Molecular analysis of endometrial tumorigenesis: importance of complex hyperplasia regardless of atypia

Diaphragmatic clear cell carcinoma with Lynch syndrome after surgery for atypical endometrial hyperplasia and ovarian endometriosis: A case report

Clear cell carcinoma (CCC) of the diaphragm is rare, with an origin that is reported to be associated with malignant transformation of extraperitoneal endometriosis. Lynch syndrome (LS) is an autosomal dominant hereditary cancer syndrome caused by germline pathogenic variants in one of the DNA mismatch repair (MMR) genes, MLH1, MSH2, MSH6 and PMS2. Women with LS have a significantly increased lifetime risk of endometrial and ovarian cancer. CCC is a common histology of endometriosis- and LS-associated malignancy. The present study describes the case of a 51-year-old woman with an intra-abdominal mass found during a routine physical examination. The patient had undergone total hysterectomy and bilateral adnexectomy for atypical endometrial hyperplasia (AEH) and ovarian endometriosis, respectively, 3 years previously. Enhanced computed tomography showed a mass on the surface of the liver. Laparoscopic examination of the abdominal cavity revealed a tumor on the underside of the right diaphragm, which was then surgically excised. Pathological examination of the excised tumor, along with immunohistochemistry, led to a diagnosis of CCC. Since LS was suspected due to the genetic family history of the patient, microsatellite instability analysis was performed on the diaphragmatic tumor, and the results were positive. Immunohistochemistry was performed for MMR proteins in AEH and CCC cells, both of which revealed loss of MSH2 and MSH6 expression. Following detailed genetic counseling, genetic testing of MMR genes was performed, revealing a germline pathogenic variant in MSH2 (c.1000C>T, p.Gln344*), thus confirming the diagnosis of LS. To the best of our knowledge, this is the first case report of concurrent diaphragmatic CCC and LS. Patients with LS and endometriosis are at risk of developing ovarian cancer or intra-abdominal malignant tumors. In addition, immunohistochemistry screening for MMR proteins should be considered in patients with AEH and a family history of LS-related cancer, to enable early clinical intervention in cases of endometrial cancer.

DNA methylation of selected tumor suppressor genes in endometrial hyperplasia

AIMS

To investigate DNA methylation of specific gene promoters in endometrial hyperplasia compared to normal endometrial tissue.

MATERIALS AND METHODS

To search for epigenetic events, methylation-specific multiplex ligation-dependent probe amplification was employed to compare the methylation status of 64 tissue samples with atypical endometrial hyperplasia, 60 tissue samples with endometrial hyperplasia without atypia, and 40 control tissue samples with normal endometrium.

RESULTS

Differences in DNA methylation among the groups were found in PTEN, CDH13, and MSH6 promoters (PTEN: atypical hyperplasia 32%, benign hyperplasia 6.8%, normal endometrium 10%; P=0.004; CDH13: atypical hyperplasia, 50%; benign hyperplasia, 43%; normal endometrium 8.1%; P=0.003; MSH6 atypical hyperplasia 84%, benign hyperplasia, 62%; normal endometrium, 52%; P=0.008.) Higher rates of CDH13 promoter methylation were identified in the groups with both forms of endometrial hyperplasia when compared to the control group (atypical hyperplasia, P=0.003, benign hyperplasia, P=0.0002). A higher rate of DNA methylation of the PTEN and MSH6 promoters was observed in samples with atypical endometrial hyperplasia than in samples with benign endometrial hyperplasia (PTEN: P=0.02; MSH6: P=0.01) and samples with normal endometrial tissue (PTEN, P=0.04; MSH6, P=0.006).

CONCLUSION

DNA methylation of CDH13, PTEN, and MSH6 appear to be involved in the development of endometrial hyperplasia.

Epigallocatechin Gallate for the Treatment of Benign and Malignant Gynecological Diseases-Focus on Epigenetic Mechanisms

The most common malignant gynecologic diseases are cervical, uterine, ovarian, vaginal, and vulvar cancer. Among them, ovarian cancer causes more deaths than any other cancer of the female reproductive system. A great number of women suffer from endometriosis, uterine fibroids (UFs), adenomyosis, dysmenorrhea, and polycystic ovary syndrome (PCOS), which are widespread benign health problems causing troublesome and painful symptoms and significantly impairing the quality of life of affected women, and they are some of the main causes of infertility. In addition to the available surgical and pharmacological options, the effects of supporting standard treatment with naturally occurring compounds, mainly polyphenols, are being studied. Catechins are responsible for the majority of potential health benefits attributed to green tea consumption. Epigallocatechin gallate (EGCG) is considered a non-toxic, natural compound with potential anticancer properties. Antioxidant action is its most common function, but attention is also drawn to its participation in cell division inhibition, apoptosis stimulation and epigenetic regulation. In this narrative review, we describe the role of EGCG consumption in preventing the development of benign reproductive disorders such as UF, endometriosis, and PCOS, as well as malignant gynecologic conditions. We discuss possible epigenetic mechanisms that may be related to the action of EGCG.

Highly Sensitive Microsatellite Instability and Immunohistochemistry Assessment in Endometrial Aspirates as a Tool for Cancer Risk Individualization in Lynch Syndrome

Women with Lynch syndrome (LS) are at increased risk of endometrial cancer (EC), among other tumors, and are characterized by mismatch repair (MMR) deficiency and microsatellite instability (MSI). While risk-reducing gynecological surgeries are effective in decreasing EC incidence, doubts arise regarding the appropriate timing of the surgery. We explored the usefulness of highly-sensitive MSI (hs-MSI) assessment in endometrial aspirates for the individualization of gynecological surveillance in LS carriers. Ninety-three women with LS, 25 sporadic EC patients (9 MMR-proficient and 16 MMR-deficient), and 30 women with benign gynecological disease were included in this study. Hs-MSI was assessed in prospectively collected endometrial aspirates in 67 LS carriers, EC cases, and controls. MMR, PTEN, ARID1A, and PAX2 expression patterns were evaluated in LS samples. Follow-up aspirates from eight LS carriers were also analyzed. Elevated hs-MSI scores were detected in all aspirates from MMR-deficient EC cases (3 LS and 16 sporadic), being negative in aspirates from controls and MMR-proficient EC cases. Positive hs-MSI scores were also detected in all four LS aspirates reported as complex hyperplasia. High hs-MSI was also present in 10 of 49 aspirates (20%) from LS carriers presenting a morphologically normal endometrium, where MMR expression loss was detected in 69% of the samples. Interestingly, the hs-MSI score was positively correlated with MMR-deficient gland density and the presence of MMR-deficient clusters, colocalizing with PTEN and ARID1A expression loss. High hs-MSI scores and clonality were evidenced in two samples collected up to four months before EC diagnosis; hs-MSI scores increased over time in five LS carriers, whereas they decreased in a patient with endometrial hyperplasia after progestin therapy. In LS carriers, elevated hs-MSI scores were detected in aspirates from premalignant and malignant lesions and normal endometrium, correlating with MMR protein loss. Hs-MSI assessment and MMR immunohistochemistry may help individualize EC risk assessment in women with LS.

Analysis of endometrial carcinoma TCGA reveals differences in DNA methylation in tumors from Black and White women

OBJECTIVE

Racial disparities exist in cancer patients both in incidence and death rates. In endometrial cancer, Black patients are reported to have higher incidence of aggressive endometrial cancer subtypes and higher death rates than White women. To date, diagnostic and prognostic biomarkers associated with race-specific methylation driven genes have yet to be identified. The objective of this study was to explore DNA methylation patterns in endometrial tumor samples from White and Black women.

METHODS

Differentially methylated CpGs (DMCs) and differentially methylated regions (DMRs) were identified in White tumor samples compared to Black tumor samples using Endometrial Carcinoma (EC) methylation and clinical data from The Cancer Genome Atlas (TCGA). Survival analysis was performed using survival R package and results were visualized using Kaplan-Meier plots. To access the correlation between changes in methylation and gene expression, we downloaded raw RNA-sequencing by Expectation-Maximization (RSEM) counts data from The Cancer Genome Atlas (TCGA) using TCGABiolinks package (v2.18.0).

