoma from 1980 to 2010. We found an inverse association among alcohol drinkers (multivariable RR=0.81; 95% CI: 0.68-0.96) compared with nondrinkers. Women with light alcohol intake of <5 g per day (∼half drink per day) had a 22% lower risk of endometrial cancer (multivariable RR=0.78; 95% CI: 0.66-0.94). Higher intake of alcohol, however, did not provide additional benefits against endometrial cancer: multivariable RRs for 5-14.9 g (∼1 drink), 15-29.9 g (∼2 drinks), or ≥ 30 g (≥ 2 drinks) versus 0 g per day were 0.88, 0.83, and 0.78 (95% CI: 0.49-1.25), respectively. The lower risk among drinkers (∼half drink per day) appeared to be stronger for obese women, but no significant interaction by body mass index was found.

CONCLUSIONS

This study provides prospective evidence for an inverse association between light alcohol intake (∼half drink per day) in the long term and endometrial cancer risk, but above that level no significant association was found.

Treatment with Rhizoma Dioscoreae extract has protective effect on osteopenia in ovariectomized rats

The aims of this study were to evaluate the osteoprotective effect of aqueous extract from Rhizoma Dioscoreae (RDE) on rats with ovariectomy- (OVX-) induced osteopenia. Our results show that RDE could inhibit bone loss of OVX rats after a 12-week treatment. The microarray analysis showed that 68 genes were upregulated and that 100 genes were downregulated in femurs of the RDE group rats compared to those in the OVX group. The Ingenuity Pathway Analysis (IPA) showed that several downregulated genes had the potential to code for proteins that were involved in the Wnt/ β -catenin signaling pathway (Sost, Lrp6, Tcf7l2, and Alpl) and the RANKL/RANK signaling pathway (Map2k6 and Nfatc4). These results revealed that the mechanism for an antiosteopenic effect of RDE might lie in the synchronous inhibitory effects on both the bone formation and the bone resorption, which is associated with modulating the Wnt/ β -catenin signaling and the RANKL/RANK signaling.

Case-control study of lifetime alcohol consumption and endometrial cancer risk

Purpose

Alcohol consumption is hypothesized to increase the risk of endometrial cancer by increasing circulating estrogen levels. This study sought to investigate the association between lifetime alcohol consumption and endometrial cancer risk.

Methods

We recruited 514 incident endometrial cancer cases and 962 frequency age-matched controls in this population-based case–control study in Alberta, Canada, from 2002 to 2006. Participants completed in-person interviews querying lifetime alcohol consumption and other relevant health and lifestyle factors. Participants reported the usual number of drinks of beer, wine, and liquor consumed; this information was compiled for each drinking pattern reported over the lifetime to estimate average lifetime exposure to alcohol.

Results

Lifetime average alcohol consumption was relatively low (median intake: 3.9 g/day for cases, 4.9 g/day for controls). Compared with lifetime abstainers, women consuming >2.68 and ≤8.04 g/day alcohol and >8.04 g/day alcohol on average over the lifetime showed 38 and 35 % lower risks of endometrial cancer, respectively (p trend = 0.023). In addition, average lifetime consumption of all types of alcohol was associated with decreased risks. There was no evidence for effect modification by body mass index, physical activity, menopausal status, and hormone replacement therapy use combined and effects did not differ by type of endometrial cancer (type I or II).

Conclusion

This study provides epidemiologic evidence for an inverse association between relatively modest lifetime average alcohol consumption (approximately 1/4 to 1/2 drink/day) and endometrial cancer risk. The direction of this relation is consistent with previous studies that examined similar levels of alcohol intake.

Therapeutic effect of aqueous extract from Ecliptae herba on bone metabolism of ovariectomized rats

OBJECTIVE

Ecliptae herba (EH) has long been used in China to strengthen bones. Accumulating evidence indicates that EH may have antiosteoporotic effects. The aim of this study was to evaluate the effects of aqueous EH extract (EHE) on rats that had osteoporosis-like features induced by ovariectomy, using aqueous Fructus Ligustri Lucidi extract as positive control agent.

