Specific binding and growth-promoting activity of insulin in endometrial cancer cells in culture

Endometrial Cancer in Reproductive-Aged Females: Etiology and Pathogenesis

Endometrial cancer is the most common gynecologic malignancy in developed countries, and the incidence is rising in premenopausal females. Type I EC is more common than Type II EC (80% vs. 20%) and is associated with a hyperestrogenic state. Estrogen unopposed by progesterone is considered to be the main driving factor in the pathogenesis of EC. Studies show that BMI > 30 kg/m2, prolonged duration of menses, nulliparity, presence of polycystic ovarian syndrome, and Lynch syndrome are the most common causes of EC in premenopausal women. Currently, there are no guidelines established to indicate premenopausal patients who should be screened. This review aims to synthesize current data on the etiology, risk factors, presentation, evaluation, and prognosis of endometrial cancer in this population.

Trend changes and factor analysis of endometrial hyperplasia in patients with polycystic ovarian syndrome based on the Korean National Health Insurance Database

Background

Polycystic ovary syndrome (PCOS) is a common endocrine disorder associated with an increased risk of other gynecological disorders, such as endometrial hyperplasia (EH). However, substantial factors in the comorbidity of EH and PCOS remain to be investigated. We analyzed trend changes in PCOS and factors related to the comorbidity of PCOS and EH using data from the Korea National Health Insurance (KNHI) claims database.

Methods

The data for this population-based study of people diagnosed with PCOS or EH in Korea from 2009 to 2016 were collected from the KNHI claims database between 2007 and 2017. We conducted a trend analysis of the prevalence and incidence of PCOS and EH. In addition, we performed a logistic regression analysis to identify risk factors associated with EH incidence in people with PCOS using the matched case-control methodology.

Results

The average annual growth rate of the incidence of PCOS was 14.1% from 2009 to 2016, whereas the EH rate increased by only 3.4% annually. Comorbidities, type 2 diabetes, obesity, hypertension, hyperlipidemia, and infertility, increased the risk of EH in PCOS patients. Additionally, the cumulative duration of oral contraceptive & progestin treatment for PCOS correlated highly with the comorbidity of EH and PCOS.

Conclusions

We confirmed the relationship between PCOS and EH using big data suitable for time series analyses of the diagnosis and treatment of diseases. Endometrial evaluation should be done with more caution if oral contraceptives & progestins have been used for a long time.

Metabolically Defined Body Size Phenotypes and Risk of Endometrial Cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC)

BACKGROUND

Obesity is a risk factor for endometrial cancer but whether metabolic dysfunction is associated with endometrial cancer independent of body size is not known.

METHODS

The association of metabolically defined body size phenotypes with endometrial cancer risk was investigated in a nested case-control study (817 cases/ 817 controls) within the European Prospective Investigation into Cancer and Nutrition (EPIC). Concentrations of C-peptide were used to define metabolically healthy (MH; <1st tertile) and metabolically unhealthy (MU; ≥1st tertile) status among the control participants. These metabolic health definitions were combined with normal weight (NW); body mass index (BMI)<25 kg/m2 or waist circumference (WC)<80 cm or waist-to-hip ratio (WHR)<0.8) and overweight (OW; BMI≥25 kg/m2 or WC≥80 cm or WHR≥0.8) status, generating four phenotype groups for each anthropometric measure: (i) MH/NW, (ii) MH/OW, (iii) MU/NW, and (iv) MU/OW.

RESULTS

In a multivariable-adjusted conditional logistic regression model, compared with MH/NW individuals, endometrial cancer risk was higher among those classified as MU/NW [ORWC, 1.48; 95% confidence interval (CI), 1.05-2.10 and ORWHR, 1.68; 95% CI, 1.21-2.35] and MU/OW (ORBMI, 2.38; 95% CI, 1.73-3.27; ORWC, 2.69; 95% CI, 1.92-3.77 and ORWHR, 1.83; 95% CI, 1.32-2.54). MH/OW individuals were also at increased endometrial cancer risk compared with MH/NW individuals (ORWC, 1.94; 95% CI, 1.24-3.04).

CONCLUSIONS

Women with metabolic dysfunction appear to have higher risk of endometrial cancer regardless of their body size. However, OW status raises endometrial cancer risk even among women with lower insulin levels, suggesting that obesity-related pathways are relevant for the development of this cancer beyond insulin.

IMPACT

Classifying women by metabolic health may be of greater utility in identifying those at higher risk for endometrial cancer than anthropometry per se.

Survival outcomes in endometrial cancer patients according to diabetes: a systematic review and meta-analysis

BACKGROUND

Diabetes is an established risk factor for endometrial cancer development but its impact on prognosis is unclear and epidemiological studies to date have produced inconsistent results. We aimed to conduct the first systematic review and meta-analysis to compare survival outcomes in endometrial cancer patients with and without pre-existing diabetes.

METHODS

We conducted a systematic search of MEDLINE, EMBASE and Web of Science databases up to February 2022 for observational studies that investigated the association between pre-existing diabetes and cancer-specific survival in endometrial cancer patients. Secondary outcomes included overall survival and progression or recurrence-free survival. Quality assessment of included studies was undertaken using the Newcastle-Ottawa Scale and a random-effects model was used to produce pooled hazard ratios (HRs) and 95% confidence intervals (CIs). (PROSPERO 2020 CRD42020196088).

RESULTS

In total, 31 studies were identified comprising 55,475 endometrial cancer patients. Pooled results suggested a worse cancer-specific survival in patients with compared to patients without diabetes (n = 17 studies, HR 1.15, 95% CI 1.00-1.32, I2 = 62%). Similar results were observed for progression or recurrence-free survival (n = 6 studies, HR 1.23, 95% CI 1.02-1.47, I2 = 0%) and for overall survival (n = 24 studies, HR 1.42, 95% CI 1.31-1.54, I2 = 46%).

CONCLUSION

In this systematic review and meta-analysis, we show that diabetes is associated with a worse cancer-specific and overall survival in endometrial cancer patients.

A molecular link between diabetes and breast cancer: Therapeutic potential of repurposing incretin-based therapies for breast cancer

Female breast cancer recently surpassed lung cancer and became the most commonly diagnosed cancer worldwide. As per the recent data from WHO, breast cancer accounts for one out of every 8 cancer cases diagnosed among an estimated 2.3 million new cancer cases. Breast cancer is the most prevailing cancer type among women causing the highest number of cancer-related mortality. It has been estimated that in 2020, 68,5000 women died due to this disease. Breast cancers have varying degrees of molecular heterogeneity; therefore, they are divided into various molecular clinical sub types. Recent reports suggest that type 2 diabetes (one of the common chronic diseases worldwide) is linked to the higher incidence, accelerated progression, and aggressiveness of different cancers; especially breast cancer. Breast cancer is hormone-dependent in nature and has a cross-talk with metabolism. A number of antidiabetic therapies are known to exert beneficial effects on various types of cancers, including breast cancer. However, only a few reports are available on the role of incretin-based antidiabetic therapies in cancer as a whole and in breast cancer in particular. The present review sheds light on the potential of incretin based therapies on breast cancer and explores the plausible underlying mechanisms. Additionally, we have also discussed the sub types of breast cancer as well as the intricate relationship between diabetes and breast cancer.

Statistical Meta-Analysis of Risk Factors for Endometrial Cancer and Development of a Risk Prediction Model Using an Artificial Neural Network Algorithm

Simple Summary

A robust and comprehensive meta-analysis, for the first time, identified definitely that BMI is by far the most influential risk factor in endometrial cancer. Risk factors were previously only studied individually and or in smaller meta-analysis studies which grouped some factors together. BMI was shown to be an important risk factor with other factors less so, but no rank order was established. This work also offers, for the first time, a neural network computer model to predict the overall increase or decreased risk of cancer for individual patients, which is 98.6% accurate. This prediction can be used as a tool to determine if a patient should be considered for testing and to predict diagnosis, as well as to suggest prevention measures to patients.