RESULTS

Our analysis revealed 704 differentially methylated CpGs in tumors from Black and White women. These differentially methylated genes showed strong negative correlation with gene expression and statistically significant enrichment in regulatory regions such as DNase I hypersensitivity sites (DHSs) and transcription factor binding sites (TFBSs). Increased variability in methylation occurred in genes such as the insulin signaling pathway in Black tumor samples.

CONCLUSION

By using two independent statistical method based on means (DMR, DMCs) and variances (DVCs) on the endometrial carcinoma TCGA data, we showed that endometrial tumors from Black women are hypomethylated and more hypervariable than tumors from White women. In-depth investigation of these methylation driven markers can aid in successful management of endometrial cancer disparities and improved overall survival in Black and White populations.

Research Progress of DNA Methylation in Endometrial Cancer

Endometrial cancer (EC)) is one of the most common malignant tumors of the female genital system, with an increasing incidence and mortality, worldwide. Although the therapeutic strategy of EC is still complicated and challenging, further understanding of carcinogenesis from a gene perspective would allow an effort to improve therapeutic precision in this complex malignancy. DNA methylation is the most widely studied epigenetic alteration in human tumors. Aberrant DNA methylation events, resulting in altered gene expression, are features of many tumor types. In this review, we provide an update on evidence about the roles of aberrant DNA methylation within some classical tumor suppressor genes and oncogenes in endometrial carcinogenesis, and report on recent advances in the understanding of the contribution of aberrant DNA methylation to EC, as well as opportunities and challenges of DNA methylation in EC management and prevention.

Screening and risk reducing surgery for endometrial or ovarian cancers in Lynch syndrome: a systematic review

Objective

Lynch syndrome is a hereditary cancer syndrome caused by mismatch repair gene mutations, and female carriers are at an increased risk of endometrial and ovarian cancer. The best approach to screening is not yet clear and practice varies across countries and centers. We aimed to provide evidence to inform the best approach to screening and risk reduction.

Methods

A systematic search of the literature was conducted (Medline, Embase, PubMed). Studies evaluating the following were included: women with Lynch syndrome (by mismatch repair mutation or Amsterdam II criteria), screening methods for endometrial and/or ovarian cancer, intervention included endometrial biopsy, transvaginal ultrasound, or serum cancer antigen 125 (CA-125), outcomes evaluated were number of cancers and/or endometrial hyperplasia.

Results

A total of 18 studies of Lynch syndrome carriers which screened for endometrial cancer using transvaginal ultrasound and/or hysteroscopy/endometrial biopsy revealed an incidence of 3.9% at the time of screening. Most (64.1%) endometrial cancers detected were from screening, with the balance detected in symptomatic women at the first screening visits, regular review, or between screening intervals. In mismatch repair carriers, the overall sensitivity of endometrial screening was 66.7%, and the number needed to screen ranged between 4 and 38 (median 7). The sensitivity of endometrial biopsy was 57.1% and the number needed to screen was 23–380 (median 78). The sensitivity of transvaginal ultrasound was 34.4% and the number needed to screen was 35–973 (median 170). Fourteen studies which screened for ovarian cancer using transvaginal ultrasound and/or CA-125 revealed an incidence of 1.3% at the time of screening and 42.9% of ovarian cancers were detected at asymptomatic screening. The sensitivity of ovarian screening was 54.6%, and the number needed to screen was 9–191 (median 23) in mismatch repair carriers. Thirteen studies reported 5.8% incident endometrial cancers and 0.5% ovarian cancers at time of risk reducing surgery.

Conclusions

There is limited evidence to support screening for endometrial and ovarian cancer in Lynch syndrome and data on mortality reduction are not available. Further prospective, randomized trials comparing targeted screening methods are needed. Risk reducing surgery remains the most reliable way to reduce endometrial and ovarian cancer risk in Lynch syndrome.

DNA mismatch repair-deficient non-neoplastic endometrial glands are common in Lynch syndrome patients and are present at a higher density than in the colon

AIMS

The hallmark of Lynch syndrome (LS) is DNA mismatch repair protein (MMR) deficiency. Recently, MMR deficiency in non-neoplastic colonic crypts has been identified as a novel indicator of LS. We aimed to determine whether MMR-deficient non-neoplastic endometrial glands can distinguish patients with and without LS, and to compare the level of MMR deficiency in the normal endometrium and colon in LS patients.

METHODS AND RESULTS

We evaluated the immunohistochemical expression of MMR proteins in the normal endometrial mucosa from 64 patients, including 34 patients with confirmed LS (17 with endometrial cancer and 17 without cancer), 30 patients with endometrial cancer without LS (10 with tumours with MLH1 promoter hypermethylation and 20 with MMR-proficient tumours), and in the normal colonic mucosa from 30 LS patients. MMR-deficient non-neoplastic endometrial glands were identified in 47% of LS patients and in no patients without LS (P < 0.001). MMR-deficient non-neoplastic glands were more often identified in LS patients with endometrial cancer (65%) than in those without endometrial cancer (29%) (P = 0.04). In contrast to what was seen in the normal colon, MMR-deficient glands in the normal endometrium were seen as large, contiguous groups, ranging in number from two to 101 (87% versus 45%, P = 0.02). MMR-deficient glands were identified at a higher density in the endometrium than in the colon in LS patients (median number of MMR-deficient glands, 22 versus two, P = 0.02).

CONCLUSIONS

Our findings indicate that MMR-deficient non-neoplastic endometrial glands constitute an indicator of LS, and that MMR-deficient glands in the endometrium are present in a pattern of contiguous large groups.

Gynecological Surveillance and Surgery Outcomes in Dutch Lynch Syndrome Carriers

Simple Summary

Female Lynch syndrome (LS) carriers have an increased risk to develop endometrial and ovarian cancer. In the Netherlands, carriers are therefore advised annual gynecological surveillance and eventually, risk-reducing surgery. Global gynecological LS surveillance guidelines are scarce and based on limited evidence. These are, however, warranted to offer accurate surveillance. To provide more insight into surveillance outcomes, this study assessed outcomes of gynecological surveillance and risk-reducing surgery in 164 LS carriers diagnosed in our center, with a median follow-up of 5.6 years per carrier. Although most surveillance visits happened within an advised timeframe, we observed large variability in how gynecological surveillance visits were performed. This finding stresses the need for development of clear and evidence-based guidelines. Endometrial cancers identified at surveillance were all found in early stage, mostly symptomatic, questioning surveillance benefit. Large, prospective studies should assess to what extent current LS surveillance programs contribute to early detection of gynecological tumors.

Abstract

Lynch syndrome (LS) is caused by pathogenic germline variants in DNA mismatch repair (MMR) genes, predisposing female carriers for endometrial cancer (EC) and ovarian cancer (OC). Since gynecological LS surveillance guidelines are based on little evidence, we assessed its outcomes. Data regarding gynecological tumors, surveillance, and (risk-reducing) surgery were collected from female LS carriers diagnosed in our center since 1993. Of 505 female carriers, 104 had a gynecological malignancy prior to genetic LS diagnosis. Of 264 carriers eligible for gynecological management, 164 carriers gave informed consent and had available surveillance data: 38 MLH1, 25 MSH2, 82 MSH6, and 19 PMS2 carriers (median follow-up 5.6 years). Surveillance intervals were within advised time in >80%. Transvaginal ultrasound, endometrial sampling, and CA125 measurements were performed in 76.8%, 35.9%, and 40.6%, respectively. Four symptomatic ECs, one symptomatic OC, and one asymptomatic EC were diagnosed. Endometrial hyperplasia was found in eight carriers, of whom three were symptomatic. Risk-reducing surgery was performed in 73 (45.5%) carriers (median age 51 years), revealing two asymptomatic ECs. All ECs were diagnosed in FIGO I. Gynecological management in LS carriers varied largely, stressing the need for uniform, evidence-based guidelines. Most ECs presented early and symptomatically, questioning the surveillance benefit in its current form.

