Body mass index: Relationship to clinical, pathologic and features of microsatellite instability in endometrial cancer

Context-dependent environmental associations with endometrial cancer histotype and genotype

OBJECTIVE

MLH1 loss due to MLH1 methylation, detected during Lynch syndrome screening, is one of the most common molecular changes in endometrial cancer. It is well established that environmental influences such as nutritional state can impact gene methylation, both in the germline and in a tumor. In colorectal cancer and other cancer types, aging is associated with changes in gene methylation. The objective of this study was to determine if there was an association between aging or body mass index on MLH1 methylation in sporadic endometrial cancer.

METHODS

A retrospective review of patients with endometrial cancer was performed. Tumors were screened for Lynch syndrome via immunohistochemistry, with MLH1 methylation analysis performed when there was loss of MLH1 expression. Clinical information was abstracted from the medical record.

RESULTS

There were 114 patients with mismatch repair deficient tumors associated with MLH1 methylation, and 349 with mismatch repair proficient tumors. Patients with mismatch repair deficient tumors were older than those whose tumors were proficient. Mismatch repair deficient tumors had a higher incidence of lymphatic/vascular space invasion. When stratified by endometrioid grade, associations with body mass index and age became apparent. Patients with endometrioid grades 1 and 2 tumors and somatic mismatch repair deficiency were significantly older, but body mass index was comparable with that of the mismatch repair intact group. For endometrioid grade 3, patient age did not significantly vary between the somatic mismatch repair deficient group and the mismatch repair intact group. In contrast, body mass index was significantly higher in the patients with grade 3 tumors with somatic mismatch repair deficiency.

CONCLUSION

The relationship of MLH1 methylated endometrial cancer with age and body mass index is complex and somewhat dependent on tumor grade. As body mass index is modifiable, it is possible that weight loss induces a 'molecular switch' to alter the histologic characteristics of an endometrial cancer.

An effective algorithm to detect the possibility of being MSI phenotype in endometrial cancer given the BMI status and histological subtype: a statistical study

Purpose

In endometrial cancer, the incidence of mutations in mismatch repair genes (MMR) is estimated at 17–30%. Patients with alterations at this level (MSI) are known to have different clinical and anatomopathological characteristics than those without this genetic alteration (MSS). In this study, we aim to identify the MSI phenotype in patients who underwent hysterectomy for endometrial cancer. We assessed the correlation of this phenotype with anatomoclinical parameters such as obesity and histological subtype.

Methods/patients

Clinical and anatomopathological data were collected from 147 patients diagnosed with endometrial cancer and an immunohistochemical study of MMR system proteins was performed. PMS2 and MSH6 proteins were evaluated as primary screening and subsequent evaluation of MLH1 and MSH6, respectively, if the former were negative. Statistical association between the anatomopathological data and the immunohistochemical result was analyzed.

Results and conclusions

22.4% of our patients were MSI phenotype. We obtained statistically significant differences by multivariate analysis between endometrioid subtype and higher FIGO classification grade with MSI phenotype and obesity with MSS phenotype. Given these statistical results, we propose a function for predicting the probability of being MSI phenotype taking into account the histological subtype (endometrioid/non-endometrioid carcinoma) and FIGO grade as well as obesity. This prediction may be useful prior to hysterectomy, for genetic study of the MLH1 promoter and subsequent genetic counseling.

Endometrial cancer in Lynch syndrome

Lynch syndrome (LS) is an autosomal dominant inherited disease caused by germline pathogenic variants (PVs) in mismatch repair (MMR) genes. LS-associated endometrial cancer (LS-EC) is the most common extraintestinal sentinel cancer caused by germline PVs in MMR genes, including MLH1, MSH2, MSH6 and PMS2. The clinicopathologic features of LS-EC include early age of onset, lower body mass index (BMI), endometrioid carcinoma and lower uterine segment involvement. There has been significant progress in screening, diagnosis, surveillance, prevention and treatment of LS-EC. Many studies support universal screening for LS among patients with EC. Screening mainly involves a combination of traditional clinical criteria and molecular techniques, including MMR-immunohistochemistry (MMR-IHC), microsatellite instability (MSI) testing, MLH1 promoter methylation testing and gene sequencing. The effectiveness of endometrial biopsy and transvaginal ultrasound (TVS) for clinical monitoring of asymptomatic women with LS are uncertain yet. Preventive strategies include hysterectomy and bilateral salpingo-oophorectomy (BSO) as well as chemoprophylaxis using exogenous progestin or aspirin. Recent research has revealed the benefits of immunotherapy for LS-EC. The NCCN guidelines recommend pembrolizumab and nivolumab for treating patients with advanced or recurrent microsatellite instability-high (MSI-H)/mismatch repair-deficient (dMMR) EC.

Significance of atypical endometrial cells in women younger than 40 years of age

INTRODUCTION

The presence of atypical endometrial cells in the Papanicolaou (Pap) test has been associated with an increased rate of endometrial malignancy, with reported rates ranging from 14% to 47%. However, most reported studies have focused on patients who were aged >40 years. The purpose of the present study was to investigate the clinical significance of identifying atypical endometrial cells in Pap test samples in women aged <40 years of age.

MATERIALS AND METHODS

A search of the cytology Pap test database was performed from 2000 to 2014 using the keywords "atypical endometrial cells" or "atypical glandular cells favor endometrial origin" in women aged <40 years. The available ThinPrep slides were reviewed. The patients' clinical presentation, follow-up endometrial biopsy findings, treatment, and clinical follow-up data were recorded. Endometrial carcinoma tissue sections were screened for Lynch syndrome.

RESULTS

The database search yielded 63 study cases. Of these 63 patients, 52 had subsequently undergone endometrial biopsy. Of the 52 patients with follow-up biopsy findings available, 9 (17.3%) had premalignant (5 with atypical hyperplasia) or malignant (4 with endometrioid adenocarcinoma) lesions. In addition, 16 patients (30.8%) had other endometrial pathologic features. The 9 patients with premalignant or malignant endometrial lesions (8 white, 1 black) were overweight or obese; 3 of the patients did not have any clinical symptoms. All 4 patients with endometrioid adenocarcinoma had negative Lynch syndrome screening findings.

CONCLUSIONS

Our results suggest that it is important to recognize the presence of atypical endometrial cells in the Pap tests from young patients, given its association with the finding of premalignant and malignant pathologic features in subsequent endometrial biopsies.

Endocrinology of obese and nonobese endometrial cancer patients: is there role of tumor molecular-biological type?