Abstract

Objectives: In this study we wished to determine the rank order of risk factors for endometrial cancer and calculate a pooled risk and percentage risk for each factor using a statistical meta-analysis approach. The next step was to design a neural network computer model to predict the overall increase or decreased risk of cancer for individual patients. This would help to determine whether this prediction could be used as a tool to decide if a patient should be considered for testing and to predict diagnosis, as well as to suggest prevention measures to patients. Design: A meta-analysis of existing data was carried out to calculate relative risk, followed by design and implementation of a risk prediction computational model based on a neural network algorithm. Setting: Meta-analysis data were collated from various settings from around the world. Primary data to test the model were collected from a hospital clinic setting. Participants: Data from 40 patients notes currently suspected of having endometrial cancer and undergoing investigations and treatment were collected to test the software with their cancer diagnosis not revealed to the software developers. Main outcome measures: The forest plots allowed an overall relative risk and percentage risk to be calculated from all the risk data gathered from the studies. A neural network computational model to determine percentage risk for individual patients was developed, implemented, and evaluated. Results: The results show that the greatest percentage increased risk was due to BMI being above 25, with the risk increasing as BMI increases. A BMI of 25 or over gave an increased risk of 2.01%, a BMI of 30 or over gave an increase of 5.24%, and a BMI of 40 or over led to an increase of 6.9%. PCOS was the second highest increased risk at 4.2%. Diabetes, which is incidentally also linked to an increased BMI, gave a significant increased risk along with null parity and noncontinuous HRT of 1.54%, 1.2%, and 0.56% respectively. Decreased risk due to contraception was greatest with IUD (intrauterine device) and IUPD (intrauterine progesterone device) at −1.34% compared to −0.9% with oral. Continuous HRT at −0.75% and parity at −0.9% also decreased the risk. Using open-source patient data to test our computational model to determine risk, our results showed that the model is 98.6% accurate with an algorithm sensitivity 75% on average. Conclusions: In this study, we successfully determined the rank order of risk factors for endometrial cancer and calculated a pooled risk and risk percentage for each factor using a statistical meta-analysis approach. Then, using a computer neural network model system, we were able to model the overall increase or decreased risk of cancer and predict the cancer diagnosis for particular patients to an accuracy of over 98%. The neural network model developed in this study was shown to be a potentially useful tool in determining the percentage risk and predicting the possibility of a given patient developing endometrial cancer. As such, it could be a useful tool for clinicians to use in conjunction with other biomarkers in determining which patients warrant further preventative interventions to avert progressing to endometrial cancer. This result would allow for a reduction in the number of unnecessary invasive tests on patients. The model may also be used to suggest interventions to decrease the risk for a particular patient. The sensitivity of the model limits it at this stage due to the small percentage of positive cases in the datasets; however, since this model utilizes a neural network machine learning algorithm, it can be further improved by providing the system with more and larger datasets to allow further refinement of the neural network.

Uterine anomalies in cell proliferation, energy homeostasis and oxidative stress in PCOS hamsters, M. auratus: Therapeutic potentials of melatonin

AIMS

Polycystic ovarian syndrome (PCOS) is a reproductive, endocrine and metabolic disorder. Less is known about the mechanism of its effect on uterine function and therapeutic potential of melatonin. Our aim was to evaluate uterine dysfunction(s) in letrozole induced PCOS and its possible rectification by melatonin.

MAIN METHODS

Adult female golden hamsters were divided into groups of Control (C), Melatonin (M; 1 mg/kg b.w.), Letrozole (L; 3 mg/kg b.w.) and combination of Letrozole+Melatonin (L + M; 3 mg/kg b.w. + 1 mg/kg b.w.) which were treated for 40 days. Analysis of serum testosterone/estradiol/progesterone/leptin/insulin, uterine histomorphometry, immunohistochemistry for proliferation cell nuclear antigen (PCNA), homeostatic assessment model of insulin resistance (HOMA-IR), western blotting for PCNA, androgen receptor (AR), insulin receptor (InsR), glucose tansporter-4 (GLUT-4), nuclear factor-kappa B (NFκB), cyclooxygenase-2 (COX-2) and biochemical analysis of superoxide dismutase (SOD)/catalase/lipid peroxidation (LPO) were done.

KEY FINDINGS

Serum testosterone, leptin and insulin increased while uterine InsR/GLUT-4 expression decreased in L group indicating metabolic abnormalities. Endometrial hyperplasia, increased expression of PCNA and AR indicated abnormal proliferation in L compared to C. Increased uterine oxidative load (SOD/catalase/LPO) and inflammatory markers NFκB/COX-2 expression in L was responsible for high tissue oxidative stress and inflammation. M administration normalized all the above parameters suggesting its ameliorative effect in L + M group.

SIGNIFICANCE

We report PCOS induced uterine dysfunction in Mesocricetus auratus for the first time. M administration restores uterine functions modulating cellular dynamicity, metabolic status, decreased oxidative and inflammatory load in PCOS hamsters. Therefore, we suggest the therapeutic potential of M against PCOS led uterine abnormalities to restore female fertility.

Does Nutrition Affect Endometriosis?

Endometriosis is a hormone-related, chronic inflammation in women of childbearing age. The aetiology and pathogenesis of endometriosis are not yet fully understood. For other illnesses classed as lifestyle diseases, the link between nutrition and pathogenesis has already been researched and proven. With regard to these findings, the question continues to arise as to whether and how a specific diet and lifestyle could also influence pathogenesis and the progression of endometriosis. The aim of this review is to examine the data and determine what influence nutrition has on the development of endometriosis or on existing disease. The study results currently available do not permit a clear, scientific recommendation or indicate a detailed diet. In summary, it can be said that fish oil capsules in combination with vitamin B ₁₂ have been associated with a positive effect on endometriosis symptoms (particularly of dysmenorrhoea). Alcohol and increased consumption of red meat and trans fats are associated with a negative effect. The results of the studies listed with regard to fruit and vegetables, dairy products, unsaturated fats, fibre, soy products and coffee are not clear. Therefore, the general recommendations for a balanced and varied diet in line with the guidelines of the Deutsche Gesellschaft für Ernährung e. V. [German Nutrition Society] apply, along with the recommendation to cut out alcohol. In order to be able to derive more concrete recommendations, we require further studies to investigate the influence of nutrition on endometriosis.

Differential Expressions of Ki-67, Bcl-2, and Apoptosis Index in Endometrial Cells of Women With and Without Type II Diabetes Mellitus and Their Correlation with Clinicopathological Variables

The objective of this study was to investigate proliferation, apoptosis, and antiapoptotic molecule expression in endometrial cells of reproductive-aged women with and without type II diabetes mellitus (T2D). In this case-control study, a total of 80 endometrial tissue specimens from reproductive-aged women (35 in the proliferative phase and 45 in the secretory phase) were examined. The age and body mass index (BMI) were matched between the groups. Formalin-fixed and paraffin-embedded endometrial tissue samples were used for immunohistochemistry analysis. The presence of proliferation was evaluated with Ki-67 expression, antiapoptotic function of cells was evaluated with Bcl-2 expression, and apoptosis was evaluated with terminal deoxynucleotidyl transferase (TUNEL) immunoreactivity in both the glandular epithelium and stroma of endometrial tissue samples from women with and without T2D. Ki-67 expression in the glandular epithelium and Bcl-2 expression in both the glandular epithelium and stroma were significantly higher in endometrial tissue samples of women in the T2D group than the control group (p = 0.0008, p = 0.0022, and p = 0.0261, respectively). TUNEL immunoreactivity was significantly lower in the glandular epithelium of women in the T2D group than the control group (p = 0.0001). Glandular Ki-67 expression correlated positively with BMI, use of insulin, and hemoglobin A1c level (p = 0.0034, p = 0.0154, and p = 0.0011, respectively). Glandular Bcl-2 expression correlated positively with BMI and duration of T2D (p = 0.0090 and p = 0.0109, respectively). Stromal Bcl-2 expression correlated positively with duration of T2D (p = 0.0069). TUNEL immunoreactivity in the glandular epithelium correlated negatively with duration of T2D (p = 0.0340) and positively with the use of oral antidiabetic agents (p = 0.0226). Compared to age and BMI-matched controls, women with T2D experienced increased cell proliferation and decreased apoptosis in the glandular epithelium and increased antiapoptotic function in both the glandular epithelium and stromal cells. High BMI values in women with diabetes seemed to contribute to increased cell proliferation and increased antiapoptotic function in the glandular epithelium but not the stromal cells.