Frequent loss of mutation-specific mismatch repair protein expression in nonneoplastic endometrium of Lynch syndrome patients

Lynch syndrome is most often caused by a germline mutation in one of four DNA mismatch repair (MMR) genes (MLH1, PMS2, MSH2, or MSH6) or EPCAM and is associated with a significantly increased risk of endometrial cancer in affected women. Although universal screening of endometrial cancer for Lynch syndrome is becoming increasingly common by various algorithms using MMR immunohistochemistry and/or microsatellite instability testing by PCR, establishing the diagnosis of Lynch syndrome can be still challenging. MMR-deficient nonneoplastic colonic crypts have been recently described in Lynch syndrome patients with colorectal carcinoma, and have been proposed to be a novel indicator of Lynch syndrome. Presence of MMR-deficient nonneoplastic endometrial glands have not yet been systematically evaluated in Lynch syndrome patients. We performed MMR protein immunohistochemistry in prophylactic hysterectomies and endometrial curettings/biopsies from 27 patients with known Lynch syndrome confirmed by germline mutation analysis. A total of 56 control benign endometrial tissues were also analyzed, and included benign endometrium adjacent to MMR-deficient sporadic (MLH1 promoter hypermethylated) endometrial carcinoma (n = 9), adjacent to MMR-intact sporadic endometrial carcinoma (n = 27), and normal endometrium from hysterectomies performed for benign disease (n = 20). MMR protein deficient nonneoplastic endometrial glands were identified in 70% (19 of 27) of Lynch syndrome patients. In all 19 cases the MMR protein loss was specific for the patients' known germline mutation. None of the control cases showed loss of MMR protein expression in nonneoplastic endometrium. Our findings suggest that MMR-deficient nonneoplastic endometrial glands may be a unique, specific marker of Lynch syndrome, and may provide an important insight into the pathogenesis of Lynch syndrome-associated endometrial cancer. Evaluation of MMR protein expression of benign background endometrium in endometrial cancer patients may be further explored as a possible useful addition to the Lynch syndrome screening algorithm.

Can preoperative inflammatory markers differentiate endometrial cancer from complex atypical hyperplasia/endometrial intraepithelial neoplasia?

AIM

The aim of this study was to identify the differences between complex atypical hyperplasia/endometrial intraepithelial neoplasia (CAH/EIN) and endometrioid-type grade 1 endometrial cancer in terms of preoperative systemic inflammatory markers and to evaluate the effectiveness of such markers in predicting cancer.

METHODS

Between January 2005 and September 2018, a total of 372 patients with final histopathologic diagnoses of CAH/EIN (n = 143) and endometrioid-type grade 1 endometrial cancer (n = 229) were included in the study. Neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR) and platelet distribution width (PDW) were used as preoperative inflammatory markers. Receiver operating characteristics (ROC) analysis was used to assess the diagnostic prediction of NLR, PLR and PDW values to distinguish the two groups. Univariate and multivariate logistic regression analysis was performed by regrouping the patients according to the cut-off values found in the ROC analysis.

RESULTS

The univariate analysis revealed that advanced age, decreases in PDW and also PLR could be predictors of cancer. The cut-off values were as ≤48.9% for PDW and ≤133.3 for PLR. The values defined using ROC analysis were found to be statistically significant for PDW and PLR in identifying endometrioid grade 1 endometrial cancer. For PDW, sensitivity, specificity, positive predictive value and negative predictive value were 52.8%, 62.2%, 68.9% and 45.5%, respectively (P = 0.001); for PLR, those were 55.9%, 59.4%, 68.8% and 45.7%, respectively (P = 0.005). In multivariate analysis, advanced age (>53 years), low PDW (≤48.9%) and low PLR (≤133.3) were related to statistically significant odds ratio for diagnostic prediction to differentiate endometrioid grade 1 cases from CAH/EIN of 8.01 (P < 0.001), 1.79 (P = 0.019) and 1.73 (P = 0.025), respectively.

CONCLUSIONS

The PLR and PDW values in the preoperative blood parameters could be used to differentiate endometrial cancer from precancerous lesions.

Utility of the immunohistochemical analysis of DNA mismatch-repair proteins in endometrial hyperplasia

The utility of the expression lack of DNA mismatch-repair (MMR) proteins in the detection of Lynch syndrome in endometrial hyperplasia as precursor lesion of endometrial carcinoma has not been well-established. The study investigated the immunoexpression pattern of MMR proteins in endometrial hyperplasia from Tunisian patients. We carried out a retrospective study of 60 endometrial hyperplasias diagnosed among Tunisian patients. Expression of MLH1, MSH2, MSH6, and PMS2 proteins was performed by immunohistochemistry on whole-slide sections of archival tissues. Analysis of MLH1 promoter methylation and microsatellite alterations was conducted in appropriate cases. Microsatellite instability screening was assessed using the Bethesda panel, including BAT25, BAT26, D17S250, D2S123, and D5S346 markers. Expression of MMR proteins was observed in all hyperplasias without atypia as well as in 27 out of 29 atypical hyperplasias. Only two atypical hyperplasias exhibited expression loss of MMR proteins. A single case revealed MSH6 expression lack. Expression loss of MLH1 and PMS2 was identified in another atypical hyperplasia and was associated with hypermethylation of MLH1 promoter. This patient had no familial history of endometrial cancer at the diagnostic time. The two deficient MMR cases showed microsatellite stable pattern. In conclusion, only two endometrial hyperplasias displayed an altered pattern of MMR expression. Our results suggest the limited utility of the immunohistochemical analysis of MMR protein in the early detection of Lynch syndrome in Tunisian patients diagnosed with endometrial hyperplasias. Multicenter studies with larger sample size are needed to more explore these findings.

Mismatch Repair Protein Expression in Endometrioid Intraepithelial Neoplasia/Atypical Hyperplasia: Should We Screen for Lynch Syndrome in Precancerous Lesions?

Screening for Lynch syndrome (LS) is routinely performed in patients with endometrial carcinoma. Currently, no screening recommendations exist for LS in precancerous lesions. The study goal was to determine the incidence of abnormal protein expression in endometrioid intraepithelial neoplasia/atypical hyperplasia (EIN/AH). We analyzed mismatch repair (MMR) protein expression by immunohistochemistry in EIN/AH concurrent with MMR-deficient endometrial carcinomas, and in endometrial biopsy/curettage specimens with EIN/AH from an unselected group of patients. Of 63 patients with MMR-deficient endometrial carcinoma, 34 demonstrated loss of MLH1/PMS2 expression; 1 showed loss of PMS2 alone; 12 showed loss of MSH2/MSH6, and 15 had loss of MSH6 alone. Genetic testing identified deleterious mutations in 14 cases (LS). 15 tumors demonstrated MLH1 promoter hypermethylation. Abnormal MMR expression in EIN/AH and adjacent carcinoma was concordant in 100% of LS cases and 71% of MLH1 promoter hypermethylation cases. Of 118 patients from the unselected group with EIN/AH, 4 (3%) cases demonstrated absent expression of one or more MMR proteins. Of these, 2 patients were later confirmed to have deleterious mutations in subsequent specimens with endometrial carcinoma. The prevalence of abnormal MMR expression in EIN/AH adjacent to carcinoma and in the unselected group of patients with EIN/AH is similar to the reported prevalence of LS in endometrial carcinoma. Identifying patients at high risk for LS through abnormal MMR expression in EIN/AH provides the benefit of early surveillance, treatment and timely diagnosis for the patient and affected family members.

Analysis of DNA methylation in endometrial biopsies to predict risk of endometrial cancer

OBJECTIVE

To determine whether analysis of methylated DNA in benign endometrial biopsy (EB) specimens is associated with risk of endometrial cancer (EC).

METHODS

We identified 23 women with EBs performed at Mayo Clinic diagnosed as normal (n = 14) or hyperplasia (n = 9) and who later developed endometrial cancer after a median interval of 1 year. Cases were matched 1:1 with patients with benign EBs who did not develop EC (controls) by histology of benign EB (normal endometrium vs. endometrial hyperplasia without atypia), date of EB, age at EB, and length of post-biopsy follow-up. DNA extracted from formalin-fixed paraffin-embedded tissues underwent pyrosequencing to determine percent methylation of promoter region CpGs at 26 loci in 4 genes (ADCYAP1, HAND2, MME, RASSF1A) previously reported as methylated in EC.