Aim: To compare endocrine characteristics of  endometrial cancer (EC) patients based on recent molecular EC types classification. Materials & methods: A total of 234 treatment-naive EC patients as well their tumors were studied. Results: Patients with POLE mutations demonstrated tendency to lower body mass index (BMI) and higher serum estradiol. Patients with p53 overexpression were older and had higher diabetes incidence. In the without characteristic molecular profile group there was no difference in fasting serum insulin, estradiol and testosterone levels between women with BMI ≥30.0 and <30.0. The mismatch repair deficient group patients had a tendency toward later menarche compared with the without characteristic molecular profile group one. Conclusion: Studied endocrine characteristics are associated with BMI or tumor molecular-biological type that might be relevant to EC genesis, course and prognosis.

Impact of obesity and overweight on DNA stability: Few facts and many hypotheses

Health authorities are alarmed worldwide about the increase of obesity and overweight in the last decades which lead to adverse health effects including inflammation, cancer, accelerated aging and infertility. We evaluated the state of knowledge concerning the impact of elevated body mass on genomic instability. Results of investigations with humans (39 studies) in which DNA damage was monitored in lymphocytes and sperm cells, are conflicting and probably as a consequence of heterogeneous study designs and confounding factors (e.g. uncontrolled intake of vitamins and minerals and consumption of different food types). Results of animal studies with defined diets (23 studies) are more consistent and show that excess body fat causes DNA damage in multiple organs including brain, liver, colon and testes. Different molecular mechanisms may cause genetic instability in overweight/obese individuals. ROS formation and lipid peroxidation were found in several investigations and may be caused by increased insulin, fatty acid and glucose levels or indirectly via inflammation. Also reduced DNA repair and formation of advanced glycation end products may play a role but more data are required to draw firm conclusions. Reduction of telomere lengths and hormonal imbalances are characteristic for overweight/obesity but the former effects are delayed and moderate and hormonal effects were not investigated in regard to genomic instability in obese individuals. Increased BMI values affect also the activities of drug metabolizing enzymes which activate/detoxify genotoxic carcinogens, but no studies concerning the impact of these alterations of DNA damage in obese individuals are available. Overall, the knowledge concerning the impact of increased body weight and DNA damage is poor and further research is warranted to shed light on this important issue.

Endometrial cancer risk and survival by tumor MMR status

Objective

The risk of developing endometrial cancer (EC) and/or survival following a diagnosis of EC might differ by tumor DNA mismatch repair (MMR) status. We assessed the association between tumor MMR status (classified as MMR-proficient, somatic MMR-deficient, germline MMR-deficient) and the risk of developing EC and survival following a diagnosis of EC.

Methods

We analyzed data from women who participated in the Australian National Endometrial Cancer Study (ANECS) conducted between 2005 and 2007. Risk analyses (698 cases/691 population controls) utilized sociodemographic and lifestyle information obtained from telephone interviews at recruitment. For survival analyses (728 cases), patients' clinical data was abstracted from medical records, and survival data were obtained via linkage with the Australian National Death Index. We used logistic regression analysis to evaluate the associations between tumor MMR status and EC risk, and proportional hazards models to perform survival analyses with adjustment of known prognostic factors.

Results

Established risk factors for EC did not differ significantly by tumor MMR status. In analyses including all EC subtypes, overall and EC-specific survival did not differ by tumor MMR status. Among women with the most common endometrioid subtype, EC-specific survival was worse for women with somatic MMR-deficient EC compared to women with MMR-proficient EC (hazard ratio [HR]=2.18; 95% confidence interval [CI]=1.19–4.01).

Conclusion

The risk of EC is not associated with MMR status. Accurate separation of germline from somatic causes of MMR deficiency suggests that patients with endometrioid subtype somatic MMR-deficient tumors have poorer EC-specific survival than those with MMR-proficient tumors, after accounting for other prognostic factors.

Endometrial cancer evolution: new molecular-biologic types and hormonal-metabolic shifts

The question hidden in the title of this manuscript (whether the topic develops or remains constant) is important for all areas of science. It is also a serious problem for endometrial cancer (EC) study. In recent times the incidence of EC gradually increases in parallel with obesity epidemics. The main point of this review was evaluation of changes in EC area in last few decades, which are not only seen in tumor incidence, but also in its biology, hormonal-metabolic characteristics of patients and in the ratio of risk and anti-risk factors. One can hope that data accumulated recently and summarized here under the notion of EC evolution will find its use for advancement of EC prevention and treatment.

Importance of PCR-based Tumor Testing in the Evaluation of Lynch Syndrome-associated Endometrial Cancer

Lynch syndrome (LS) is a hereditary cancer syndrome caused by a germline mutation in a DNA mismatch repair gene, usually MLH1, MSH2, MSH6, or PMS2. The most common cancers associated with LS are colorectal adenocarcinoma and endometrial carcinoma. Identification of women with LS-associated endometrial cancer is important, as these women and their affected siblings and children are at-risk of developing these same cancers. Germline testing of all endometrial cancer patients is not cost effective, and screening using young age of cancer diagnosis and/or presence of family history of syndrome-associated is underutilized and ineffective. Therefore, most groups now advocate for tumor tissue testing to screen for LS, with germline testing targeted to women with abnormal tissue testing results. Immunohistochemistry for MLH1, MSH2, MSH6, and PMS2 is used in many clinical laboratories for this tumor screening step, as immunohistochemistry is relatively inexpensive and is technically more accessible for smaller clinical labs. PCR-based tissue testing, whereas technically more challenging, does play an important role in the identification of these patients. MLH1 methylation analysis identifies women with tumor MLH1 loss who likely have sporadic endometrial cancer and do not need heightened cancer prevention surveillance. High levels of microsatellite instability have been identified in tumors with retained positive expression of mismatch repair proteins. Somatic sequencing of mismatch repair genes from tumor DNA, whereas not currently available in most clinical laboratories, is helpful in resolution of cases in which germline sequencing fails to identify a mutation in a mismatch repair gene. The tumor tissue testing approach can help to identify most women at-risk for germline mutations in a LS gene, but not all patients will be captured using this approach. Clinical suspicion can still play a pivotal role in accurately identifying a subset of these patients.