Interventions to improve insulin resistance for the prevention of endometrial cancer

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

To determine the safety and effectiveness of interventions to improve insulin resistance for the prevention of atypical endometrial hyperplasia or endometrial cancer, or both.

The Effects of the Dietary and Nutrient Intake on Gynecologic Cancers

The contribution of diet to cancer risk has been considered to be higher in advanced countries than in developing countries. In this paper, I review the current issues (a review of the relevant literature), and the effects of the dietary and nutrient intake on three types of gynecologic cancer (cervical, endometrial and ovarian cancers). In cervical cancer, the most important roles of diet/nutrition in relation to cancer are prophylaxis and countermeasures against human papillomavirus (HPV) infection. The main preventive and reductive factors of cervical cancer are antioxidants, such as vitamin A, C, D and E, carotenoids, vegetables and fruits. These antioxidants may have different abilities to intervene in the natural history of diseases associated with HPV infection. For endometrial cancer, the increase in peripheral estrogens as a result of the aromatization of androgens to estrogens in adipose tissue in obese women and insulin resistance are risk factors. Thus, we must mainly take care to avoid the continuous intake of fat energy and sugar. In ovarian cancer, the etiology has not been fully understood. To the best of our knowledge, the long-term consumption of pro-inflammatory foods, including saturated fat, carbohydrates and animal proteins is a risk factor. The intake of acrylamide is also a risk factor for both endometrial and ovarian cancer. Most papers have been epidemiological studies. Thus, further research using in vitro and in vivo approaches is needed to clarify the effects of the dietary and nutrient intake in detail.

The effect of diabetes on the risk of endometrial Cancer: an updated a systematic review and meta-analysis

BACKGROUND

Previous studies conducted on the association between diabetes and the risk of endometrial cancer have reported controversial results that have raised a variety of questions about the association between diabetes and the incidence of this cancer. Thus, the aim of this systematic review and meta-analysis was to more precisely estimate the effect of diabetes on the risk of endometrial cancer incidence.

METHODS

All original articles were searched in international databases, including Medline (PubMed), Web of sciences, Scopus, EMBASE, and CINHAL. Search was done from January 1990 to January 2018 without language limitations. Also, logarithm and standard error logarithm relative risk (RR) were used for meta-analysis.

RESULTS

A total of 22 cohort and case-control studies were included in this meta-analysis, of which 14 showed statistically significant associations between diabetes and risk of endometrial cancer. Diabetes was associated with increased risk of endometrial cancer (RR = 1.72, 95% CI 1.48-2.01). The summary of RR for all 9 cohort studies was 1.56 (95% CI 1.21-2.01), and it was 1.85 (95% CI 1.53-2.23) for 13 case control studies. The summary of RR in hospital-based studies was higher than other studies. Thirteen of the primary studies-controlled BMI as a confounding variable, and the combined risk of their results was 1.62 (95% CI 1.34-1.97).

CONCLUSIONS

Diabetes seems to increases the risk of endometrial cancer in women, and this finding can be useful in developing endometrial cancer prevention plans for women having diabetes.

Association of endometrial hyperplasia and cancer with a history of gestational diabetes

PURPOSE

Excess circulating insulin may contribute to endometrial cancer (EC) development; studies suggest increased risk of EC associated with type 2 diabetes. We investigated whether gestational diabetes is associated with increased risk of EC and its precursor, endometrial hyperplasia (EH).

METHODS

We conducted a population-based, case-control study of women in Washington State. Cases were women with a hospital discharge record indicating the presence of EH/EC who could be linked to a prior delivery hospitalization or birth record from 1987 to 2013 (n = 593). Controls were randomly selected from remaining deliveries, frequency matched 10:1 on delivery year and maternal age at delivery (n = 5,743). Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

After adjustment for race/ethnicity, maternal age at delivery, and delivery year, EH/EC was associated with a history of gestational diabetes (OR 1.73, 95% CI 1.27-2.35). This association was present for both EH and EC (OR 1.61, 95% CI 1.00-2.60 and OR 1.80, 95% CI 1.22-2.65, respectively). After adjustment for prepregnancy body mass index, the OR for EH/EC was attenuated and became statistically non-significant (OR 1.22, 95% CI 0.87-1.72), except in women <50 years old at the time of case ascertainment (OR 1.49, 95% CI 1.00-2.20). Associations were slightly stronger for EC than EH.

CONCLUSIONS

We observed an association between EH/EC and a history of gestational diabetes specific to younger women. Future studies focusing on the relationships between gestational diabetes, obesity, and EC, including age at diagnosis, are warranted.

Epidemiology of Endometrial Carcinoma: Etiologic Importance of Hormonal and Metabolic Influences

Endometrial carcinoma is the most common gynecologic cancer in developed nations, and the annual incidence is projected to increase, secondary to the high prevalence of obesity, a strong endometrial carcinoma risk factor. Although endometrial carcinomas are etiologically, biologically, and clinically diverse, hormonal and metabolic mechanisms are particularly strongly implicated in the pathogenesis of endometrioid carcinoma, the numerically predominant subtype. The centrality of hormonal and metabolic disturbances in the pathogenesis of endometrial carcinoma, combined with its slow development from well-characterized precursors in most cases, offers a substantial opportunity to reduce endometrial carcinoma mortality through early detection, lifestyle modification, and chemoprevention. In this chapter, we review the epidemiology of endometrial carcinoma, emphasizing theories that link risk factors for these tumors to hormonal and metabolic mechanisms. Future translational research opportunities related to prevention are discussed.

Up-regulation of genes involved in the insulin signalling pathway (IGF1, PTEN and IGFBP1) in the endometrium may link polycystic ovarian syndrome and endometrial cancer

BACKGROUND

Endometrial cancer (EC) is the most common gynaecological cancer amongst women in the UK. Although previous studies have found that women with polycystic ovary syndrome (PCOS) have at least a three-fold increase in endometrial cancer (EC) risk compared to women without PCOS, the precise molecular mechanisms which link between PCOS and EC remain unclear. It has been suggested that insulin resistance may contribute to the increased risk of EC in PCOS. The specific expression of genes related to the insulin-signalling pathway including the IGF system in the endometrium of women with PCOS has however never been measured and compared to that in women with EC without PCOS and control women without EC or PCOS. .

OBJECTIVES

To test the hypothesis that insulin signalling plays a key role in the development of EC in women with PCOS by measuring and comparing the expression of three key genes involved in the insulin signalling pathway (IGF1, PTEN and IGFBP1) in endometrial tissue obtained from three groups of women; PCOS without EC, women with EC without PCOS and non-PCOS women without EC (controls). We also aimed to determine the correlation between the gene expressions to various clinical variables among participants.

METHODS

This was a cross-sectional study of 102 women in 3 groups (PCOS, EC and controls) at a University teaching hospital in the United Kingdom. Clinical assessment (blood pressure, body mass index (BMI) and waist-hip-circumference ratio), venepuntures (fasting blood sugar, insulin, lipid profile, hormones) and endometrial tissue biopsies were taken in all participants. Endometrial tissue RNA extraction was performed before real time polymerase-chain-reaction for the genes of interest (IGF1, IGFBP1 and PTEN) was carried out. To compare the baseline characteristics of the study population, One-Way-ANOVA test or the Independent t-test was used. For variables that were not normally distributed, the Spearman correlation test was used to calculate the r value. A "p" value of <0.05 was considered statistically significant.

RESULTS

IGF1, IGFBP1 and PTEN gene expression were significantly up-regulated in the endometrium of PCOS and EC women compared to controls. However there was no significant difference in the expression of these genes in PCOS compared to EC endometrium. The BMI of women with PCOS and controls, were not significantly different (29.28 (± 2.91) vs 28.58 (± 2.62) kg/m(2)) respectively, women with EC however had a higher mean BMI (32.22 (± 5.70) kg/m(2)). PCOS women were younger (31.8 (± 5.97) years) than women with EC (63.44 (± 10.07) years) and controls (43.68 (± 13.12) years). The changes in gene expression were independent of BMI, waist hip ratio, estradiol and androgen levels. Protein validation test in the serum samples in the three groups were consistent with the gene findings.