RESULTS

After pathologic review, 23 matched pairs of cases and controls were identified (14 normal, 9 hyperplasia without atypia per group). Among cases, median time from benign EB to EC was 1 year (range 2 days - 9.2 years). We evaluated 26 CpG sites within 4 genes and found a consistent trend of increasing percentage of methylation from control to case to EC for all CpGs. At the gene-level, mean methylation events of ADCYAP1 and HAND2 in cases were significantly higher than control (p = 0.015 and p = 0.021, respectively). Though the other genes did not reach statistical significance, we observed an increased methylation trend among all genes. Area-under-curve (AUC) calculations (predicting future development of EC in the setting of benign EB) for ADCYAP1 and HAND2 were 0.71 (95% CI 0.55-0.88) and 0.83 (95% CI 0.64-1, respectively).

CONCLUSIONS

This proof-of-principle study provides evidence that specific methylation patterns in benign EB correlate with future development of EC.

Epigenetic Dysregulation at the Crossroad of Women's Cancer

An increasingly number of women of all age groups are affected by cancer, despite substantial progress in our understanding of cancer pathobiology, the underlying genomic alterations and signaling cascades, and cellular-environmental interactions. Though our understanding of women’s cancer is far more complete than ever before, there is no comprehensive model to explain the reasons behind the increased incidents of certain reproductive cancer among older as well as younger women. It is generally suspected that environmental and life-style factors affecting hormonal and growth control pathways might help account for the rise of women’s cancers in younger age, as well, via epigenetic mechanisms. Epigenetic regulators play an important role in orchestrating an orderly coordination of cellular signals in gene activity in response to upstream signaling and/or epigenetic modifiers present in a dynamic extracellular milieu. Here we will discuss the broad principles of epigenetic regulation of DNA methylation and demethylation, histone acetylation and deacetylation, and RNA methylation in women’s cancers in the context of gene expression, hormonal action, and the EGFR family of cell surface receptor tyrosine kinases. We anticipate that a better understanding of the epigenetics of women’s cancers may provide new regulatory leads and further fuel the development of new epigenetic biomarkers and therapeutic approaches.

Genomic Comparison of Endometrioid Endometrial Carcinoma and Its Precancerous Lesions in Chinese Patients by High-Depth Next Generation Sequencing

Endometrial intraepithelial neoplasia (EIN), also known as endometrial atypical hyperplasia (EAH) is believed to be the precursor lesion of endometrioid endometrial carcinoma (EEC). Many genetic factors play important roles in the process of carcinogenesis, however, the key genetic alterations from dysplasia to endometrial cancer remains poorly understood. Germline mutations in Lynch syndrome genes are associated with hereditary endometrial carcinoma. The role of other cancer susceptibility genes is unclear. The aim of this study was to investigate the genomic alterations of premalignant endometrial lesion and EEC, and to determine the prevalence of cancer predisposition gene mutations in an unselected endometrial carcinoma patient cohort. Here, we applied a comprehensive cancer gene panel (363 cancer-related genes) to capture the exomes of cancer-related genes. Samples were collected from 79 patients with EEC and 36 patients with EIN. Our results demonstrate that EIN harbors most of the driver events reported in EEC and for the first time we reported a high frequency of the amplification of VEGFB gene in endometrial cancer. Moreover, we identified four novel candidate cancer-associated genes (CTCF, ARHGAP35, NF1, and KDR) which may be crucial in the carcinogenesis of EEC. In addition, we identified 2 patients who had a deleterious germline mutation in Lynch syndrome genes (MLH1 and MLH2), and another 8 patients harbored germline mutations of 6 non-Lynch syndrome genes (MUTYH, GALNT12, POLE, MPL, ATM, and ERCC4) which may be associated with endometrial cancer. Larger series will have to be investigated to assess the risks and the proportion of endometrial cancers attributable to other genes.

Diagnostic value of histopathological examination results obtained during screening of patients with diagnosed atypical hyperplasia

Vulvovaginal atrophy accompanied by lower urinary tract dysfunction related to low levels of estrogen and androgens is labeled as genitourinary syndrome of menopause (GSM). Although this condition affects most postmenopausal women worldwide, it seems to be underdiagnosed and undertreated. Women should be properly advised to choose an adequate treatment modality to improve their quality of life, sexual relationships and social activity. The aim of this article is to increase knowledge of GSM. The current treatment options, both hormonal and non-hormonal, are reviewed. Topical estrogen therapy still remains the gold standard, but the demand for individually tailored therapy is growing. New treatment modalities are continuously included in clinical practice. They should consider the whole personality of a woman as well as cultural and social factors. Further studies on GSM and on the effectiveness of various treatment options are necessary to achieve this purpose.

The Epigenetic Landscape in the Treatment of Gynecologic Malignancies

The care of patients with advanced-stage or recurrent endometrial, ovarian, and cervical cancer remains clinically challenging. Despite the identification of novel therapeutics and advancements in supportive care, survival outcomes have been relatively unchanged over the past decade. In addition to established genomic alterations and the contributions of the tumor microenvironment to cancer progression, epigenetic mechanisms have emerged as important contributors to gynecologic cancer progression. DNA methylation, histone modification, and noncoding RNA expression may be important contributors to disease initiation and progression and may represent novel therapeutic targets. This article reviews the epigenetic landscape of endometrial, ovarian, and cervical cancer, describing the state of the science and discussing potential clinical applications. To date, the role of epigenetic drugs in the treatment of gynecologic cancers remains unclear, although continued progress may inform future treatment modalities.

DNA Repair Gene (XPD, XRCC4, and XRCC1) Polymorphisms in Patients with Endometrial Hyperplasia: A Pilot Study

Background

In this study, we aimed to evaluate the association between endometrial hyperplasia and DNA repair gene (XPD, XRCC4, and XRCC1) polymorphisms.

Material/Methods

There were 114 cases enrolled in the study in 4 groups: simple endometrial hyperplasia (SH) (Group 1), complex endometrial hyperplasia without atypia (CH) (Group 2), complex atypical endometrial hyperplasia (CAH) (Group 3), and normal endometrium (NE) (Group 4). Of these cases, 37 cases had SH, 36 cases had CH, 16 cases had CAH, and 25 cases had NE. To evaluate an association between atypia and DNA repair genes, we consider a group that included both SH and CH, the endometrial hyperplasia without atypia cases (Group 5). Genomic DNA was isolated from paraffin-embedded endometrial tissue collected from the Pathology Department of Gaziantep University Medical School. Polymerase chain reaction (PCR) and/or restriction fragment length polymorphism (RFLP) method was used for evaluating of XPD (−751), XRCC4 (−1394 and a variable number of tandem repeats in intron 3), and XRCC1 (−399) genes.

Results

We observed a notable distinction in patients having endometrial hyperplasia without atypia (the SH+CH group) and the CAH group in terms of XPD (−751) gene polymorphisms. A notable contrast was observed in patients with endometrial hyperplasia without atypia (the SH+CH group) and the NE group in terms of XRCC4 (VNTR intron 3) polymorphisms (P=0.026, P=0.018, respectively).

Conclusions

It was evident the DNA repair gene XPD and XRCC4 polymorphisms had a role in the pathophysiology of endometrial hyperplasia.