Bokhman Redux: Endometrial cancer "types" in the 21st century

In 1983 Jan V. Bokhman, M.D. published a landmark paper entitled "Two Pathogenetic Types of Endometrial Carcinoma" in which an enduring dualistic view of endometrial cancer was first proposed. "Type I" cancers are thought to represent estrogen driven mostly low grade endometrioid tumors strongly associated with obesity and other components of the metabolic syndrome. "Type II" cancers represent higher grade non-endometrioid tumors for which the latter associations are less significant. Basic tenets of this dichotomy including significant prognostic differences have been abundantly confirmed by later literature. The construct has in turn contributed a useful framework for decades of teaching and scientific advancement across disciplines. However, recent large epidemiologic studies indicate a more complex web of risk factors with obesity and hormones likely playing an important role across the entire endometrial cancer histologic and clinical spectrum. Moreover, high quality molecular data and refinements in pathologic classification challenge any simplistic classification of endometrial cancer. For example, the Cancer Genome Atlas (TCGA) recently defined four clinically distinct endometrial cancer types based on their overall mutational burden, specific p53, POLE and PTEN mutations, microsatellite instability and histology. Additionally, new histologic categories with clear prognostic implications have been accepted and it is becoming evident from an epidemiologic point of view that metabolic factors may play an important role in endometrial cancer overall. While Bokhman's intuitive dualistic model remains relevant when working with large registries and databases lacking granular information; most other efforts should integrate clinical, pathological and molecular specifics into more nuanced classifications.

Clinical Challenges Associated with Universal Screening for Lynch Syndrome-Associated Endometrial Cancer

Universal testing for Lynch syndrome is now a routine component of the diagnostic work-up of endometrial cancer patients. The purpose of this study was to identify prospectively the barriers to universal screening based on a tissue testing approach [microsatellite instability (MSI) analysis, IHC for DNA mismatch repair proteins, and MLH1 methylation analysis]. Endometrial carcinoma patients (n = 213) prospectively underwent microsatellite instability and IHC testing for expression of DNA mismatch repair (MMR) proteins. Patients with low (MSI-L) or high (MSI-H) levels of tumor MSI or immunohistochemical loss of MLH1 (and absent MLH1 methylation), MSH2, MSH6, or PMS2 were referred to a genetic counselor for consideration of germline testing. Six discordances (3.1% of tested cases) between IHC and MSI were identified. Half of these exhibited heterogeneous immunohistochemical loss of MLH1/PMS2 and were microsatellite stable (MSS). Of the remaining cases, one was MSS with immunohistochemical loss of MSH6, one was MSS with immunohistochemical loss of MLH1/PMS2 and absent MLH1 promoter methylation, and one was MSI-H with intact expression of DNA MMR proteins. Four patients had MSI-L tumors with intact immunohistochemical protein expression; the clinical significance of MSI-L in endometrial cancer is unclear. Eight patients did not have germline mutations despite tissue testing suggesting Lynch syndrome. Including cases with insufficient tissue for testing and patients declining tissue or germline testing, we encountered significant barriers to universal screening in 13.6% of screened patients (29/213) that preclude designation of a tumor as sporadic or hereditary. Cancer Prev Res; 10(2); 108-15. ©2016 AACR.

Endometrial cancer risk factors among Lynch syndrome women: a retrospective cohort study

BACKGROUND

Lynch syndrome (LS) is associated with a significant lifetime risk of endometrial cancer (EC). There are limited data on factors modifying the EC risk in LS patients.

METHODS

The study cohort included 136 LS mutation-positive women. Exposure data were collected by postal questionnaires. Cox regression model was used to estimate the associations between lifestyle, hormonal, reproductive and medical factors and the risk of EC.

RESULTS

Increased EC risk was associated with type II diabetes and hypercholesterolaemia in univariable (HR 3.21, (95% CI 1.34-7.78), P=0.009 and HR 2.08, (95% CI 1.11-3.90), P=0.02; respectively) and with diabetes and duration of hormone replacement therapy (HRT) in multivariable analysis (HR 4.18 (95% CI 1.52-11.52), P=0.006 and HR 1.07 (95% CI 1.02-1.13), P=0.010; respectively).

CONCLUSIONS

Prevention of diabetes and avoiding long-duration HRT are potential targets for reduction of EC risk in women with LS.

Insulinemia, heterogeneity of obesity and the risk of different types of endometrial cancer: existing evidence

Due to a number of reasons, endometrial cancer is a point of interest not only for oncologists, but also for a variety of specialists - especially endocrinologists. The endocrinology of endometrial cancer can be firmly divided into two categories - steroid and non-steroid. The steroid approach dominated during several decades due to hyperestrogenization signs observed in some patients. The balance was only regained in the last 15 years, when the role of diabetes and insulin resistance began to draw attention. This review aims to provide an update on connections between insulinemia (insulin resistance) and different obesity phenotypes as well to discuss their relation to development of endometrial cancer, its clinical-morphological features and the increasing number of its molecular-biological subtypes.

Microsatellite instability and ploidy status define three categories with distinctive prognostic impact in endometrioid endometrial cancer

Microsatellite instability (MSI) and aneuploidy are inversely related phenomena. We tested whether ploidy status influences the clinical impact of MSI in endometrioid endometrial cancer (EEC). We analyzed 167 EECs for MSI and ploidy. Tumors were classified in three categories according to MSI and ploidy status. Associations with clinicopathological and molecular variables, survival, and treatment response were assessed.

All MSI tumors (23%) were scored as diploid, and 14% of microsatellite stable (MSS) tumors presented aneuploidy. MSI tumors associated with older age at diagnosis, non-obesity, high histological grade, and advanced surgical stage. MSS-aneuploid tumors also associated with higher grade and advanced stage. In multivariate survival analysis MSI did not influence disease-free survival (DFS) or cancer-specific survival (CSS). However, when just diploid tumors were considered for the analysis, MSI significantly contributed to worse DFS and CSS, and the same was observed for aneuploidy when MSS tumors were analyzed alone. In diploid tumors, a differential response to postoperative radiotherapy (RT) was observed according to MSI, since it predicted poor DFS and CSS in the multivariate analysis.

We conclude that ploidy status influences the clinical impact of MSI in EEC. Among diploid tumors those with MSI have poor clinical outcome and respond worse to RT.