CONCLUSION

Women with PCOS and EC have an increased endometrial expression of genes (IGF1, IGFBP1 and PTEN) involved in the insulin signalling pathway compared with control women. This may explain the increased risk of EC in PCOS women. This study provides a strong basis for clinical trials aiming to prevent EC in women with PCOS by investigating drugs targeting the insulin signalling pathway. This panel of genes may also serve as clinically useful early biomarkers which predict which women with PCOS will go on to develop EC.

Dietary insulin index and insulin load in relation to endometrial cancer risk in the Nurses' Health Study

BACKGROUND

Although unopposed estrogen exposure is considered the main driver of endometrial carcinogenesis, factors associated with states of insulin resistance and hyperinsulinemia are independently associated with endometrial cancer risk. We used dietary insulin load and insulin index scores to represent the estimated insulin demand of overall diets and assessed their association with endometrial cancer risk in the prospective Nurses' Health Study.

METHODS

We estimated incidence rate ratios (RR) and 95% confidence intervals (CI) for risk of invasive endometrial cancer using Cox proportional hazards models. Between the baseline dietary questionnaire (1980) and 2010, we identified a total of 798 incident-invasive epithelial endometrial adenocarcinomas over 1,417,167 person-years of follow-up.

RESULTS

Dietary insulin scores were not associated with overall risk of endometrial cancer. Comparing women in the highest with the lowest quintile, the multivariable-adjusted RRs of endometrial cancer were 1.07 (95% CI, 0.84-1.35) for cumulative average dietary insulin load and 1.03 (95% CI, 0.82-1.31) for cumulative average dietary insulin index. Findings did not vary substantially by alcohol consumption, total dietary fiber intake, or body mass index and/or physical activity (P(heterogeneity) ≥ 0.10).

CONCLUSIONS

Intake of a diet predicted to stimulate a high postprandial insulin response was not associated with endometrial cancer risk in this large prospective study. Considering the complex interplay of diet, lifestyle, and genetic factors contributing to the hyperinsulinemic state, dietary measures alone may not sufficiently capture absolute long-term insulin exposure.

IMPACT

This study is the first to investigate dietary insulin scores in relation to endometrial cancer risk.

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.

Insulin exerts direct effects on carcinogenic transformation of human endometrial organotypic cultures

Epidemiological studies suggest an association between elevated insulin levels and endometrial cancer. We studied the effects of insulin on normal endometrial cell proliferation with cytotoxicity assays. Organotypic cultures were used to determine the effects of insulin on the development of malignant histological features and anchorage independent growth. Western Blots were used to analyze the mitogen-activated protein kinases and AKT pathways. We found that insulin exerts direct effects on endometrial cells by increasing proliferation and promoting carcinogenesis. Our results suggest that this occurs through ERK 1/2 and glycogen synthase kinase-3β Ser9 phosphorylation.

High coffee consumption and different brewing methods in relation to postmenopausal endometrial cancer risk in the Norwegian women and cancer study: a population-based prospective study

Background

Coffee and its compounds have been proposed to inhibit endometrial carcinogenesis. Studies in the Norwegian population can be especially interesting due to the high coffee consumption and increasing incidence of endometrial cancer in the country.

Methods

A total of 97 926 postmenopausal Norwegian women from the population-based prospective Norwegian Women and Cancer (NOWAC) Study, were included in the present analysis. We evaluated the general association between total coffee consumption and endometrial cancer risk as well as the possible impact of brewing method. Multivariate Cox regression analysis was used to estimate risks, and heterogeneity tests were performed to compare brewing methods.

Results

During an average of 10.9 years of follow-up, 462 incident endometrial cancer cases were identified. After multivariate adjustment, significant risk reduction was found among participants who drank ≥8 cups/day of coffee with a hazard ratio of 0.52 (95% confidence interval, CI 0.34-0.79). However, we did not observe a significant dose-response relationship. No significant heterogeneity in risk was found when comparing filtered and boiled coffee brewing methods. A reduction in endometrial cancer risk was observed in subgroup analyses among participants who drank ≥8 cups/day and had a body mass index ≥25 kg/m², and in current smokers.

Conclusions

These data suggest that in this population with high coffee consumption, endometrial cancer risk decreases in women consuming ≥8 cups/day, independent of brewing method.

Combination of Diane-35 and Metformin to Treat Early Endometrial Carcinoma in PCOS Women with Insulin Resistance

Background: Young women with polycystic ovary syndrome (PCOS) have a high risk of developing endometrial carcinoma. There is a need for the development of new medical therapies that can reduce the need for surgical intervention so as to preserve the fertility of these patients. The aim of the study was to describe and discuss cases of PCOS and insulin resistance (IR) women with early endometrial carcinoma while being co-treated with Diane-35 and metformin.

Methods: Five PCOS-IR women who were scheduled for diagnosis and therapy for early endometrial carcinoma were recruited. The hospital records and endometrial pathology reports were reviewed. All patients were co-treated with Diane-35 and metformin for 6 months to reverse the endometrial carcinoma and preserve their fertility. Before, during, and after treatment, endometrial biopsies and blood samples were obtained and oral glucose tolerance tests were performed. Endometrial pathology was evaluated. Body weight (BW), body mass index (BMI), follicle-stimulating hormone (FSH), luteinizing hormone (LH), total testosterone (TT), sex hormone-binding globulin (SHBG), free androgen index (FAI), insulin area under curve (IAUC), and homeostasis model assessment of insulin resistance (HOMA-IR) were determined.

Results: Clinical stage 1a, low grade endometrial carcinoma was confirmed before treatment. After 6 months of co-treatment, all patients showed normal epithelia. No evidence of atypical hyperplasia or endometrial carcinoma was found. Co-treatment resulted in significant decreases in BW, BMI, TT, FAI, IAUC, and HOMA-IR in parallel with a significant increase in SHBG. There were no differences in the FSH and LH levels after co-treatment.

Conclusions: Combined treatment with Diane-35 and metformin has the potential to revert the endometrial carcinoma into normal endometrial cells in PCOS-IR women. The cellular and molecular mechanisms behind this effect merit further investigation.

Obesity is associated with higher 4E-BP1 expression in endometrial cancer

PURPOSE

Obesity is associated with risk and prognosis of endometrial cancer (EC), and the mammalian target of rapamycin complex 1 (mTORC1) pathway may play an instrumental role. We sought to explore the associations between cellular proliferation, Akt, and 4E binding protein-1 (4E-BP1) (a downstream target of mTORC1), in obese and nonobese women with and without EC.

METHODS

Archival tissue-specimens from endometrial biopsies were grouped into two broad categories based on the observed disease behavior and similarities in tissue staining patterns: benign/hyperplasia (without cytologic atypia) (n=18) versus atypia (complex hyperplasia with cytologic atypia)/carcinoma (n=25). The characteristics of the study population, including height and weight to determine body mass index (BMI: kg/m²), were abstracted from medical records. Immunohistochemistry was used to assess the phosphorylated (p)Akt, p4E-BP1, and antigen Ki67.

RESULTS

Cytoplasmic and nuclear pAkt were significantly associated with cytoplasmic p4E-BP1 (ρ=+0.48, ρ=+0.50) (P<0.05) and nuclear p4E-BP1 (ρ=+0.40, ρ=+0.44) (P<0.05); cytoplasmic and nuclear p4E-BP1 were significantly associated with Ki67 (ρ=+0.46, ρ=+0.59) (P<0.05). Compared with the benign/hyperplasia group, the women with atypia/carcinoma had significantly higher cytoplasmic and nuclear p4E-BP1 and Ki67. This staining pattern was similar in obese women; however, in nonobese women, neither cytoplasmic nor nuclear p4E-BP1staining differed between benign/hyperplasia versus atypia/carcinoma.

CONCLUSION

The activation of 4E-BP1 was higher in the obese women with EC. Adiposity may be a key factor to consider in future studies investigating the role of 4E-BP1 as a biomarker and therapeutic target in EC.