Methylation status of KLF4 and HS3ST2 genes as predictors of endometrial cancer and hyperplastic endometrial lesions

Endometrial carcinoma is one of the most common tumours in developed countries. In addition to the active role of genetic factors, epigenetic changes also have an important effect. The present study analysed the methylation status of kruppel like factor 4 (KLF4) and heparan sulfate‑glucosamine 3‑sulfotransferase 2 (HS3ST2) genes in three endometrial tissue types for carcinoma prediction. The sample comprised 91 women with histologically‑confirmed endometrial carcinoma (64.16±9.64 years old), 36 women with hyperplasia (53.39±9.64 years old) and 45 with no signs or symptoms of malignancy (48.53±11.11 years old). The CpG dinucleotide methylation levels were examined by quantitative pyrosequencing, and the discrimination accuracy of the model was calculated using the Random Forest classification algorithm of the area under the ROC curve (AUC). The mean values of KLF4 and HS3ST2 methylation indices were 23.83±11.39 and 8.52±2.57 in the control samples; 30.40±8.52 and 33.76±20.66 in hyperplasia and 34.72±10.79 and 34.49±18.39 in the cancerous tissues. Multinomial logistic regression indicated that the HS3ST2 CpG1 methylation status is a predictor of hyperplasia (P<0.05) and that the KLF4 CpG2 dinucleotide can predict carcinoma formation (P<0.001). The AUC value of 0.95 indicates high discrimination accuracy of the CpG nucleotides methylation status model between the controls and the two other diagnoses. The results of the present study establish the likelihood that aberrations in KLF4 and HS3ST2 gene methylation levels are important in the development of endometrial hyperplasia and carcinoma, with hyperplasia an intermediate step between healthy and tumour tissues.

Molecular changes preceding endometrial and ovarian cancer: a study of consecutive endometrial specimens from Lynch syndrome surveillance

Molecular alterations preceding endometrial and ovarian cancer and the sequence of events are unknown. Consecutive specimens from lifelong surveillance for Lynch syndrome provides a natural setting to address such questions. To molecularly define the multistep gynecological tumorigenesis, DNA mismatch repair gene mutation carriers with endometrial or ovarian carcinoma or endometrial hyperplasia were identified from a nation-wide registry and endometrial biopsy specimens taken from these individuals during 20 years of screening were collected. A total of 213 endometrial and ovarian specimens from Lynch syndrome individuals and 197 histology-matched (non-serous) samples from sporadic cases were available for this investigation. The specimens were profiled for markers linked to endometrial and ovarian tumorigenesis, including ARID1A protein expression, mismatch repair status, and tumor suppressor gene promoter methylation. In Lynch syndrome-associated endometrial and ovarian carcinomas, ARID1A protein was lost in 61-100% and mismatch repair was deficient in 97-100%, compared to 0-17% and 14-44% in sporadic cases (P = 0.000). ARID1A loss appeared in complex hyperplasia and deficient mismatch repair and tumor suppressor gene promoter methylation in histologically normal endometrium. Despite quantitative differences between Lynch syndrome and sporadic cases, ARID1A expression, mismatch repair, and tumor suppressor gene promoter methylation divided endometrial samples from both patient groups into three categories of increasing abnormality, comprising normal endometrium and simple hyperplasia (I), complex hyperplasia with or without atypia (II), and endometrial cancer (III). Complex hyperplasias without vs. with atypia were molecularly indistinguishable. In conclusion, surveillance specimens from Lynch syndrome identify mismatch repair deficiency, tumor suppressor gene promoter methylation, and ARID1A loss as early changes in tumor development. Our findings are clinically relevant for the classification of endometrial hyperplasias and have potential implications in cancer prevention in Lynch syndrome and beyond.

Models including plasma levels of sphingomyelins and phosphatidylcholines as diagnostic and prognostic biomarkers of endometrial cancer

In endometrial cancer, biomarkers for preoperative identification of patients with low risk for disease progression would enable stratification according to the extent of surgery needed, and would avoid the complications that can be associated with radical surgery. A panel of proteins, amino acids, enzymes, and miRNA has been investigated as potential biomarkers for endometrial cancer. At the time of the manuscript submission targeted metabolomics/lipidomics approaches have not been applied to biomarker research in endometrial cancer. Using electrospray ionization-tandem mass spectrometry we quantified 163 metabolites in 126 plasma samples (61 patients with endometrial cancer, 65 control patients). Three single phosphatidylcholines were identified with significantly decreased levels in patients with endometrial cancer. A diagnostic model was defined as the ratio between acylcarnitine C16 and phosphatidylcholine PCae C40:1, the ratio between proline and tyrosine, and the ratio between the two phosphatidylcholines PCaa C42:0 and PCae C44:5; which provided sensitivity of 85.25%, specificity of 69.23%, and AUC of 0.837. Addition of smoking status further improved the constructed diagnostic model (AUC = 0.855). The presence of the major prognostic factors of deep myometrial invasion and lymphovascular invasion were also associated with altered metabolite concentrations. A prognostic model for deep myometrial invasion included the ratio between two hydroxysphingomyelins SMOH C14:1 and SMOH C24:1, and the ratio between two phosphatidylcholines PCaa C40:2 and PCaa C42:6, which provided sensitivity of 81.25%, specificity of 86.36%, and AUC of 0.857. The model for lymphovascular invasion included the ratio between two phosphatidylcholines PCaa C34:4 and PCae C38:3, and the ratio between acylcarnitine C16:2 and phosphatidylcholine PCaa C38:1, which provided sensitivity of 88.89%, specificity of 84.31%, and AUC of 0.935.

Gynaecological neoplasms in common familial syndromes (Lynch and HBOC)

Recognising hereditary predisposition in a cancer patient has implications both for the patient and the patient's kindred. For the latter, cascade germline testing can reassure those not-at-risk family members while carriers can be enrolled in cancer screening and prevention programs that are medically effective and economically sustainable for health care systems. Furthermore, in many of these syndromes, ramifications of molecular phenotypes are increasing, and it is now emerging that, in addition, they convey prognostic and predictive information. Although cancer predisposition syndromes are rare, these molecular phenotypes also occur as somatic events in sporadic cancer settings. The information obtained from these molecular phenotypes, regardless of germline or somatic origin, is being incorporated into clinical management in view of their manifold significance. Thus, increasingly, bespoke management of cancer patients involves testing for both germline and somatic mutations in tumours. Lynch syndrome and BRCA-1 and BRCA-2-associated hereditary breast and ovarian cancer are hereditary cancer syndromes frequently involving the gynaecological tract but tumours associated with similar molecular alterations may also occur sporadically. Thus, the molecular phenotype of mismatch repair deficiency, microsatellite instability or hypermutator phenotype may be attributable to germline or somatic events. Similarly, homologous recombination deficiency or 'BRCAness' in ovarian cancers may be syndromic or sporadic. While hereditary syndromes are well recognised, the prognostic and predictive implications of these molecular phenotypes have only recently been elucidated and these aspects will finally ensure that molecular screening may become standard of care. Thus, nowadays pathologists are asked to designate the molecular phenotype of these cancers and then determine whether it is due to hereditary or sporadic causes.

Clonal evolution in paired endometrial intraepithelial neoplasia/atypical hyperplasia and endometrioid adenocarcinoma

Endometrial intraepithelial neoplasia (EIN) and atypical endometrial hyperplasia (AH) are histomorphologically defined precursors to endometrioid adenocarcinoma, which are unified as EIN/AH by the World Health Organization. EIN/AH harbors a constellation of molecular alterations similar to those found in endometrioid adenocarcinoma. However, the process of clonal evolution from EIN/AH to carcinoma is poorly characterized. To investigate, we performed next-generation sequencing, copy number alteration (CNA) analysis, and immunohistochemistry for mismatch repair protein expression on EIN/AH and endometrioid adenocarcinoma samples from 6 hysterectomy cases with spatially distinct EIN/AH and carcinoma. In evaluating all samples, EIN/AH and carcinoma did not differ in mutational burden, CNA burden, or specific genes mutated (all P>.1). All paired EIN/AH and carcinoma samples shared at least one identical somatic mutation, frequently in PI(3)K pathway members. Large CNAs (>10 genes in length) were identified in 83% of cases; paired EIN/AH and carcinoma samples shared at least one identical CNA in these cases. Mismatch repair protein expression matched in all paired EIN/AH and carcinoma samples. All paired EIN/AH and carcinoma samples had identical The Cancer Genome Atlas subtype, with 3 classified as "copy number low endometrioid" and 3 classified as "microsatellite instability hypermutated." Although paired EIN/AH and carcinoma samples were clonal, private mutations (ie, present in only one sample) were identified in EIN/AH and carcinoma in all cases, frequently in established cancer-driving genes. These findings indicate that EIN/AH gives rise to endometrioid adenocarcinoma by a complex process of subclone evolution, not a linear accumulation of molecular events.