Utility of MLH1 methylation analysis in the clinical evaluation of Lynch Syndrome in women with endometrial cancer

Clinical screening criteria, such as young age of endometrial cancer diagnosis and family history of signature cancers, have traditionally been used to identify women with Lynch Syndrome, which is caused by mutation of a DNA mismatch repair gene. Immunohistochemistry and microsatellite instability analysis have evolved as important screening tools to evaluate endometrial cancer patients for Lynch Syndrome. A complicating factor is that 15-20% of sporadic endometrial cancers have immunohistochemical loss of the DNA mismatch repair protein MLH1 and high levels of microsatellite instability due to methylation of MLH1. The PCR-based MLH1 methylation assay potentially resolves this issue, yet many clinical laboratories do not perform this assay. The objective of this study was to determine if clinical and pathologic features help to distinguish sporadic endometrial carcinomas with MLH1 loss secondary to MLH1 methylation from Lynch Syndrome-associated endometrial carcinomas with MLH1 loss and absence of MLH1 methylation. Of 337 endometrial carcinomas examined, 54 had immunohistochemical loss of MLH1. 40/54 had MLH1 methylation and were designated as sporadic, while 14/54 lacked MLH1 methylation and were designated as Lynch Syndrome. Diabetes and deep myometrial invasion were associated with Lynch Syndrome; no other clinical or pathological variable distinguished the 2 groups. Combining Society of Gynecologic Oncology screening criteria with these 2 features accurately captured all Lynch Syndrome cases, but with low specificity. In summary, no single clinical/pathologic feature or screening criteria tool accurately identified all Lynch Syndrome-associated endometrial carcinomas, highlighting the importance of the MLH1 methylation assay in the clinical evaluation of these patients.

Does honey have the characteristics of natural cancer vaccine?

Honey could be considered the most sustainable food produced naturally. It contains sugars, vitamins, minerals and has high anti-oxidant activities. Cancer is on the rise in most countries. Carcinogenesis is a multi-step process and has multi-factorial causes. Among these are low immune status, chronic infection, chronic inflammation, chronic nonhealing ulcers, smoking, obesity etc. Published studies thus far have shown that honey improves immune status, has anti-inflammatory and anti-microbial properties and promotes healing of chronic ulcers and wounds and scavenge toxic free radicals. Recently honey has been shown to have anti-cancer properties in cell cultures and in animal models. The mechanisms suggested include induction of apoptosis, disruption of mitochondrial membrane potential and cell cycle arrest. Though sugar is predominant in honey which itself is thought to be carcinogenic, it is understandable that its beneficial effect as anti-cancer agent raises skeptics. With increasing number of people seeking therapy from nature, this area of research has recently gained attention.

Evaluation of clinical criteria for the identification of Lynch syndrome among unselected patients with endometrial cancer

Clinical criteria, primarily young age of cancer onset and family history of signature cancers, have been developed to identify individuals at elevated risk for Lynch syndrome with the goals of early identification and cancer prevention. In 2007, the Society of Gynecologic Oncology (SGO)-codified criteria for women presenting with gynecologic cancers. These criteria have not been validated in a population-based setting. For 412 unselected endometrial cancers, immunohistochemical expression of DNA mismatch repair proteins and MLH1 methylation were assessed to classify tumors as sporadic or probable Lynch syndrome (PLS). In this cohort, 10.5% of patients were designated as PLS based on tumor testing. The sensitivity and specificity of the SGO criteria to identify these same cases were 32.6% [95% confidence interval (CI), 19.2-48.5] and 77% (95% CI, 72.7-81.8), respectively. With the exception of tumor location in the lower uterine segment, multivariate analysis of clinical features, family history, and pathologic variables failed to identify significant differences between the sporadic and PLS groups. A simplified cost-effectiveness analysis demonstrated that the SGO clinical criteria and universal tissue testing strategies had comparable costs per patient with PLS identified. In conclusion, the SGO criteria successfully identify PLS cases among women with endometrial cancer who are young or have significant family history of signature tumors. However, a larger proportion of patients with PLS who are older and have less significant family history are not detected by this screening strategy. Universal tissue testing may be necessary to capture more individuals at risk for having Lynch syndrome.

Overweight, obesity and endometrial cancer risk: results from a systematic review and meta-analysis

AIM

Findings from recent studies suggest that obesity may be associated with an increased risk of endometrial cancer, but several earlier studies were less conclusive. Here we strive to estimate this relationship in a meta-analysis of published data.

METHODS

We searched Pubmed and Embase for studies on body mass index and the risk of endometrial cancer, published from 1989 to 2011. Data were independently extracted and analyzed using random or fixed effects meta-analysis depending on the degree of heterogeneity.

RESULTS

Seven cohort studies and 11 case-control studies were included in the meta-analysis. Overall, the conditions of excess body weight ([EBW] defined as body mass index [BMI] ≥25 kg/m²), obesity (BMI ≥30 kg/m²) and overweight (25< BMI <30 kg/m²) were associated with an increased risk of endometrial cancer (relative risk [RR] for EBW=1.62, 95% confidence interval [CI], 1.39-1.89; for obesity RR=2.54, 95% CI, 2.11-3.06; for overweight RR=1.32, 95% CI, 1.16-1.50). Subgroup analyses showed that the positive associations were independent of study design, geographic locations, self-reported BMI, alcohol use, smoking habit, history of diabetes, hormone therapy, age at menarche, age at menopause, parity, and age at first full term pregnancy. However, there was no statistically significant association between EBW and endometrial cancer risk for measured BMI (for EBW RR=1.29, 95% CI, 0.66-2.53).

CONCLUSIONS

The findings from this meta-analysis strongly support that the conditions of EBW, overweight, and obesity are all associated with an increased risk of endometrial cancer. Also, the strength of the association increases with increasing BMI.

Endometrial Carcinoma in Women Aged 40 Years and Younger

Context.—Endometrial carcinoma is a disease of older postmenopausal women, and is relatively uncommon in patients younger than 40 years. Endometrial carcinomas in this age group may be familial, associated with Lynch syndrome, or sporadic.

Objectives.—To present our current knowledge of endometrial carcinomas in women younger than 40 years.

Data Sources.—The review is based on previously published articles on this topic.

Conclusions.—Most endometrial carcinomas that occur in this age group are associated with estrogen excess. They are usually low-grade endometrioid carcinomas that present at low stages and are associated with favorable clinical outcomes. Tumors associated with mismatch repair abnormalities and Lynch syndrome appear to be distinct, with worse prognostic factors and, possibly, clinical behavior. Conservative hormonal therapy and ovarian conservation are reasonable considerations in the management of these young patients, but carry the risk of tumor progression, recurrence, and an occult synchronous or metachronous ovarian carcinoma.

Mismatch repair protein expression in 1049 endometrial carcinomas, associations with body mass index, and other clinicopathologic variables

OBJECTIVE

Links between obesity, with its attendant estrogen abnormalities, and the endometrial carcinoma (EC) DNA Mismatch Repair Protein (MMR) system have recently been proposed. We investigated relationships between body mass index (BMI) and clinicopathological correlates including MMR expression in a large single institution EC cohort.