METHODS

Three-month-old female rats that underwent ovariectomy were treated with EHE (1.4 g/kg per day). After 12 weeks, bone mineral density and bone histomorphometric indices of tibiae were measured. Protein and messenger RNA expressions of osteoprotegerin and receptor activator of nuclear factor κ-B ligand (RANKL) in tibiae were evaluated by immunohistochemistry and in situ hybridization. In addition, serum concentrations of osteocalcin, interleukin-1β, interleukin-6 (IL-6), calcitonin (CT), and parathyroid hormone were determined by enzyme-linked immunosorbent assay.

RESULTS

EHE treatment prevented body weight gain and loss of uterine wet weight in ovariectomized rats. It remarkably increased bone mass in ovariectomized rats compared with ovariectomized controls. EHE treatment significantly down-regulated RANKL expression in tibiae from ovariectomized rats compared with controls; however, it had no significant effect on osteoprotegerin expression. In addition, EHE treatment significantly reduced serum IL-6 levels and remarkably increased CT levels but had no effect on parathyroid hormone.

CONCLUSIONS

EHE increases bone mass in ovariectomized rats by inhibiting bone loss: down-regulated RANKL expression in tibiae and IL-6 level in serum, and up-regulated CT level in serum. This suggests that EHE may be developed as an alternative therapeutic agent for osteoporosis induced by postmenopause.

Association of progesterone receptor gene (PGR) variants and breast cancer risk in African American women

Prolonged exposure to combined hormone replacement therapy (estrogen plus progestin) increases a woman's risk of breast cancer, whereas estrogen-only hormone replacement therapy does not. This suggests that progesterone may play a role in breast carcinogenesis. Association studies have reported inconsistent relationships between progesterone receptor gene variants and breast cancer. A population-based case-control study in three counties of the Philadelphia Metropolitan area was undertaken. We evaluated 8 PGR candidate SNPs and 18 PGR tagging SNPS in 487 breast cancer cases and 843 controls using multivariable logistic regression with adjustment for combined hormone replacement therapy use. Separate analyses were conducted for European Americans (EA: 399 cases, 490 controls) and African Americans (AA: 88 cases, 353 controls). In EAs, no significant associations were observed with the investigated PGR variants. In AAs, two tagging SNPs (rs590688 and rs10895054) were statistically significantly associated with breast cancer. For rs590688, each addition of the C allele was protective compared to the G allele (OR = 0.56, 95 % CI 0.39-0.82, p value 0.003, corrected p value 0.03). For rs10895054, each addition of the T allele increased the risk of breast cancer compared to the A allele nearly threefold (OR = 2.9, 95 % CI 1.47-6.02, p value 0.002, corrected p value 0.04). Three haplotype blocks, all containing rs590688, were found to be significantly associated with breast cancer risk. Environmental exposures, namely parity and obesity modified the effect of both SNPs on breast cancer risk in EA. This is the first study to find an association between two PGR variants and breast cancer in AA women. These results suggest that studies of PGR variants in other non-White populations may reveal additional cancer associations of interest.

Risk-Benefit Analysis of Combination vs. Unopposed HRT in Post-Menopausal Women

Many trials on the use of hormone replacement therapy (HRT) have provided contradictory results on its risks and benefits in post-menopausal women. The use of HRT declined globally following publication of the first data from the Women’s Health Initiative (WHI) trial in 2002, with the revelation that there was an increased risk of breast cancer and coronary heart disease (CHD) in postmenopausal women taking HRT. Following this, other leading studies published results that were consistent with these findings, which reduced enthusiasm for HRT use. However, recent publications from the International Menopause Society indicate that HRT is the first-line and most effective treatment for menopausal symptoms. Moreover, when the full results of the WHI trial were subsequently published, it appeared that HRT may confer benefits for CHD prevention below age 60. The statements from the British Menopause Society and the International Menopause Society (IMS) published in 2008 also supported this opinion. These revelations renew interest in HRT use. This paper analyzes the effects of combination versus unopposed HRT on osteoporosis, breast and CHD, endometrial cancer induction, venous thromboembolic disease, lipids and lipoproteins, neuroprotection, and cognitive function in post-menopausal women.