Potential of RASSF1A promoter methylation as biomarker for endometrial cancer: A systematic review and meta-analysis

BACKGROUND

An epigenetic approach to explaining endometrial carcinogenesis necessitates good understanding of Ras association domain family 1 isoform A (RASSF1A) promoter methylation data from primary studies.

AIMS

Differential magnitude of reported associations between RASSF1A promoter methylation and endometrial cancer (EC) prompted a meta-analysis to obtain more precise estimates.

METHODS

Literature search yielded eight included articles. We calculated pooled odds ratios (OR) and 95% confidence intervals and subgrouped the data by race. Sources of heterogeneity were investigated with outlier analysis.

RESULTS

The pooled ORs indicated increased risk, mostly significant. The overall effect (OR 11.46) was reflected in the European outcome (OR 15.07). However, both findings were heterogeneous (I²=57-70%) which when subjected to outlier treatment, erased heterogeneity (I²=0%) and retained significance (OR 9.85-12.66). Significance of these pre- and post-outlier outcomes were pegged at P≤0.0001. Only the Asian pre-outlier (OR 6.85) and heterogeneous (I²=82%) outcome was not significant (P=0.12) but when subjected to outlier treatment, erased heterogeneity (I²=0%) and generated significance (OR 23.74, P≤0.0001).

CONCLUSIONS

Consistent increased risk associations underpinned by significance and robustness render RASSF1A with good biomarker potential for EC.

Epigenetics in endometrial carcinogenesis - part 2: histone modifications, chromatin remodeling and noncoding RNAs

Carcinogenesis is a multistep multifactorial process that involves the accumulation of genetic and epigenetic alterations. In the past two decades, there has been an exponential growth of knowledge establishing the importance of epigenetic changes in cancer. Our work focused on reviewing the main role of epigenetics in the pathogenesis of endometrial carcinoma, highlighting the reported results concerning each epigenetic mechanistic layer. In a previous review, we assessed DNA methylation alterations. The present review examines the contribution of histone modifications, chromatin remodeling and noncoding RNA alterations for endometrial carcinogenesis.

Epigenetics in endometrial carcinogenesis - part 1: DNA methylation

Carcinogenesis is a multistep multifactorial process that involves the accumulation of genetic and epigenetic alterations. In the past two decades, there has been an exponential growth of knowledge establishing the importance of epigenetic changes in cancer. Our work focused on reviewing the main role of epigenetics in the pathogenesis of endometrial carcinoma, highlighting the reported results concerning each epigenetic mechanistic layer. The present review is the first part of this work, in which we examined the contribution of DNA methylation alterations for endometrial carcinogenesis.

Comparison of lifestyle, hormonal and medical factors in women with sporadic and Lynch syndrome-associated endometrial cancer: A retrospective case-case study

Data available on lifestyle-associated hormonal and medical factors among endometrial cancer (EC)-affected women who carry the Lynch Syndrome (LS) mutation is limited. The aim of the present retrospective case study was to compare the reproductive and medical history, as well as lifestyle-associated factors, among patients with LS and sporadic EC. The study population consisted of 50 verified germline mismatch repair (MMR) gene mutation carriers diagnosed with EC, and 110 sporadic EC patients. Data were collected using postal questionnaires. Apart from the mean age at the time of the EC diagnosis (LS, 48.7 years compared with sporadic patients, 55.2 years; P<0.0001), the characteristics of sporadic and LS EC patients were similar with regard to body mass index (BMI) at age 18, 40 or at the time of the survey, and smoking and alcohol consumption. LS women reported a significantly lower rate of spontaneous abortion (P=0.043) and also more frequent use of contraceptives (P=0.004). The prevalence of co-morbidities, including diabetes, atherosclerosis, hypercholesterolemia and hypertension, was similar between the LS and the sporadic groups. A trend for a higher prevalence of endometriosis among mutation carriers was detected (16.0 vs. 8.1%, P=0.137). As anticipated, the prevalence of gastrointestinal tract, urinary tract and ovarian cancer was higher among the LS women (P<0.0001, P=0.006 and P=0.056, respectively). Co-morbidity and lifestyle-associated factors appeared to be comparable among patients with LS and sporadic EC. The reported difference in the use of contraceptives warrants further investigation. Future studies are also required to address the possible association between LS and endometriosis.

Loss of Mismatch Repair Protein Expression in Unselected Endometrial Adenocarcinoma Precursor Lesions

OBJECTIVE

The benefit of evaluating the precursor of endometrial carcinoma, endometrial hyperplasia (intraepithelial neoplasia [EIN]), for loss of mismatch repair (MMR) protein expression and Lynch syndrome has yet to be determined. The present study aims to establish the incidence and type of loss of MMR protein expression in unselected premalignant lesions of endometrial adenocarcinoma, as well as the agreement of immunohistochemical staining in pretreatment endometrial biopsy (EMB) specimens with subsequent uterine resections.

METHODS

A retrospective review identified 112 endometrial biopsies meeting criteria for endometrial EIN. Slides made from tissue microarray blocks were evaluated using antibodies against MLH1, PMS2, MSH2, and MSH6. Cases with a deficit in MLH1 were evaluated for gene promoter hypermethylation by polymerase chain reaction analysis. Fifty-four subsequent hysterectomy specimens were retrieved and assessed for MMR protein expression.

RESULTS

Of the 112 endometrial biopsies with EIN, 4.5% (5/112) exhibited loss of MMR protein expression. The majority (4/5) demonstrated a deficit of MLH1, of which all exhibited inactivation via promoter hypermethylation. A single case displayed an absence of MSH6. Age was not significantly associated with MMR deficiency. There was no significant association between MMR status in the EMB and a subsequent diagnosis of cancer. Immunohistochemical staining in all successive hysterectomy cases was concordant with the pattern observed in the EMB specimen.

CONCLUSIONS

Sporadic hypermethylation of MLH1 seems to be the primary mechanism underlying defective MMR protein expression in EIN. Among our cohort, only 1 patient (<1%) had a mutation suggestive of a hereditary inheritance. Hence, the utility of evaluating EIN for MMR protein expression as a screen for Lynch syndrome is limited, regardless of age.

Strong correlation between molecular changes in endometrial carcinomas and concomitant hyperplasia

OBJECTIVE

Endometrial cancer (EC) results from the accumulation of numerous genetic abnormalities contributing to the progression from hyperplasia to EC. Information on these various genetic changes has been primarily derived from studying groups of either hyperplasias or cancers.We evaluated both hyperplastic and EC tissue obtained from the same surgical specimens for KRAS mutations, microsatellite instability (MSI), and mismatch repair gene methylation, and results were correlated between the paired hyperplastic tissue and EC. The aim was to determine if molecular alterations appearing in ECs might also be present in the premalignant (hyperplastic) region of the tumor.

METHODS

One hundred ninety-seven cases of EC with associated hyperplasia were evaluated. DNA samples were studied using primer sets for KRAS gene codons 12/13 and for MSI utilizing the Bethesda panel. Methylation testing was performed on specimens that were microsatellite unstable using the MRC Holland SALSA MS-MLPA methylation-specific DNA detection kit.

RESULTS

Forty-one (20.8%) of 197 cancers demonstrated a KRAS mutation, with 35 (85.4%) of 41 accompanying hyperplasias also containing a KRAS mutation. Forty-five cancers (22.8%) were microsatellite unstable, with 38 (84.4%) of 45 accompanying hyperplasias also demonstrating instability. Of the 45 microsatellite unstable cancers, 28 (62.2%) demonstrated methylation in both the cancer and the accompanying hyperplasia, whereas 9 pairs (20%) showed no methylation for either the cancer or hyperplasia.