METHODS

Clinical and pathological databases from 2007 to 2012 were used to identify consecutive hysterectomy specimens with EC. Univariate and multivariate analyses were used to explore relationships between BMI, age, stage, tumor type and immunohistochemical results for MLH1, PMS2, MSH2 and MSH6.

RESULTS

1049 EC were identified. Overall, BMI was higher amongst women with normal MMR (p=0.002). However, when stratified by age and specific MMR, statistically significant differences localized exclusively to women <50years old with loss of MSH2 and/or MSH6 (p=0.003 and p=0.005 respectively). Higher BMI correlated with endometrioid FIGO 1 and 2 tumors (p<0.001) and with stage 1a (p<0.001). Conversely, MMR abnormalities did not show significant associations with stage (p=0.302) or histologic grade (p=0.097).

CONCLUSIONS

BMI showed statistically significant associations with MMR expression, tumor grade and stage amongst 1049 consecutive EC. Obesity correlates with lower grade and stage EC. A link between BMI and maintenance of the MMR system is not supported by our data because the only statistically significant association occurred in women <50years old with MSH2 and/or MSH6 abnormalities where Lynch syndrome related cases are expected to cluster.

Anthropometric measures and the risk of endometrial cancer, overall and by tumor microsatellite status and histological subtype

Obesity is an established risk factor for endometrial cancer, but this association is not well understood for subtypes of endometrial cancer. We evaluated the association of recent and adult-life obesity with subtypes of endometrial cancer based on microsatellite status (microsatellite-stable (MSS) vs. microsatellite-instable (MSI)) and histology (type I vs. type II). Analyses were based on a population-based case-control study (524 cases and 1,032 controls) conducted in Alberta, Canada (2002-2006) and included the following groupings of subtypes: MSS = 337 and MSI = 130; type I = 458 and type II = 66. Logistic and polytomous logistic regression were used to estimate odds ratios and 95% confidence intervals for overall endometrial cancer and subtypes of endometrial cancer, respectively. The risks of all subtypes of endometrial cancer, except type II, increased with an increase in all of the anthropometric characteristics examined. The risks for MSI tumors were suggestively stronger than those for MSS tumors; the risk with high (≥30) body mass index (weight (kg)/height (m)(2)) was significantly stronger for MSI tumors (odds ratio = 4.96, 95% confidence interval: 2.76, 8.91) than for MSS tumors (odds ratio = 2.33, 95% confidence interval: 1.66, 3.28) (P-heterogeneity = 0.02). Obesity is associated with most subtypes of endometrial cancer, and further studies are warranted to elucidate the biological mechanisms underlying the stronger risk for the MSI subtype with a high body mass index.

Hormonal and reproductive risk factors for sporadic microsatellite stable and unstable endometrial tumors

Hormonal and reproductive factors modulate bioavailable estrogen to influence endometrial cancer risk. Estrogen affects the microsatellite status of tumors, but the relation between these estrogen-related factors and microsatellite instability (MSI) status of endometrial tumors is not known. We evaluated associations between hormonal and reproductive factors and risks of microsatellite stable (MSS) and MSI endometrial cancer among postmenopausal women (MSS cases = 258, MSI cases = 103, and controls = 742) in a population-based case-control study in Alberta, Canada (2002-2006). Polytomous logistic regression was used to estimate ORs and 95% confidence intervals (95% CI). We observed a significant trend in risk reduction for MSI (Ptrend = 0.005) but not MSS (Ptrend = 0.23) cancer with oral contraceptive use; with 5-year use or more, the risk reduction was stronger for MSI (OR = 0.42; 95% CI, 0.23-0.77) than for MSS cancer (OR = 0.80; 95% CI, 0.54-1.17; Pheterogeneity = 0.05). For more recent use (<30 years), the risk reduction was stronger for MSI (OR = 0.36; 95% CI, 0.19-0.69) than for MSS cancer (OR = 0.77; 95% CI, 0.51-1.15; Pheterogeneity = 0.032). No differential risk associations were observed for menopausal hormone use, parity and age at menarche, menopause or first pregnancy. We found limited evidence for statistical heterogeneity of associations of endometrial cancer risk with hormonal and reproductive factors by MSI status, except with oral contraceptive use. This finding suggests a potential role for the MMR system in the reduction of endometrial cancer risk associated with oral contraceptive use, although the exact mechanism is unclear. This study shows for the first time that oral contraceptive use is associated with a reduced risk for MSI but not for MSS endometrial cancer.

Histologic evaluation of prophylactic hysterectomy and oophorectomy in Lynch syndrome

Women with Lynch syndrome (LS) are at increased risk for endometrial (EC) and ovarian carcinoma (OC). Current surveillance recommendations for detection of EC and OC in LS patients are not effective. Small studies have shown that prophylactic hysterectomy and bilateral salpingo-oophorectomy (P-TH-BSO) are the most effective and least expensive preventive measures in these patients. Data regarding histologic findings in prophylactic specimens in these patients are lacking. All LS patients who underwent P-TH-BSO at the Memorial Sloan-Kettering Cancer Center from 2000 to 2011 were identified. Slides were evaluated for the presence of endometrial hyperplasia (EH), EC, OC, or any other recurrent histologic findings. Twenty-five patients were identified, with an age range of 36 to 61 years. Fifteen patients had a synchronous or prior colorectal carcinoma, and 2 patients had a history of sebaceous carcinoma. Focal FIGO grade 1 endometrioid ECs were detected in 2 patients; 1 was 54 years of age (MSH2 mutation; superficially invasive), and the other was 56 years of age (MLH1 mutation; noninvasive). Focal complex atypical hyperplasia, unassociated with carcinoma, was seen in 3 patients, ages 35 and 45 (MLH1 mutations) and 53 years (MSH2 mutation). One patient (44 y, with MSH2 mutation) was found to have a mixed endometrioid/clear cell OC and simple EH without atypia. The OC was adherent to the colon but did not show distant metastasis. In our study, P-TH-BSOs performed because of the presence of LS revealed incidental EC and/or EH in 24% of cases and OC in 4%. The ECs were low grade, confined to the endometrium, and seen in patients older than 50 years. Prophylactic hysterectomy allows detection of early lesions in LS; these lesions appear to be small and focal. This small series of prophylactic hysterectomies may provide some clues about LS-associated endometrial carcinogenesis.

Influence of body mass index on clinicopathologic features, surgical morbidity and outcome in patients with endometrial cancer

AIM

To examine the influence of obesity on the patient characteristics and clinicopathologic features of endometrial cancer, and to find how treatment and prognosis were affected by obesity in women with endometrial cancer.