Is estrogen plus progestin menopausal hormone therapy safe with respect to endometrial cancer risk?

Given the strong link between use of unopposed estrogens and development of endometrial cancers, estrogens are usually prescribed with a progestin, particularly for women with intact uteri. Some studies suggest that sequential use of progestins may increase risk; however, the moderating effects of usage patterns or patient characteristics, including body mass index (BMI), are unknown. We evaluated menopausal hormone use and incident endometrial cancer (n = 885) in 68,419 postmenopausal women with intact uteri enrolled in the National Institutes of Health-American Association of Retired Persons Diet and Health study. Participants completed a risk factor questionnaire in 1996-1997 and were followed up through 2006. Hazard rate ratios (RRs) and 95% confidence intervals (CIs) were estimated using Cox regression. Among 19,131 women reporting exclusive estrogen plus progestin use, 176 developed endometrial cancer (RR = 0.88; 95% CI = 0.74-1.06). Long-duration (≥ 10 years) sequential (<15 days progestin per month) estrogen plus progestin use was positively associated with risk (RR = 1.88; 95% CI = 1.36-2.60], whereas continuous (>25 days progestin per month) estrogen plus progestin use was associated with a decreased risk (RR = 0.64; 95% CI = 0.49-0.83). Increased risk for sequential estrogen plus progestin was seen only among thin-to-normal weight women (BMI < 25 kg/m(2); RR = 2.53). Our findings support that specific categories of estrogen plus progestin use increases endometrial cancer risk, specifically long durations of sequential progestins, whereas decreased endometrial cancer risk was observed for users of short-duration continuous progestins. Risks were highest among thin-to-normal weight women, presumably reflecting their lower endogenous estrogen levels, suggesting that menopausal hormones and obesity increase endometrial cancer through common etiologic pathways.

Breast cancer susceptibility polymorphisms and endometrial cancer risk: a Collaborative Endometrial Cancer Study

Recent large--scale association studies, both of genome-wide and candidate gene design, have revealed several single-nucleotide polymorphisms (SNPs) which are significantly associated with risk of developing breast cancer. As both breast and endometrial cancers are considered to be hormonally driven and share multiple risk factors, we investigated whether breast cancer risk alleles are also associated with endometrial cancer risk. We genotyped nine breast cancer risk SNPs in up to 4188 endometrial cases and 11,928 controls, from between three and seven Caucasian populations. None of the tested SNPs showed significant evidence of association with risk of endometrial cancer.

Current concepts in the pathology and epigenetics of endometrial carcinoma

In the Western world, endometrial carcinoma is the most common malignant tumour of the female genital tract and is the fourth most common cancer in women. Two different clinicopathological subtypes are recognised: the oestrogen-related (type I, endometrioid) and the non-oestrogen related (type II, non-endometrioid). This article reviews the epidemiology, risk factors, genetic alterations during endometrial carcinogenesis, features of tumours and precursors and early detection of the disease. Insights into the epigenetic alterations, with emphasis on DNA methylation during endometrial carcinogenesis, and their diagnostic value are also provided.