CONCLUSIONS

Approximately 95% of endometrial specimens demonstrated identical molecular findings regarding KRAS mutation and microsatellite stability in the paired cancer and hyperplastic tissue. The same methylation pattern was found in 82.2% of the studied paired samples. Our findings strongly suggest that the molecular changes of KRAS mutation, MSI, and methylation occur early in the neoplastic process. We propose that endometrial biopsies revealing only hyperplasia should be studied for these molecular alterations as an indicator of possible early carcinogenesis.

Tumor progression, metastasis, and modulators of epithelial-mesenchymal transition in endometrioid endometrial carcinoma: an update

Endometrioid endometrial carcinoma (EEC), also known as type 1 endometrial cancer (EC), accounts for over 70-80% of all cases that are usually associated with estrogen stimulation and often develops in a background of atypical endometrial hyperplasia. The increased incidence of EC is mainly confined to this type of cancer. Most EEC patients present at an early stage and generally have a favorable prognosis; however, up to 30% of EEC present as high risk tumors, which have invaded deep into the myometrium at diagnosis and progressively lead to local or extra pelvic metastasis. The poor survival of advanced EC is related to the lack of effective therapies, which can be attributed to poor understanding of the molecular mechanisms underlying the progression of disease toward invasion and metastasis. Multiple lines of evidence illustrate that epithelial-mesenchymal transition (EMT)-like events are central to tumor progression and malignant transformation, endowing the incipient cancer cell with invasive and metastatic properties. The aim of this review is to summarize the current knowledge on molecular events associated with EMT in progression, invasion, and metastasis of EEC. Further, the role of epigenetic modifications and microRNA regulation, tumor microenvironment, and microcystic elongated and fragmented glands like invasion pattern have been discussed. We believe this article may perhaps stimulate further research in this field that may aid in identifying high risk patients within this clinically challenging patient group and also lead to the recognition of novel targets for the prevention of metastasis - the most fatal consequence of endometrial carcinogenesis.

MicroRNA Methylation in Colorectal Cancer

Epigenetic alterations such as DNA methylation, histone modifications and non-coding RNA (including microRNA) associated gene silencing have been identified as a major characteristic in human cancers. These alterations may occur more frequently than genetic mutations and play a key role in silencing tumor suppressor genes or activating oncogenes, thereby affecting multiple cellular processes. In recent years, studies have shown that microRNAs, that act as posttranscriptional regulators of gene expression are frequently deregulated in colorectal cancer (CRC), via aberrant DNA methylation. Over the past decade, technological advances have revolutionized the field of epigenetics and have led to the identification of numerous epigenetically dysregulated miRNAs in CRC, which are regulated by CpG island hypermethylation and DNA hypomethylation. In addition, aberrant DNA methylation of miRNA genes holds a great promise in several clinical applications such as biomarkers for early screening, prognosis, and therapeutic applications in CRC.

Methyltransferase expression and tumor suppressor gene methylation in sporadic and familial colorectal cancer

Molecular mechanisms underlying coordinated hypermethylation of multiple CpG islands in cancer remain unclear and studies of methyltransferase enzymes have arrived at conflicting results. We focused on DNMT1 and DNMT3B, DNA methyltransferases responsible for (de novo) methylation, and EZH2, histone (H3K27) methyltransferase, and examined their roles in tumor suppressor gene (TSG) methylation patterns we have previously established in sporadic and familial cancers. Our investigation comprised 165 tumors, stratified by tissue of origin (117 colorectal and 48 endometrial carcinomas) and sporadic vs. familial disease (57 sporadic vs. 60 familial, mainly Lynch syndrome, colorectal carcinomas). By immunohistochemical evaluation, EZH2 protein expression was associated with a TSG methylator phenotype. DNMT1, DNMT3B, and EZH2 were expressed at significantly higher levels in tumor vs. normal tissues. DNMT1 and EZH2 expression were positively correlated and higher in microsatellite-unstable vs. microsatellite-stable tumors, whether sporadic or hereditary. Ki-67 expression mirrored the same pattern. Promoter methylation of the methyltransferase genes themselves was addressed as a possible cause behind their altered expression. While DNMT1 or EZH2 did not show differential methylation between normal and tumor tissues, DNMT3B analysis corroborated the regulatory role of a distal promoter region. Our study shows that methyltransferase expression in cancer depends on the tissue of origin, microsatellite-instability status, cellular proliferation, and--in the case of DNMT3B--promoter methylation of the respective gene. Translation of methyltransferase expression into DNA methylation appears complex as suggested by the fact that except for EZH2, no clear association between methyltransferase protein expression and TSG methylation was observed.

Methylation of tumor suppressor gene CDH13 and SHP1 promoters and their epigenetic regulation by the UHRF1/PRMT5 complex in endometrial carcinoma

OBJECTIVE

Epigenetic changes in cancer and precancerous lesions could be utilized as biomarkers for cancer early detection. This study aims to investigate the novel biomarkers in endometrial carcinoma, and explore their epigenetic regulation.

METHODS

Methylation of six tumor suppressor genes (CDH13, SHP1, HIN1, DKK3, CTNNA1 and PCDH8) was evaluated in 155 endometrium samples. Changes of methylation and mRNA expression after treatment with 5-Aza-2'-deoxycytidine (5-Aza-CdR) or/and trichostatin A (TSA) were investigated by MSP and qRT-PCR respectively. Co-immunoprecipitation was used to detect the interactions between UHRF1 and PRMT5 proteins.

RESULTS

CDH13 and SHP1 promoters were highly methylated (81.36% and 86.44%, respectively) in endometrial carcinoma, while CDH13 promoter methylation was also present in complex hyperplasia and atypical hyperplasia (51.72% and 50.00%, respectively). Methylation of CDH13 and SHP1 promoters was associated with age and tumor differentiation or muscular infiltration depth. CDH13 and SHP1 promoters were completely methylated in endometrial carcinoma cell lines and were partially reversed by 5-Aza-CdR or TSA to induce mRNA levels (P<0.01). After combined treatment with these two agents, methylation of CDH13 and SHP1 promoters was completely reversed and expression of their mRNA was significantly increased (P<0.01). Moreover, PRMT5 could bind to UHRF1 and down-regulated by 5-Aza-CdR and/or TSA treatment (P<0.05).

CONCLUSIONS

Our data demonstrate for the first time that SHP1 methylation has high specificity for diagnosis of endometrial carcinoma, while CDH13 promoter methylation plays a role in the earlier stage. Furthermore, UHRF1 could form a complex with PRMT5 to contribute to the endometrial carcinogenesis.

Identification of subgroup-specific miRNA patterns by epigenetic profiling of sporadic and Lynch syndrome-associated colorectal and endometrial carcinoma

Background

Altered expression of microRNAs (miRNAs) commonly accompanies colorectal (CRC) and endometrial carcinoma (EC) development, but the underlying mechanisms and clinicopathological correlations remain to be clarified. We focused on epigenetic mechanisms and aimed to explore if DNA methylation patterns in tumors depend on DNA mismatch repair (MMR) status, sporadic vs. Lynch-associated disease, and geographic origin (Finland vs. Australia). Treatment of cancer cell lines with demethylating agents revealed 109 significantly upregulated miRNAs. Seven met our stringent criteria for possible methylation-sensitive miRNAs and were used to screen patient specimens (205 CRCs and 36 ECs) by methylation-specific multiplex ligation-dependent probe amplification.

Results

Three miRNAs (129-2, 345, and 132) with low methylation levels in normal tissue and frequent hypermethylation in tumors were of particular interest. Hypermethylation of miR-345 and miR-132 associated with MMR deficiency in CRC regardless of geographic origin, and hypermethylation of miR-132 distinguished sporadic MMR-deficient CRC from Lynch-CRC. Finally, hypermethylation of miRNAs stratified 49 endometrial hyperplasias into low-methylator (simple hyperplasia) and high-methylator groups (complex hyperplasia with or without atypia) and suggested that miR-129-2 methylation in particular could serve as a marker of progression in early endometrial tumorigenesis.