METHODS

The data of 370 consecutive women operated for endometrial cancer were retrospectively reviewed. Patients were divided into three categories as <25, 25-29.9 and ≥30 according to BMI. All patients underwent primary surgical treatment including total abdominal hysterectomy, bilateral oophorectomy and peritoneal cytology. Pelvic lymphadenectomy was carried out for all patients except for those with no myometrial invasion regardless of the tumor grade or for whom it was technically impossible. Paraaortic lymphadenectomy was performed when pre- and intraoperative assessments suggested non-endometrioid or grade 3 endometrioid cancer, >50 % myometrial invasion and cervical involvement.

RESULTS

Patients with a BMI (body mass index) of <25 were significantly younger. Patients with a BMI of ≥30 were statistically less likely to have >50 % myometrial invasion and more likely to have stage I disease. There were no significant differences in the incidences of positive pelvic and paraaortic lymph nodes and tumor grades between the three groups. Also, there were no differences in surgery type, the mean of removed pelvic and paraaortic lymph node number, hospital stay, blood loss and complications between the groups. The patients with a BMI of ≥30 had significantly longer operating time. There were no statistically significant differences in recurrences, the median number of months at recurrence or the site of recurrence between the three groups, as well as the 5-year overall and disease-free survival of patients. Multivariate proportional hazard models identified stage III and IV disease as significant covariates for mortality rates, while stage III and IV disease, hypertension and pelvic irradiation were identified as significant covariates for recurrence rates.

CONCLUSION

Positive peritoneal cytology, deep myometrial invasion and stage II-IV endometrial cancer were significantly more common in patients with a BMI of <25. There were no significant differences in tumor grade, surgical technique, surgical morbidity or adjuvant radiotherapy between the BMI groups. Recurrence and cancer-related mortality rates were not affected by the BMI.

Honey and cancer: sustainable inverse relationship particularly for developing nations-a review

Honey and cancer has a sustainable inverse relationship. Carcinogenesis is a multistep process and has multifactorial causes. Among these are low immune status, chronic infection, chronic inflammation, chronic non healing ulcers, obesity, and so forth. There is now a sizeable evidence that honey is a natural immune booster, natural anti-inflammatory agent, natural antimicrobial agent, natural cancer "vaccine," and natural promoter for healing chronic ulcers and wounds. Though honey has substances of which the most predominant is a mixture of sugars, which itself is thought to be carcinogenic, it is understandable that its beneficial effect as anticancer agent raises skeptics. The positive scientific evidence for anticancer properties of honey is growing. The mechanism on how honey has anticancer effect is an area of great interest. Among the mechanisms suggested are inhibition of cell proliferation, induction of apoptosis, and cell-cycle arrest. Honey and cancer has sustainable inverse relationship in the setting of developing nations where resources for cancer prevention and treatment are limited.

Body weight changes after the diagnosis of endometrial cancer and their influences on disease-related prognosis

OBJECTIVES

Obesity is associated with the incidence of endometrial cancer. At present it is unclear whether it is also associated with cancer recurrence. This analysis evaluated the consequences of weight changes after diagnosis of endometrial cancer during the follow-up.

METHODS

Records of patients with endometrial cancer (n = 705) were reviewed for body weight after the diagnosis of cancer during the follow-up and related to recurrence-free survival.

RESULTS

About two-thirds of all endometrial patients gained more or less weight after the diagnosis of endometrial cancer. Patients with moderate weight gain (≤ 1 kg/m(2)) 6 months after the diagnosis had the best prognosis, followed by patients with greater weight gain (>1 kg/m(2)) and those with moderate weight loss (≤ 1 kg/m(2)). The fact that weight loss was associated with poor prognosis also persisted when the analysis was restricted to recurrences which occurred more than 18 months later.

CONCLUSIONS

Weight loss after the diagnosis and treatment of cancer may be an adverse prognostic factor. Although it was impossible to distinguish between intentional and non-intentional weight loss, these results argue against weight loss for risk reduction in patients with confirmed endometrial cancer. However, it may be reasonable regarding the risk reduction of non-cancer related morbidity and mortality. Detailed, prospective randomised trials are warranted.

Body mass and DNA promoter methylation in breast tumors in the Western New York Exposures and Breast Cancer Study

BACKGROUND

The mechanism of the observed association between body mass, particularly centralized body fat, and postmenopausal breast cancer risk is not well understood.

OBJECTIVE

We hypothesized that body mass may affect DNA methylation through increased estrogen and chronic inflammation. The association between body mass and promoter methylation in breast tumors was investigated in a population-based, case-control study.

DESIGN

The promoter methylation of E-cadherin, p16, and RAR-β(2) genes was assessed in breast tumor blocks from 803 pre- and postmenopausal cases by using real-time methylation-specific polymerase chain reaction. Unconditional logistic regression was used to derive the adjusted OR and 95% CI for case-case comparisons of tumors with and without promoter methylation of the genes.

RESULTS

The frequency of promoter methylation was 20% for E-cadherin, 25.9% for p16, and 27.5% for RAR-β(2). There was no difference in the prevalence of the DNA methylation of individual genes by BMI, waist-to-hip ratio (WHR), or lifetime weight change between the age of 20 y and the present. However, in a case-case comparison of postmenopausal breast cancer, a greater WHR was associated with an increased likelihood of ≥1 of the 3 genes being methylated (OR: 1.85; 95% CI: 1.10, 3.11; P-trend < 0.02).

CONCLUSIONS

We showed that WHR was associated with DNA promoter methylation of ≥1 of 3 genes in postmenopausal breast tumors. It may be that the association of body fat composition and postmenopausal breast cancer is related to altered DNA methylation. However, future studies in other populations and with an examination of the methylation of more genes are needed.

Body mass index in early adulthood and endometrial cancer risk for mismatch repair gene mutation carriers

OBJECTIVE

To investigate the association of body mass index (BMI) in early adulthood and endometrial cancer risk for carriers of a germline mutation in a DNA mismatch repair gene.

METHODS

We estimated the association between BMI at age 18-20 years and endometrial cancer risk for mismatch repair gene mutation carriers and, as a comparison group, noncarriers using 601 female carriers of a germline mutation in a mismatch repair gene (245 MLH1, 299 MSH2, 38 MSH6, and 19 PMS2) and 533 female noncarriers from the Colon Cancer Family Registry using a weighted Cox proportional hazards regression.