Menopausal hormone therapy and risk of endometrial carcinoma among postmenopausal women in the European Prospective Investigation Into Cancer and Nutrition

Estrogen-only menopausal hormone therapy (HT) increases the risk of endometrial cancer, but less is known about the association with other types of HT. Using Cox proportional hazards regression, the authors examined the association of various types of HT with the risk of endometrial cancer among 115,474 postmenopausal women recruited into the European Prospective Investigation into Cancer and Nutrition between 1992 and 2000. After a mean follow-up period of 9 years, 601 incident cases of endometrial cancer were identified. In comparison with never users of HT, risk of endometrial cancer was increased among current users of estrogen-only HT (hazard ratio (HR) = 2.52, 95% confidence interval (CI): 1.77, 3.57), tibolone (HR = 2.96, 95% CI: 1.67, 5.26), and, to a lesser extent, estrogen-plus-progestin HT (HR = 1.41, 95% CI: 1.08, 1.83), although risks differed according to regimen and type of progestin constituent. The association of HT use with risk was stronger among women who were older, leaner, or had ever smoked cigarettes. The finding of a strong increased risk of endometrial cancer with estrogen-only HT and a weaker association with combined HT supports the hypothesis that progestins have an attenuating effect on endometrial cancer risk. The increased risk associated with tibolone use requires further investigation.

Progesterone receptor gene variants and risk of endometrial cancer

Prolonged excessive estrogen exposure unopposed by progesterone is widely accepted to be a risk factor for endometrial cancer development. The physiological function of progesterone is dependent upon the presence of its receptor [progesterone receptor (PGR)] and several studies have reported single nucleotide polymorphisms (SNPs) in the PGR gene to be associated with endometrial cancer risk. We sought to confirm the associations with endometrial cancer risk previously reported for four different PGR polymorphisms. A maximum of 2888 endometrial cancer cases and 4483 female control subjects from up to three studies were genotyped for four PGR polymorphisms (rs1042838, rs10895068, rs11224561 and rs471767). Logistic regression with adjustment for age, study, ethnicity and body mass index was performed to calculate odds ratios (ORs) and associated 95% confidence intervals (CIs) and P-values. Of the four SNPs investigated, only rs11224561 in the 3' region of the PGR gene was found to be significantly associated with endometrial cancer risk. The A allele of the rs11224561 SNP was associated with increased risk of endometrial cancer (OR per allele 1.31; 95% CI 1.12-1.53, P = 0.001, adjusted for age and study), an effect of the same magnitude and direction as reported previously. We have validated the endometrial cancer risk association with a tagSNP in the 3' untranslated region of PGR previously reported in an Asian population. Replication studies will be required to refine the risk estimate and to establish if this, or a correlated SNP, is the underlying causative variant.

Hormone use and lung cancer incidence: the Rancho Bernardo cohort study

OBJECTIVE

This study examines the association of hormone use and lung cancer among women.

METHODS

This is a prospective study of 2,861 women aged 31 to 79 years from the Rancho Bernardo cohort. After enrollment in 1972 to 1974, women were followed up for 31 years for morbidity and mortality. Incident lung cancer was based on self-report or death certificates. Diagnosis was validated from the California Cancer Registry for cases that occurred after 1988. Cox proportional hazard models were used to estimate the adjusted association of hormone use and lung cancer.

RESULTS

During the 31-year follow-up, 87 women developed lung cancer. There was no association between hormone use and lung cancer (hazard ratio, 1.13; 95% CI, 0.73-1.73). Stratification by age 55 years (proxy for menopause status) showed divergent results. In women 55 years and older, lung cancer risk was 1.58 (95% CI, 0.95-2.53), whereas in women younger than 55 years, lung cancer risk was 0.44 (95% CI, 0.16-1.23). The confidence intervals for both groups contained the null value.

CONCLUSIONS

Although not statistically significant, our results from a long follow-up suggest that postmenopausal women on hormone therapy may have an increased risk of lung cancer, whereas younger women do not.