Evaluating vaspin and adiponectin in postmenopausal women with endometrial cancer

Insulin resistance is a well-documented risk factor for the development of endometrial cancer. Adiponectin and vaspin are insulin-sensitizing proteins that are secreted from adipose tissue. A clear association between serum levels of adipokines and endometrial cancer has yet to be established. The study group consisted of postmenopausal women with confirmed endometrial cancer, whereas patients with benign endometrial conditions constituted the control group. The two groups were compared in terms of insulin resistance and serum levels of adiponectin and vaspin. A total of 60 patients with confirmed endometrial cancer and 70 controls with benign endometrial conditions (polyps and atrophy) were enrolled. Median homeostasis model assessment of insulin resistance value was significantly higher in the study group compared with the control group (2.93 vs 1.27, P<0.0001), whereas mean quantitative insulin sensitivity check index value was significantly lower (0.33 ± 0.02 vs 0.37 ± 0.37, P<0.0001). Median values for both adiponectin and vaspin were significantly lower in patients with endometrial cancer compared with the control group (4.09 vs 17.13 μg/ml, P<0.0001 and 0.21 vs 0.39 ng/ml, P<0.0001 respectively). Low levels of both adiponectin and vaspin were found to be significantly associated with an increased risk for endometrial cancer. Following adjustment for confounding factors, the respective odds ratios for endometrial cancer in patients in the first tertile compared with those in the third tertile were 10.80 (2.76-42.24; P=0.001) and 13.23 (2.94-59.64; P=0.001). Our results show that lower levels of circulating adiponectin and vaspin levels are associated with an increased risk of developing endometrial cancer.

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.

Prevalence of diagnosed cancer according to duration of diagnosed diabetes and current insulin use among U.S. adults with diagnosed diabetes: findings from the 2009 Behavioral Risk Factor Surveillance System

OBJECTIVE

To estimate the prevalence of diagnosed cancer according to duration of diagnosed diabetes and current insulin use among U.S. adults with diagnosed diabetes.

RESEARCH DESIGN AND METHODS

We analyzed data from 25,964 adults aged ≥ 18 years with diagnosed diabetes who participated in the 2009 Behavioral Risk Factor Surveillance System.

RESULTS

After adjustment for potential confounders, we found that the greater the duration of diagnosed diabetes, the higher the prevalence of diagnosed cancers (P < 0.0001 for linear trend). Among adults with diagnosed type 2 diabetes, the prevalence estimate for cancers of all sites was significantly higher among men (adjusted prevalence ratio 1.6 [95% CI 1.3-1.9]) and women (1.8 [1.5-2.1]) who reported being diagnosed with diabetes ≥ 15 years ago than among those reporting diabetes diagnosis <15 years ago. The prevalence estimate for cancers of all sites was ~1.3 times higher among type 2 diabetic adults who currently used insulin than among those who did not use insulin among both men (1.3 [1.1-1.6]) and women (1.3 [1.1-1.5]).

CONCLUSIONS

Our results suggest that there is an increased burden of diagnosed cancer among adults with a longer duration of diagnosed diabetes and among type 2 diabetic adults who currently use insulin.

Life-style and metformin for the prevention of endometrial pathology in postmenopausal women

In western women, the endometrium is frequently exposed, even after menopause, to the endogenous hormonal stimulation. Such a stimulation increases the risk of pathologic conditions such as endometrial hyperplasia and type I (endometrioid) endometrial adenocarcinoma. Metabolic syndrome, obesity, insulin resistance and type II diabetes promote the endometrial stimulation, and are recognized risk factors for endometrial cancer. Furthermore, chronic hyperinsulinemia linked both to obesity and metabolic syndrome influences endometrial proliferation through direct and indirect actions. Intentional weight loss, calorie restriction and physical activity are associated with a reduced risk of the endometrial pathology. Biological mechanisms include reduction in insulin and sex steroid hormone levels. In addition to life-style modifications, the antidiabetic metformin may be proposed as preventive agent. Metformin reduces the metabolic syndrome, lowers insulin and testosterone levels in postmenopausal women, and it is a potent inhibitor of endometrial cancer cell proliferation.

Insulin resistance and cancer: the role of insulin and IGFs

Insulin, IGF1, and IGF2 are the most studied insulin-like peptides (ILPs). These are evolutionary conserved factors well known as key regulators of energy metabolism and growth, with crucial roles in insulin resistance-related metabolic disorders such as obesity, diseases like type 2 diabetes mellitus, as well as associated immune deregulations. A growing body of evidence suggests that insulin and IGF1 receptors mediate their effects on regulating cell proliferation, differentiation, apoptosis, glucose transport, and energy metabolism by signaling downstream through insulin receptor substrate molecules and thus play a pivotal role in cell fate determination. Despite the emerging evidence from epidemiological studies on the possible relationship between insulin resistance and cancer, our understanding on the cellular and molecular mechanisms that might account for this relationship remains incompletely understood. The involvement of IGFs in carcinogenesis is attributed to their role in linking high energy intake, increased cell proliferation, and suppression of apoptosis to cancer risks, which has been proposed as the key mechanism bridging insulin resistance and cancer. The present review summarizes and discusses evidence highlighting recent advances in our understanding on the role of ILPs as the link between insulin resistance and cancer and between immune deregulation and cancer in obesity, as well as those areas where there remains a paucity of data. It is anticipated that issues discussed in this paper will also recover new therapeutic targets that can assist in diagnostic screening and novel approaches to controlling tumor development.

Targeting IGF-1 signaling pathways in gynecologic malignancies

INTRODUCTION

The signaling pathways of the insulin-like growth factors (IGF) have been implicated in the etiology of a number of epithelial neoplasms including prostate, breast, colon and more recently, gynecologic cancers. The insulin-like growth factor-1 receptor (IGF-1R) is expressed in most transformed cells, where it displays potent anti-apoptotic, cell-survival and potentially, transforming activities. IGF-1R expression and activation are typical hallmarks associated with tumor initiation and progression. Multiple approaches have been used to abrogate IGF-1R signaling for targeted cancer therapy including antibodies and small molecule tyrosine kinase inhibitors. These novel IGF-1R targeting agents have produced significant experimental and clinical results in many cancers and generated considerable optimism in the field of cancer therapy.

AREAS COVERED

The authors will review important research advances regarding the role of the IGF axis in cancer, particularly preclinical and clinical studies in cervical, uterine and ovarian cancers. The significance of tumor expression and circulating levels of the IGF pathway as well as targeting therapies of the IGF axis in the gynecologic cancers will be discussed.

EXPERT OPINION

Accumulating data confirm that the IGF-1R pathway has an important role in gynecologic cancers and in vivo and in vitro studies have shown a significant impact of IGF-1R targeted therapies in these malignancies, mainly ovarian and endometrial cancers. Currently, ongoing preclinical and clinical trials are evaluating the efficacy of IGF-1R targeting. A better understanding of the complex mechanisms underlying the regulation of the IGF system will improve the ability to develop effective treatment modalities for these malignancies.

Case-control study of markers of insulin resistance and endometrial cancer risk

Markers of insulin resistance such as the adiponectin:leptin ratio (A:L) and the homeostasis model assessment ratio (HOMA-IR) are associated with obesity and hyperinsulinemia, both established risk factors for endometrial cancer, and may therefore be informative regarding endometrial cancer risk. This study investigated the association between endometrial cancer risk and markers of insulin resistance, namely adiponectin, leptin, the A:L ratio, insulin, fasting glucose, and the HOMA-IR. We analyzed data from 541 incident endometrial cancer cases and 961 frequency age-matched controls in a population-based case-control study in Alberta, Canada from 2002 to 2006. Participants completed interview-administered questionnaires were assessed for anthropometric measures, and provided 8-h fasting blood samples either pre- or postoperatively. Blood was analyzed for concentrations of leptin, adiponectin, and insulin by immunoassay, and fasting plasma glucose levels were determined by fluorimetric quantitative determination. Compared with the lowest quartile, the highest quartile of insulin and HOMA-IR was associated with 64% (95% confidence intervals (CI): 1.12-2.40) and 72% (95% CI: 1.17-2.53) increased risks of endometrial cancer, respectively, and the highest quartile of adiponectin was associated with a 45% (95% CI: 0.37-0.80) decreased risk after multivariable adjustments. Null associations were observed between fasting glucose, leptin and A:L, and endometrial cancer risk. This population-based study provides evidence for a role of insulin resistance in endometrial cancer etiology and may provide one possible pathway whereby obesity increases the risk of this common cancer. Interventions aimed at decreasing both obesity and insulin resistance may decrease endometrial cancer risk.