RESULTS

During 51,693 person-years of observation, we observed diagnoses of endometrial cancer for 126 carriers and eight noncarriers. For carriers, there was no evidence of an association between BMI at age 20 years and endometrial cancer (adjusted hazard ratio 0.73 per 5 kg/m²; 95% confidence interval [CI], 0.40-1.34; P=.31). For noncarriers, endometrial cancer risk increased by 74% for each 5-kg/m² increment in BMI (adjusted hazard ratio 1.74; 95% CI 1.27-2.37; P<.001). The hazard ratio for BMI and endometrial cancer for noncarriers was greater than for carriers (P=.04).

CONCLUSION

The effect of body mass on endometrial cancer risk depends on the woman's mismatch repair gene mutation carrier status, suggesting obesity-independent endometrial carcinogenesis for carriers.

LEVEL OF EVIDENCE

II.

Familial Tumors of the Uterine Corpus

Women with Lynch syndrome are at considerable risk for developing endometrial carcinoma, but current screening guidelines for detection of Lynch syndrome focus almost exclusively on colorectal carcinoma. Lynch syndrome associated colorectal and endometrial carcinomas have some important differences with implications for screening strategies. These differences are discussed in this review, along with the most effective screening criteria and testing methods for detection of Lynch syndrome in endometrial carcinoma patients.

Modern approach to metabolic rehabilitation of cancer patients: biguanides (phenformin and metformin) and beyond

Comparing the experience accumulated for more than 40 years in the Laboratory of Endocrinology of Petrov Institute of Oncology (St Petersburg, Russia) with similar approaches practiced elsewhere, evidence supports the reasonability of metabolic rehabilitation of patients suffering from breast cancer or other hormone-dependent malignancies. The primary objective of such approaches is to improve treatment results by ameliorating hormonal-metabolic disturbances, including excess body fat, glucose intolerance, insulin resistance and manifestations of endocrine-genotoxic switchings, and modify tissue and cellular targets or mechanisms related or nondirectly related to the aforementioned disturbances. The relevant measures may be categorized as pharmacological (antidiabetic biguanides exemplified with metformin being most popular but not exclusive) and nonpharmacological (rational nutrition, moderate physical activity and so forth) and used separately or in different combinations.

The effect of modifiable potentials on hypermethylation status of retinoic acid receptor-beta2 and estrogen receptor-alpha genes in primary breast cancer

Epigenetic silencing of retinoic acid receptor-beta2 (RARbeta2) and estrogen receptor-alpha (ERalpha) expressions have been revealed to be important in the development of approaches for diagnosis and therapy of breast cancer. We aimed to explore the correlation of some potential factors with the hypermethylation status of RARbeta2 and ERalpha genes among Iranian breast cancer patients. The hypermethylation status was investigated in 137 dissected tissues from primary breast cancer patients through methylation-specific PCR. Overall, the methylation frequencies of RARbeta2 and ERalpha genes were observed in 36.5 and 51.1% of participants, respectively. The hypermethylated RARbeta2 was associated with younger age at diagnosis and negative family history of breast cancer. The hypermethylation of ERalpha was correlated positively with smoking, duration of estradiol exposure, ER-negativity in tumors and body mass index (at 5 years ago). The plasma levels of folate and vitamin B(12) were inversely related to the hypermethylation status of ERalpha, after controlling for covariates. The risk of ERalpha hypermethylation was increased with high plasma level of total homocysteine. In conclusion, our data provide new insights into the possible effect of some lifestyle-related factors on the aberrant methylation drift of ERalpha and RARbeta2 genes in breast cancer.

Obesity is an independent prognostic variable in colon cancer survivors

PURPOSE

Obesity is associated with an increased risk of colon cancer. However, the influence of body mass index (BMI) on the prognosis of colon cancer survivors and its relationship to gender remains unknown.

EXPERIMENTAL DESIGN

BMI (kg/m(2)) was categorized in patients with tumor-node-metastasis stage II and III colon carcinomas (n = 4,381) enrolled in seven randomized trials of 5-fluorouracil-based adjuvant chemotherapy. Cox proportional hazards models were used to determine the association of BMI with disease-free survival (DFS) and overall survival (OS).

RESULTS

Among colon cancer patients, 868 (20%) were obese (BMI, >or=30 kg/m(2)), of which 606 were class 1 (BMI, 30-34 kg/m(2)) and 262 were class 2,3 (BMI, >or=35 kg/m(2)). Obese versus normal-weight patients were more likely to be younger, have distal tumors, show intact DNA mismatch repair, and have more lymph node metastases (P < 0.017). In a multivariate analysis, BMI was significantly associated with both DFS (P = 0.030) and OS (P = 0.0017). Men with class 2,3 obesity showed reduced OS compared with normal-weight men [hazard ratio, 1.35; 95% confidence interval, 1.02-1.79; P = 0.039]. Women with class I obesity had reduced OS [hazard ratio, 1.24; 95% confidence interval, 1.01-1.53; P = 0.045] compared with normal-weight women. Overweight status was associated with improved OS in men (P = 0.006), and underweight women had significantly worse OS (P = 0.019). BMI was not predictive of therapeutic benefit.

CONCLUSIONS

Obesity is an independent prognostic variable in colon cancer survivors and shows gender-related differences. These data suggest that obesity-related biological factors can influence clinical outcome.

Metabolic syndrome and cancer

Since its first description by Reavan in 1988, accepted criteria for clinical identification of the components of metabolic syndrome have been promulgated by the National Cholesterol Education Program/Adult Treatment Panel III (NCEP/ATP III) and the World Health Organization (WHO) as well as the International Diabetes Federation (IDF), and the American Association of Clinical Endocrinologists (AACE). Insulin resistance is a common metabolic abnormality underlying type 2 diabetes mellitus and is also an independent risk factor for cardiovascular disease. Although ATP III identified cardiovascular disease (CVD) as the primary clinical outcome of the metabolic syndrome, we now have evidence that metabolic syndrome is associated with type 2 diabetes mellitus, polycystic ovarian disease, nonalcoholic fatty liver disease, and possibly some cancers. This review summarizes evidence in support of the relationship between metabolic syndrome and various cancers and possible underlying mechanisms and therapeutic interventions.

DNA mismatch repair deficiency in endometrial carcinoma

Microsatellite instability (MSI) is the hallmark of a molecular pathway to carcinogenesis due to sporadic or inherited abnormalities of DNA mismatch repair genes. Inherited mutations are seen in hereditary nonpolyposis colorectal cancer syndrome. Endometrial carcinoma shows as high an incidence of MSI as does colorectal carcinoma. This review provides a framework for the gynecologic pathologist to understand the complexities of MSI in endometrial carcinoma, by discussing the basic mechanisms of mismatch repair and carcinogenesis, testing, the morphologic features of MSI endometrial cancer and the contradictory data regarding prognosis.