Reproductive factors and postmenopausal hormone use in relation to endometrial cancer risk in the Nurses' Health Study cohort 1976-2004

Endometrial cancer is a disease primarily driven by cumulative exposure to estrogen unopposed by progesterone. Reproductive factors associated with changes in endogenous hormone levels and use of exogenous hormones such as postmenopausal hormones influence the risk of disease. The authors used the Nurses' Health Study, comprised of 121,700 nurses, to assess the above associations. Over 28 years of follow-up, 778 adenocarcinoma cases were diagnosed and 1,850,078 person-years were accumulated. Cox proportional hazards models were used to estimate relative risks (RR) and 95% confidence intervals (CI). A late age at menarche decreased the risk independent of body mass index (BMI) (P-trend = 0.02). A late age at menopause increased cancer risk (P-trend = 0.0003). An advanced age at last birth reduced the risk (P-trend < 0.0001), however, an inverse association with age at first birth and parity diminished after adjustment for age at last birth. Compared with never users, an increased risk was observed among long-term (> or =5 years) users of both estrogen (E) (RR = 7.67, 95% CI: 5.57, 10.57) and combined estrogen plus progesterone (E+P) (RR = 1.52, 95% CI: 1.03, 2.23). Normal-weight (BMI < 25) women had the highest risk following E or E+P use (P-interaction-E = 0.0008, P-interaction-E+P = 0.02). The findings from this study underscore the importance of hormonal mechanisms in endometrial carcinogenesis.

Racial and ethnic variations in the incidence of cancers of the uterine corpus, United States, 2001-2003

OBJECTIVE

We examined racial/ethnic variations in uterine corpus cancer incidence.

METHODS

Data are from state cancer registries meeting quality criteria in the National Program of Cancer Registries (NPCR) and Surveillance, Epidemiology, and End Results (SEER) programs, 2001-2003. We included females with microscopically confirmed invasive uterine corpus cancer (n = 97,098). We calculated age-adjusted incidence rates per 100,000, stratified by race and ethnicity.

RESULTS

Cancers were most common among women who were 50-64 years old, white and non-Hispanic. Epithelial cancer rates were lower for Asian/Pacific Islanders (API) than whites (12.8 vs. 21.7, p < 0.0001), including serous adenocarcinoma (0.5 vs. 0.9, p < 0.0001). Epithelial cancer rates were also lower for American Indian/Alaska Natives (AIAN) vs. whites (11.5 vs. 21.7, p < 0.0001) and Hispanics vs. non-Hispanics (16.0 vs. 21.3, p < 0.0001). Among all race groups, blacks had the highest rates of mesenchymal (0.9) and mixed cancers (2.0) and of serous adenocarcinoma (2.0), clear cell adenocarcinoma (0.5), and carcinosarcoma (1.9). Blacks also had the lowest rates of low-grade and localized stage epithelial cancer and the highest rates of high-grade and distant stage disease.

CONCLUSIONS

Uterine corpus cancer rates are generally lower for API and AIAN than for whites or blacks and for Hispanics vs. non-Hispanics. Further research is needed to understand reasons for the differences in incidence.

Clique-finding for heterogeneity and multidimensionality in biomarker epidemiology research: the CHAMBER algorithm

BACKGROUND

Commonly-occurring disease etiology may involve complex combinations of genes and exposures resulting in etiologic heterogeneity. We present a computational algorithm that employs clique-finding for heterogeneity and multidimensionality in biomedical and epidemiological research (the "CHAMBER" algorithm).

METHODOLOGY/PRINCIPAL FINDINGS

This algorithm uses graph-building to (1) identify genetic variants that influence disease risk and (2) predict individuals at risk for disease based on inherited genotype. We use a set-covering algorithm to identify optimal cliques and a Boolean function that identifies etiologically heterogeneous groups of individuals. We evaluated this approach using simulated case-control genotype-disease associations involving two- and four-gene patterns. The CHAMBER algorithm correctly identified these simulated etiologies. We also used two population-based case-control studies of breast and endometrial cancer in African American and Caucasian women considering data on genotypes involved in steroid hormone metabolism. We identified novel patterns in both cancer sites that involved genes that sulfate or glucuronidate estrogens or catecholestrogens. These associations were consistent with the hypothesized biological functions of these genes. We also identified cliques representing the joint effect of multiple candidate genes in all groups, suggesting the existence of biologically plausible combinations of hormone metabolism genes in both breast and endometrial cancer in both races.