A prospective investigation of coffee drinking and endometrial cancer incidence

Coffee drinking may be associated with reduced risk of endometrial cancer; however, prospective data are limited. Further, it is not clear whether any association between coffee and endometrial cancer differs according to coffee caffeine content. The association of coffee drinking with incidence of endometrial cancer was evaluated among 226,732 women, aged 50-71, enrolled in the NIH-AARP Diet and Health Study who completed a baseline epidemiologic questionnaire. Following a mean 9.3 years of follow-up, data were available for 1,486 incident endometrial cancer cases. Cox proportional hazards models were used to estimate associations of coffee with endometrial cancer incidence. Sub-group analyses were performed according to smoking status, hormone therapy use (HT) and body habitus. Coffee drinking was inversely related to incidence of endometrial cancer (hazard ratio [HR] comparing drinking of >3 cups/day versus no cups = 0.64, 95% CI, 0.51-0.80; P(trend) = 0.0004). The association of coffee with endometrial cancer risk was apparent for consumption of both regular (HR per cup = 0.90, 95% CI, 0.86-0.95) and decaffeinated coffee (HR per cup = 0.93, 95% CI, 0.87-0.99). The relation of coffee with endometrial cancer incidence varied significantly by HT use (P(interaction) = 0.03) with an association only apparent among HT-never users (HR comparing drinking >3 cups/day versus no cups = 0.54, 95% CI, 0.41-0.72; P(trend) = 0.0005). Endometrial cancer incidence appears to be reduced among women that habitually drink coffee, an association that does not differ according to caffeine content.

Annual fasting plasma glucose variation increases risk of cancer incidence and mortality in patients with type 2 diabetes: the Taichung Diabetes Study

The study aims to examine whether the annual variations in fasting plasma glucose (FPG) measurements, represented by the coefficient of variation (CV), predict cancer incidence and mortality in the subsequent years independent of traditional risk factors of type 2 diabetic patients. A computerized database of patients with type 2 diabetes of 30 years old and older (n=4805) enrolled in the Diabetes Care Management Program of a medical center before 2006 was analyzed using a time-dependent Cox's proportional hazards regression model. The mortality rates for the first, second, and third tertiles of the first annual FPG-CV were 8.64, 12.71, and 30.82 per 1000 person-years respectively. After adjusting for mean FPG, HbA1c, and other risk factors, the annual FPG-CV was independently associated with cancer incidence, cancer mortality, and cancer incidence or mortality, and the corresponding hazard ratios for the third vs first tertile of the annual FPG-CV were 3.03 (1.98, 4.65), 5.04 (2.32, 10.94), and 2.86 (1.91, 4.29) respectively. The annual variation in FPG was a strong predictor of cancer incidence and mortality in type 2 diabetic patients; therefore, glucose variation may be important in the clinical practice of care management and cancer prevention.

Serum insulin-like, growth factor binding protein-related protein 1 (IGFBP-rP1) and endometrial cancer risk in Chinese women

Hyperinsulinemia and the metabolic syndrome confer increased risks of endometrial carcinoma. The roles of insulin, and, insulin-like growth factor-binding proteins (IGFBPs) in the etiology of endometrial carcinoma, remain unclear. We recruited 206 patients with endometrial carcinoma and 350 healthy women to a case-control study of fasting insulin and IGFBP-related protein 1 (IGFBP-rP1) in a Chinese tertiary centre. Patients with endometrial carcinoma had higher insulin concentrations (14.8 ± 16.7 vs. 8.1 ± 9.4 μU/mL; p < 0.001) and lower IGFBP-rP1 levels (17.5 ± 17.2 vs. 22.4 ± 22.8 μg/L; p = 0.018) than controls. High insulin and IGFBP-rP1 levels were both positively and negatively associated with endometrial cancer (odds ratio for the highest tertile versus the lowest tertile: insulin: 4.11; 95% CI = 2.61-6.47; IGFBP-rP1: 0.38; 95% CI = 0.24-0.60). Logistic regression analysis confirmed the associations between endometrial carcinoma and fasting insulin or IGFBP-rP1 after adjustments for age, BMI, serum glucose, cholesterol, triglycerides and high-density lipoprotein cholesterol (odds ratio for the highest tertile versus the lowest tertile: insulin: 2.13; 95% CI = 1.30-3.49; IGFBP-rP1: 0.57; 95% CI = 0.34-0.94). Hyperinsulinemia and high IGFBP-rP1 levels confer altered risks for endometrial carcinoma.

Endometrial abnormality in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy associated with infertility and metabolic disorder in women of reproductive age. Although the clinical and biochemical features are heterogeneous with individuals, the most widely accepted clinical characteristics of PCOS are oligo- or anovulation combined with hyperandrogenism. With the higher rate of implantation failure after induction of ovulation or higher risk of spontaneous miscarriage after pregnancy, the reduced fertility is apparently attributed not only to anovulation but also to endometrial dysfunction in patients with PCOS. Here we review the features of the endometrial abnormalities in women with PCOS. The ability to improve the endometrial functions is of potential therapeutic targets to increase reproductive outcome of women with PCOS.

Caffeinated coffee, decaffeinated coffee and endometrial cancer risk: a prospective cohort study among US postmenopausal women

There is plausible biological evidence as well as epidemiologic evidence to suggest coffee consumption may lower endometrial cancer risk. We evaluated the associations between self-reported total coffee, caffeinated coffee and decaffeinated coffee, and endometrial cancer risk using the Women's Health Initiative Observational Study Research Materials obtained from the National Heart, Lung, and Blood Institute Biological Specimen and Data Repository Coordinating Center. Our primary analyses included 45,696 women and 427 incident endometrial cancer cases, diagnosed over a total of 342,927 person-years of follow-up. We used Cox-proportional hazard models to evaluate coffee consumption and endometrial cancer risk. Overall, we did not find an association between coffee consumption and endometrial cancer risk. Compared to non-daily drinkers (none or <1 cup/day), the multivariable adjusted hazard ratios for women who drank ≥4 cups/day were 0.86 (95% confidence interval (CI) 0.63, 1.18) for total coffee, 0.89 (95% CI 0.63, 1.27) for caffeinated coffee, and 0.51 (95% CI 0.25, 1.03) for decaf coffee. In subgroup analyses by body mass index (BMI) there were no associations among normal-weight and overweight women for total coffee and caffeinated coffee. However among obese women, compared to the referent group (none or <1 cup/day), the hazard ratios for women who drank ≥2 cups/day were: 0.72 (95% CI 0.50, 1.04) for total coffee and 0.66 (95% CI 0.45, 0.97) for caffeinated coffee. Hazard ratios for women who drank ≥2 cups/day for decaffeinated coffee drinkers were 0.67 (0.43-1.06), 0.93 (0.55-1.58) and 0.80 (0.49-1.30) for normal, overweight and obese women, respectively. Our study suggests that caffeinated coffee consumption may be associated with lower endometrial cancer risk among obese postmenopausal women, but the association with decaffeinated coffee remains unclear.

Sucrose, high-sugar foods, and risk of endometrial cancer--a population-based cohort study

BACKGROUND

Consumption of high-sugar foods stimulates insulin production, which has been associated with endometrial cancer. Although a relationship between sucrose, high-sugar food consumption, and endometrial cancer risk is biologically plausible, this hypothesis has previously been explored in very few studies.

METHODS

We used data from the Swedish Mammography Cohort, including 61,226 women aged 40 to 74 years. We examined the association between consumption of total sucrose, high-sugar foods (at baseline 1987-1990 and 1997) and endometrial cancer risk by using Cox proportional hazards models to estimate incidence rate ratios (RR) with 95% CI.