Clinicopathological features in endometrial carcinoma associated with Lynch syndrome in China

OBJECTIVE

To study the clinicopathological characteristics of Lynch syndrome-associated endometrial carcinoma in China.

METHODS

Twenty-seven patients who fulfilled Amsterdam criteria II were classified as having Lynch syndrome-associated endometrial carcinoma (group A), and 331 patients without a family history of cancer were classified as having sporadic endometrial carcinoma (group B).

RESULTS

There were 81 malignancies in 27 families with Lynch syndrome-associated endometrial carcinoma, including colorectal cancer (24.7%), endometrial carcinoma (21.0%), and liver (12.3%), stomach (9.9%), lung (6.2%), and breast (6.2%) cancers. Mean age at the time of diagnosis was 49.7 years in group A and 56.3 years in group B (P = 0.004). Second primary cancers occurred in 33.3% of patients in group A and 5.1% in group B (P = 0.000). The most common second primary cancers were colorectal cancer (44%) and ovarian cancer (22%). The percentage of obese patients was higher in group A (P= 0.013). There was no difference between the 2 groups in incidence of diabetes mellitus or hypertension or in histological type and International Federation of Gynecology and Obstetrics stage. The 5-year survival rates for groups A and B were 96.2% and 79.6%, respectively. Prognosis for group A was better than for group B (P = 0.045).

CONCLUSIONS

Some clinicopathological features of Lynch syndrome-associated endometrial carcinoma, such as early onset and multiple primary carcinomas are similar in the Chinese and American/European populations. However, the Chinese population had a unique family cancer distribution that included lung and breast cancers. Well-differentiated grade and good prognosis imply better biobehavior of Lynch syndrome-associated endometrial carcinoma in the Chinese population.

Enhanced estrogen-induced proliferation in obese rat endometrium

OBJECTIVE

We tested the hypothesis that the proliferative estrogen effect on the endometrium is enhanced in obese vs lean animals.

STUDY DESIGN

Using Zucker fa/fa obese rats and lean control, we examined endometrial cell proliferation and the expression patterns of certain estrogen-regulated proproliferative and antiproliferative genes after short-term treatment with estradiol.

RESULTS

No significant morphologic/histologic difference was seen between the obese rats and the lean rats. Estrogen-induced proproliferative genes cyclin A and c-Myc messenger RNA expression were significantly higher in the endometrium of obese rats compared with those of the lean control. Expression of the antiproliferative gene p27Kip1 was suppressed by estrogen treatment in both obese and lean rats; however, the decrease was more pronounced in obese rats. Estrogen more strongly induced the antiproliferative genes retinaldehyde dehydrogenases 2 and secreted frizzled-related protein 4 in lean rats but had little or no effect in obese rats.

CONCLUSION

Enhancement of estrogen-induced endometrial proproliferative gene expression and suppression of antiproliferative gene expression was seen in the endometrium of obese vs lean animals.

Increased prevalence of obesity and obesity-related postoperative complications in male patients with meningiomas

OBJECTIVE

The female preponderance of meningiomas may reflect hormonal influences on meningioma growth. We hypothesized that because obesity affects male steroid hormone synthesis, male patients with meningiomas might exhibit a high obesity rate, which, in turn, might increase their frequency of postoperative complications.

METHODS

We retrospectively reviewed male patients who underwent craniotomy for benign meningiomas at our institution between 2001 and 2005 (n = 32) and used male patients undergoing craniotomy for aneurysms (n = 32) or glioblastomas (n = 32) from 2001 to 2005 as control subjects. Body mass index (BMI) greater than 30 kg/m was considered obese.

RESULTS

Male patients with meningiomas had a higher average BMI (30.2 kg/m) than male patients with aneurysms (BMI = 27.5 kg/m) or gliomas (BMI = 25.9 kg/m) (P = 0.04). The obesity rate in men with meningiomas (47%) exceeded that in men with aneurysms (19%) or gliomas (3%) (P = 0.2). The median age-normalized BMI percentile was greater in men with meningiomas (67 th percentile) than in men with aneurysms (49th percentile) or gliomas (52 nd percentile) (P = 0.02). Deep vein thrombosis/pulmonary embolus was more common in men with meningiomas (19%) than in men with aneurysms (0%) or gliomas (3%) (P = 0.002). Wound infections were more common in men with meningiomas (6%) than in men with aneurysms (3%) or gliomas (0%) (P = 0.2). The 53% of obese patients with meningiomas who were readmitted with postoperative complications exceeded the 18% of nonobese patients with meningiomas who were readmitted (P = 0.03); complications included deep vein thrombosis and pulmonary embolus (27 and 12%, respectively, in obese and nonobese patients with meningiomas) and postoperative fever (53 and 35%, respectively, in obese and nonobese patients with meningiomas).

CONCLUSION

We found that many men with meningiomas are obese, suggesting a hormonal influence on meningiomas in men as well as women. Our results also underscore the high risk of postoperative complications in obese male patients with meningiomas.

Correlation between patient weight and defects in DNA mismatch repair: is this the link between an increased risk of previous cancer in thinner women with endometrial cancer?

The objective is to determine the relationship between obesity and defects in DNA mismatch repair (MMR) in women with endometrial cancer and to establish whether our previous finding of a higher rate of previous malignancy in thinner women with endometrial cancer is related to these factors. Specimens from 109 patients with primary uterine cancer were used to create a tissue microarray, which was stained with antibodies against MMR genes MLH1, MSH2, MSH6, and PMS2. Genotyping of normal and tumor tissues for microsatellite instability (MSI) was performed. Patients were stratified by body mass index (BMI) and correlated with a history of previous malignancy and defects in MMR. The average BMI of the overall population was 33 kg/m(2). Defective MMR was seen in 22% of tumors. The mean BMI in patients with tumors with MSI was 30.5, compared with 33.8 in microsatellite stable (MSS) tumors (P= 0.06); MSS tumors were more commonly seen in patients with a BMI more than 40 (25% vs 5% in patients with tumors with MSI, P= 0.07). Prior to their diagnosis of endometrial cancer, 16/109 (15%) patients reported having a prior malignancy, 11 (69%) had breast cancer, and 1 had colorectal cancer. Patients with tumors with MSI had previous cancer in 17% of cases, compared with 14% of patients with MSS tumors (P= 0.75). Our previous finding of an increased rate of prior malignancy in thinner patients with endometrial cancer does not appear to be due to alterations in MMR, and hereditary nonpolyposis colorectal cancer-associated cancers are rarely the prior malignancy.