CONCLUSIONS

The CHAMBER algorithm may have utility in exploring the multifactorial etiology and etiologic heterogeneity in complex disease.

Progestogen deficiency and endometrial cancer risk

There is a close relationship between the amount of estogen and progesterone secreted by the ovary from puberty to menopause and the development of hyperplastic endometrium of all types and finally endometrial cancer. The endogenous endocrine pattern reflects progesterone deficiency (corpus luteum deficiency). Such deficiency can also develop when treatment with exogenous estrogen and progestogen is done and a deficiency of the progestogen in comparison to the used estrogen is induced in pre- and postmenopausal women. This risk is particular accentuated in the climacteric female when the endocrine milieu was unfavorable in the years before (menstrual cycle disorders, PCOS, obesity, no full-term pregnancy, no breast feeding, etc.). However, there are the additional factors, which modify the biological end result: "Progestogen deficiency". One main factor is the level of SHBG determined by the amount of free, biologically active estradiol. A low level of SHBG is for instance induced by high body weight. Therefore, the amount of overweight correlates with increased risk of endometrial hyperplasia and finally endometrial cancer. In addition, increasing body weight negatively affects proper ovarian function leading to corpus luteum deficiency and this in addition increases the risk of endometrial cancer. The classical risk increase for endometrial cancer is associated with oligomenorrhea or polymenorrhea combined with corpus luteum deficiency or anovulation. Therefore, women with PCOS are at increased risk for endometrial cancer in the pre- and postmenopausal years. Examples from the therapeutic point of view have been the risk increase found with biphasic estrogen high-dosed oral contraceptives with a long estrogen phase and a short progestogen phase. In climacteric females estrogen-only treatment results in a predictable increase in endometrial cancer risk. Therefore, it is mandatory to use estrogen/progestogen combinations. The lowest risk is achieved when a continuous estrogen/progestogen regimen is used. In addition, the lowest dose of estrogens for the individual woman should be chosen.

Hormone-dependent effects of FGFR2 and MAP3K1 in breast cancer susceptibility in a population-based sample of post-menopausal African-American and European-American women

FGFR2 and MAP3K1 are members of the RAS/RAF/MEK/ERK-signaling pathway and have been identified from genome-wide association studies to be breast cancer susceptibility genes. Potential interactions of these genes and their role with respect to tumor markers, hormonal factors and race on breast cancer risk have not been explored. We examined FGFR2 and MAP3K1 variants, breast tumor characteristics and hormone exposures in a population-based case-control sample of 1225 European-American (EA) and 584 African-American (AA) women. FGFR2 rs1219648 and rs2981582 genotypes were significantly associated with breast cancer in EA only in estrogen receptor-positive (ER+), progesterone receptor-positive (PR+) and HER2/Neu-negative (HER2-) tumors. MAP3K1 was not associated with breast cancer in EA women, but it was associated with breast cancer in AA women, again limited to ER+, PR+ and HER2- tumors. An interaction was observed between combined hormone replacement therapy use and FGFR2 rs1219648 genotypes on breast cancer risk in EA women (P = 0.010). Finally, we observed a significant interaction between MAP3K1 rs889312 and FGFR2 rs2981582 (P = 0.022) in AA but not EA women. These results confirm that FGFR2 and MAP3K1 are involved in breast cancer susceptibility and confer their effects primarily in ER+ and PR+ tumors. We further report that these genes confer their effects in HER2- tumors, interact with one another to confer breast cancer susceptibility in AA women and interact with hormone exposures in AA and EA women.