RESULTS

During 18.4 years of follow-up, 729 participants were diagnosed with incident endometrial cancer. Total sucrose intake and consumption of sweet buns and cookies was associated with increased risk of endometrial cancer. RRs (with 95% CIs) for consuming more than 35 grams of sucrose per day and consuming sweet buns and cookies more than 3 times per week were 1.36 (1.04-1.77) and 1.42 (1.15-1.75) as compared with less than 15 grams of sucrose per day and consuming sweet buns and cookies less than 0.5 times per week, respectively. RRs for consuming more than 15 grams of sucrose per day as compared with 15 grams or less were 1.97 (1.27-3.04) among obese women and 1.56 (1.20-2.04) among women with low fat intake.

CONCLUSIONS

These data indicate that sucrose intake and consumption of sweet buns and cookies may be associated with increased risk of endometrial cancer.

IMPACT

Given the high intake of sweetened foods, these results have public health implications in terms of prevention of endometrial cancer.

Endometrial thickness, uterine, and ovarian ultrasonographic features in adolescents with polycystic ovarian syndrome

OBJECTIVE

Our aim was to evaluate uterine and ovarian ultrasonographic features including endometrial thickness (ET) in adolescent females with PCOS, which is limited in this population.

METHODS

We performed a retrospective chart review of young females (n=51) ranging in age from 10 to 18 years with the diagnosis of PCOS. Clinical, biochemical and pelvic sonography data were reviewed. Sonographic data included uterine parameters of ET, length, and volume as well as ovarian volume and follicular morphologic features.

RESULTS

Data in 51 girls were analyzed. Menstrual periods were reported as irregular in 26/51 (50.9%), amenorrheic in 19/51 (37.2%), regular in 4/51 (7.8%) and metrorrhagia in 2/51 (3.9%). Uterine features revealed that the endometrial stripe was enlarged (>7mm) in 16/51 (31.4%) of girls, all with homogeneous appearance. The uterine length was lower than normal in 22/51 (43.1%) of girls, normal in 21/51 (41.2%), and higher than normal in 8/51 (15.7%). Uterine volume was normal in 31/51 (60.7%) and higher in 20/51 (39.3%) of girls. Enlarged ovarian volume was found in 22/51 (43%) of patients. Mean ovarian volumes were 16.1cm(3) and 13.1cm(3) in bilateral and unilaterally enlarged ovaries, respectively. The morphology of ovarian follicles was studied in a subset of 40 patients. The location of ovarian follicles was peripheral in 81% and mixed in 19%. The number of follicles was also examined in 43 patients. They were few (<5) in 12%, moderate (5-10) in 5% and multiple (>10) in 84% cases. There was the presence of at least one >10mm cyst in 25% of girls.

CONCLUSION

Majority of the adolescents with PCOS demonstrated multiple peripheral ovarian follicles, with large ovarian volumes in some, indicating an important role of ultrasonography in the diagnosis of PCOS, even at a younger age. Endometrial thickness, uterine length, ovarian size, and follicular morphology should be carefully examined in cases of adolescent PCOS.

Alcohol intake and endometrial cancer risk: a meta-analysis of prospective studies

Background:

Studies on alcohol intake in relation to endometrial cancer risk have produced inconsistent results.

Methods:

For a meta-analysis, we identified cohort studies of alcohol and endometrial cancer by a literature search of Pub-Med and Embase up to 1 March 2010 and by searching the reference lists of relevant articles.

Results:

Seven cohort studies, including 1 511 661 participants and 6086 endometrial cancer cases, were included in the dose–response random-effect meta-regression model. Compared with non-drinkers, women drinking less than 1 drink of alcohol (13 g of ethanol) per day had a lower risk for endometrial cancer; this risk was lower by 4% (95% confidence interval (95% CI): 0.93–1.00) for consumption up to 0.5 drink per day and by 7% (95% CI: 0.85–1.02) for consumption up to 1 drink. However, we found evidence of an increased risk for endometrial cancer for intakes higher than two alcoholic drinks per day: compared with non-drinkers, the risk was higher by 14% (95% CI: 0.95–1.36) for 2–2.5 drinks per day and by 25% (95% CI: 0.98–1.58) for >2.5 drinks per day.

Conclusion:

Our meta-analysis indicates a possible J-shaped relationship between alcohol intake and endometrial cancer risk.

Coffee drinking and risk of endometrial cancer--a population-based cohort study

Coffee drinking has been reported to have beneficial effects on insulin resistance, which has been directly associated with endometrial cancer. Although a relationship between coffee consumption and endometrial cancer risk is biologically plausible, this hypothesis has been previously explored in only 2 prospective studies, with a small number of cases. We used data from the Swedish Mammography Cohort, a population-based prospective cohort study of 60,634 women. During 17.6 years of follow-up, 677 participants were diagnosed with incident endometrial cancer (adenocarcinoma). We examined the association between self-reported coffee consumption (at baseline 1987-90 and in 1997) and endometrial cancer risk using Cox proportional hazards models. Each additional cup (200 g) of coffee per day was associated with a rate ratio (RR) of 0.90 [95% confidence interval (CI), 0.83-0.97]. In women drinking 4 or more cups of coffee a day, the RR for the risk reduction of endometrial cancer was 0.75 (95% CI, 0.58-0.97) when compared with those who drank 1 cup or less. The association seemed largely confined to overweight and obese women, who showed a respective risk reduction of 12% (95% CI, 0-23%) and 20% (95% CI, 7-31%) for every cup of coffee, but was not observed among normal-weight women. There was a statistically significant interaction between coffee consumption and body mass index (p(interaction) < 0.001). These data indicate that coffee consumption may be associated with decreased risk of endometrial cancer, especially among women with excessive body weight. If confirmed by other prospective studies, these results are of major public health significance.

Long-term alcohol consumption and risk of endometrial cancer incidence: a prospective cohort study

Alcohol consumption has been hypothesized to increase the risk of endometrial cancer. We used data from the prospective population-based Swedish Mammography Cohort including 61,226 women to examine the association between alcohol and endometrial cancer incidence. Alcohol consumption was assessed with validated food frequency questionnaires at baseline 1987 to 1990 and at follow-up in 1997. During a mean follow-up of 17.6 years, 687 endometrial cancer cases were identified in the Swedish cancer registries. We found no association between alcohol consumption and endometrial cancer risk after adjustment for age, body mass index, and smoking. The multivariable rate ratios (95% confidence intervals) for the three upper categories of long-term alcohol consumption as compared with no consumption were 1.01 (0.84-1.22) for <3.4 g/d, 1.01 (0.80-1.27) for 3.4 to 9.9 g/d, and 1.09 (0.71-1.67) for >or=10 g/d, respectively. The association did not differ by age, body mass index, folic acid intake, or postmenopausal hormone use in stratified analysis. In conclusion, our results suggest that low alcohol consumption (up to one drink per day) is unlikely to substantially influence risk of endometrial cancer.

A prospective evaluation of insulin and insulin-like growth factor-I as risk factors for endometrial cancer

Obesity is a major risk factor for endometrial cancer, a relationship thought to be largely explained by the prevalence of high estrogen levels in obese women. Obesity is also associated with high levels of insulin, a known mitogen. However, no prospective studies have directly assessed whether insulin and/or insulin-like growth factor-I (IGF-I), a related hormone, are associated with endometrial cancer while accounting for estrogen levels. We therefore conducted a case-cohort study of incident endometrial cancer in the Women's Health Initiative Observational Study, a prospective cohort of 93,676 postmenopausal women. The study involved all 250 incident cases and a random subcohort of 465 subjects for comparison. Insulin, total IGF-I, free IGF-I, IGF-binding protein-3, glucose, and estradiol levels were measured in fasting baseline serum specimens. Cox models were used to estimate associations with endometrial cancer, particularly endometrioid adenocarcinomas, the main histologic type (n = 205). Our data showed that insulin levels were positively associated with endometrioid adenocarcinoma [hazard ratio contrasting highest versus lowest quartile (HR(q4-q1)), 2.33; 95% confidence interval (95% CI), 1.13-4.82] among women not using hormone therapy after adjustment for age and estradiol. Free IGF-I was inversely associated with endometrioid adenocarcinoma (HR(q4-q1), 0.53; 95% CI, 0.31-0.90) after adjustment for age, hormone therapy use, and estradiol. Both of these associations were stronger among overweight/obese women, especially the association between insulin and endometrioid adenocarcinoma (HR(q4-q1), 4.30; 95% CI, 1.62-11.43). These data indicate that hyperinsulinemia may represent a risk factor for endometrioid adenocarcinoma that is independent of estradiol. Free IGF-I levels were inversely associated with endometrioid adenocarcinoma, consistent with prior cross-sectional data.

Dichloroacetate induces apoptosis in endometrial cancer cells

PURPOSE

A recent landmark study demonstrated that Dichloroacetate (DCA) treatment promoted apoptosis in lung, breast, and glioblastoma cancer cell lines by shifting metabolism from aerobic glycolysis to glucose oxidation coupled with NFAT-Kv1.5 axis remodeling. The objective of this study was to determine whether DCA induces apoptosis in endometrial cancer cells and to assess apoptotic mechanism.

METHODS

A panel of endometrial cancer cell lines with varying degrees of differentiation was treated with DCA and analyzed for apoptosis via flow cytometry. Biological correlates such as gene expression, intracellular Ca(2+), and mitochondrial membrane potential were examined to assess apoptotic mechanism.

RESULTS

Initiation of apoptosis was observed in five low to moderately invasive cancer cell lines including Ishikawa, RL95-2, KLE, AN3CA, and SKUT1B while treatment had no effect on non-cancerous 293T cells. Two highly invasive endometrial adenocarcinoma cell lines, HEC1A and HEC1B, were found to be resistant to DCA-induced apoptosis. Apoptotic responding cell lines had a significant increase in early and late apoptotis, a decrease in mitochondrial membrane potential, and decreased Survivin transcript abundance, which are consistent with a mitochondrial-regulated mechanism. DCA treatment decreased intracellular calcium levels in most apoptotic responding cell lines which suggests a contribution from the NFAT-Kv1.5-mediated pathway. DCA treatment increased p53 upregulated modulator of apoptosis (PUMA) transcripts in cell lines with an apoptotic response, suggesting involvement of a p53-PUMA-mediated mechanism.

CONCLUSIONS

Dichloroacetate effectively sensitizes most endometrial cancer cell lines to apoptosis via mitochondrial, NFAT-Kv1.5, and PUMA-mediated mechanisms. Further investigation of the cancer therapeutic potential of DCA is warranted.

Hormonal heterogeneity of endometrial cancer

Endometrial cancer is the most common malignant tumor of the female genital tract in the developed world. Increasing evidence suggests that the majority of cases can be divided into two different types ofendometrial cancer based on clinico-pathological and molecular characteristics. Type I is associated with an endocrine milieu of estrogen predominance. These tumors are ofendometroid histology and develop from endometrial hyperplasia. They have good prognosis and are sensitive to endocrine treatment. Type II endometrial cancers are not associated with a history of unopposed estrogens and develop from the atrophic endometrium of elderly women. Mainly, they are of serous papillary or clear cell morphology, have a poor prognosis and do not react to endocrine treatment. Both types of endometrial cancer probably differ markedly with regard to the molecular mechanisms of transformation. The transition from normal endometrium to a malignant tumor is thought to involve a stepwise accumulation of alterations in cellular mechanisms leading to dysfunctional cell growth. This chapter reviews the current knowledge of the molecular mechanisms commonly associated with development of type I and type II endometrial cancer.

Diabetes mellitus and risk of endometrial cancer: a meta-analysis

AIMS/HYPOTHESIS

Diabetes has been associated with a statistically significantly increased risk of endometrial cancer in most, but not all studies. To provide a quantitative assessment of the association between diabetes and risk of endometrial cancer, we conducted a meta-analysis of case-control studies and cohort studies.

SUBJECTS AND METHODS

We identified studies by a literature search of PubMed and Embase through to January 2007 and by searching the reference lists of relevant articles. Summary relative risks (RRs) with 95% CIs were calculated using random-effects model.

RESULTS

The analysis of diabetes (largely type 2) and endometrial cancer is based on 16 studies (three cohort and 13 case-control studies), including 96,003 participants and 7,596 cases of endometrial cancer. Twelve of the studies showed a statistically significantly increased risk and four a non-significant increased risk of endometrial cancer. In our meta-analysis we found that diabetes was statistically significantly associated with an increased risk of endometrial cancer (summary RR 2.10, 95% CI 1.75-2.53). The risk estimates were somewhat stronger among case-control (RR 2.22, 95% CI 1.80-2.74) than among cohort studies (RR 1.62, 95% CI 1.21-2.16), stronger among studies adjusting only for age (RR 2.74, 95% CI 1.87-4.00) compared with multivariate adjustment (RR 1.92, 95% CI 1.58-2.33) and slightly lower in studies performed in the USA than in those performed Europe. The analysis of type 1 diabetes and endometrial cancer was based on three studies and found a statistically significant positive association (summary RR 3.15, 95%CI 1.07-9.29).

CONCLUSIONS/INTERPRETATION

Results from the meta-analysis support a relationship between diabetes and increased risk of endometrial cancer.

Diabetes and risk of endometrial cancer: a population-based prospective cohort study

Although there is accumulating evidence that hyperinsulinemia in the context of insulin resistance is associated with carcinogenesis, only one prospective study of endometrial cancer incidence, in relation to diabetes, addressed this issue and showed no significant positive association. No previous study has investigated whether physical activity can modify the association between diabetes and endometrial cancer. We examined the association between diabetes and incidence of endometrial cancer and the potential effect modification by obesity and physical activity in the Swedish Mammography Cohort, a prospective cohort of 36,773 women, including 225 incident endometrial adenocarcinoma cases. After adjustments, the relative risk (RR) for endometrial cancer among women with diabetes comparing with nondiabetic women was 1.94 [95% confidence interval (95% CI), 1.23-3.08]. Among obese diabetics, the RR was 6.39 (95% CI, 3.28-12.06) compared with nonobese nondiabetic women. Among diabetics with low physical activity, the RR for endometrial cancer was 2.80 (95% CI, 1.62-4.85) compared with physically active nondiabetic women. Obese diabetics with low physical activity had a RR of 9.61 (95% CI, 4.66-19.83) compared with normal weight nondiabetic women with high physical activity. Diabetes was associated with a 2-fold increased risk, and combination of diabetes with obesity and low physical activity was associated with a further increased risk for endometrial cancer. Interventions to reduce body weight and increase physical activity may have important implications in terms of prevention of endometrial cancer and future management of diabetic subjects.

P-LAP/IRAP-induced cell proliferation and glucose uptake in endometrial carcinoma cells via insulin receptor signaling

Background

Hyperglycemia or hyperinsulinemia contributes to poorer endometrial cancer survival. It was shown that P-LAP/IRAP translocates to the plasma membrane in response to insulin stimulation. Recently, we demonstrated that P-LAP/IRAP is associated with a poor prognosis in endometrial adenocarcinoma patients. The aim of this study was to examine whether the malignant potential of endometrial cancer enhanced by P-LAP/IRAP is due to increased glucose uptake via the P-LAP/IRAP-mediated activation of insulin signaling.

Methods

We transfected P-LAP/IRAP cDNA into A-MEC cells (endometrial adenocarcinoma cell line), and A-MEC-LAP cells expressed a remarkably high level of GLUT4 proteins.

Results

³H-2-deoxyglucose uptake which responds to insulin in A-MEC-LAP cells was significantly higher than that of A-MEC-pc cells. A-MEC-LAP cells exhibited a significant growth-stimulatory effect compared to A-MEC-pc cells. A-MEC-LAP cells expressed a remarkably high level of p85PI3K protein compared to A-MEC-pc cells, and showed a higher degree of AKT phosphorylation by insulin stimulation.

Conclusion

In summary, P-LAP/IRAP was involved in the increasing malignant potential of endometrial cancer mediated by insulin. P-LAP/IRAP was suggested to be a potential new target of molecular-targeted therapy for endometrial cancer.