Conclusions

Our study identifies miR-345 and miR-132 as novel differentially methylated miRNAs in CRC, thereby facilitating sub-classification of CRC and links miR-129-2 methylation to early endometrial tumorigenesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13148-015-0059-3) contains supplementary material, which is available to authorized users.

Importance of promoter methylation of GATA4 and TP53 genes in endometrioid carcinoma of endometrium

BACKGROUND

Epigenetic changes are considered to be a frequent event during tumor development. Various methylation changes have been identified and show promise as potential cancer biomarkers. The aim of this study was to investigate promoter methylation of GATA4 and TP53 genes in endometrioid carcinoma of endometrium.

METHODS

To search for promoter methylation of GATA4 and TP53 genes we used methylation-specific PCR (MSP) to compare the methylation status of 54 patients with endometrioid carcinoma of endometrium and 18 patients with normal endometrial tissue.

RESULTS

In our study MSP revealed GATA4 promoter methylation in 44 of 54 in the carcinoma group (81.5%), and in none of the control group. No methylation was observed in TP53 gene.

CONCLUSIONS

In conclusion, our study showed that there is significantly higher methylation in GATA4 gene in the endometrial cancer group compared with samples of non-neoplastic endometrium. The finding suggests the importance of hypermethylation of this gene in endometrial carcinogenesis and could have implications for future diagnostic and therapeutic strategies for endometrial cancer based on epigenetic changes.

Combined colonoscopy and endometrial biopsy cancer screening results in women with Lynch syndrome

OBJECTIVE

Endometrial biopsy (EMBx) and colonoscopy performed under the same sedation is termed combined screening and has been shown to be feasible and to provide a less painful and more satisfactory experience for women with Lynch syndrome (LS). However, clinical results of these screening efforts have not been reported. The purpose of this study was to evaluate the long-term clinical outcomes and patient compliance with serial screenings over the last 10.5 years.

METHODS

We retrospectively analyzed the data for 55 women with LS who underwent combined screening every 1-2 years between 2002 and 2013. Colonoscopy and endometrial biopsy were performed by a gastroenterologist and a gynecologist, with the patient under conscious sedation.

RESULTS

Out of 111 screening visits in these 55 patients, endometrial biopsies detected one simple hyperplasia, three complex hyperplasia, and one endometrioid adenocarcinoma (FIGO Stage 1A). Seventy-one colorectal polyps were removed in 29 patients, of which 29 were tubular adenomas. EMBx in our study detected endometrial cancer in 0.9% (1/111) of surveillance visits, and premalignant hyperplasia in 3.6% (4/111) of screening visits. No interval endometrial or colorectal cancers were detected.

CONCLUSIONS

Combined screening under sedation is feasible and less painful than EMBx alone. Our endometrial pathology detection rates were comparable to yearly screening studies. Our results indicate that screening of asymptomatic LS women with EMBx every 1-2 years, rather than annually, is effective in the early detection of (pre)cancerous lesions, leading to their prompt definitive management, and potential reduction in endometrial cancer.

Discovery and validation of methylation markers for endometrial cancer

The prognosis of endometrial cancer is strongly associated with stage at diagnosis, suggesting that early detection may reduce mortality. Women who are diagnosed with endometrial carcinoma often have a lengthy history of vaginal bleeding, which offers an opportunity for early diagnosis and curative treatment. We performed DNA methylation profiling on population-based endometrial cancers to identify early detection biomarkers and replicated top candidates in two independent studies. We compared DNA methylation values of 1,500 probes representing 807 genes in 148 population-based endometrial carcinoma samples and 23 benign endometrial tissues. Markers were replicated in another set of 69 carcinomas and 40 benign tissues profiled on the same platform. Further replication was conducted in The Cancer Genome Atlas and in prospectively collected endometrial brushings from women with and without endometrial carcinomas. We identified 114 CpG sites showing methylation differences with p values of ≤ 10(-7) between endometrial carcinoma and normal endometrium. Eight genes (ADCYAP1, ASCL2, HS3ST2, HTR1B, MME, NPY and SOX1) were selected for further replication. Age-adjusted odds ratios for endometrial cancer ranged from 3.44 (95%-CI: 1.33-8.91) for ASCL2 to 18.61 (95%-CI: 5.50-62.97) for HTR1B. An area under the curve (AUC) of 0.93 was achieved for discriminating carcinoma from benign endometrium. Replication in The Cancer Genome Atlas and in endometrial brushings from an independent study confirmed the candidate markers. This study demonstrates that methylation markers may be used to evaluate women with abnormal vaginal bleeding to distinguish women with endometrial carcinoma from the majority of women without malignancy.

Epigenetic mechanisms in the pathogenesis of Lynch syndrome

Inherited defects in the DNA mismatch repair (MMR) system, MLH1, MSH2, MSH6, and PMS2 genes, underlie Lynch syndrome, one of the most prevalent cancer syndromes in man. The syndrome offers a model for cancers arising through MMR defects and microsatellite instability, which applies to ~ 15% of all colorectal, endometrial, and other cancers. Lynch syndrome also illustrates the significance of the epigenetic component in cancer development. Inactivation of tumor suppressor genes by epigenetic mechanisms is an acquired property of many tumors developing in Lynch syndrome. Furthermore, constitutional epimutations of MMR genes may explain a proportion of mutation-negative families lacking MLH1 or MSH2 protein expression in tumor tissue. This review provides an update of the molecular basis of Lynch syndrome by focusing on the role of epigenetic mechanisms in the pathogenesis of the disease.

High nuclear expression of HDGF correlates with disease progression and poor prognosis in human endometrial carcinoma

Aims. This study examined the correlation between high nuclear expression of hepatoma-derived growth factor (HDGF) and clinicopathologic data in endometrial carcinoma (EC), including patient survival. Methods. One hundred and twenty-two endometrial carcinoma (EC) patients from 2002 to 2008 were reviewed in the study. HDGF expression in tumor tissues was examined using immunohistochemistry (IHC), and its association with clinicopathological parameters was evaluated. Tumors with 80% or more nuclei staining were regarded as high expression and tumors with less than 80% nuclei staining considered as low expression. Results and Conclusions. Immunohistochemical analysis revealed that HDGF was expressed in both the nucleus and cytoplasm. High nuclear expression of HDGF was positively correlated with FIGO stage (P = 0.032), but not associated with other clinical features, such as histological grading or lymph node status. Patients with high expression of HDGF had poorer overall survival rates than those with low expression of HDGF (P = 0.001). However, multivariate analyses showed that high nuclear expression of HDGF protein was not an independent predictor of prognosis for EC patients (P = 0.111). Our results suggest that high nuclear expression of HDGF is a potential unfavorable factor for the progression and prognosis of EC.

NF-κB and COX-2 expression in nonmalignant endometrial lesions and cancer

OBJECTIVES

To examine the immunohistochemical expression of cyclooxygenase-2 (COX-2) and nuclear factor-κB (NF-κB) in benign endometrial polyps (EPs), endometrial hyperplasia (EH), endometrial intraepithelial neoplasia (EIN), and endometrioid endometrial cancer (EC).

METHODS

The immunohistochemical expression of COX-2 and NF-κB was performed using an Aperio Scanscope XT automated system in 218 patients with endometrioid EC and 107 patients with nonmalignant endometrial lesions: 53 with benign EPs, 37 with EH, and 17 with EIN.

RESULTS

COX-2 and NF-κB p50 expression were significantly lower in EC compared with nonmalignant lesions. We observed significant decreased NF-κB p65 expression in EC vs EPs (P < .001) and EH (P = .014) as well as in EIN vs. EPs (P = .01). For patients with EC, COX-2 correlated positively with NF-κB p65 and NF-κB p50 (P < .001). Grade 3 tumors had a higher mean expression of NF-κB p65 (P = .03). NF-κB p50, NF-κB p65, and COX-2 expression had no impact on survival.

CONCLUSIONS

We conclude that COX-2 and NF-κB expression are lower in EC compared with nonmalignant endometrial lesions. COX-2 and NF-κB expression have no prognostic value in EC.

Molecular pathogenesis of endometrial cancers in patients with Lynch syndrome

BACKGROUND

The authors hypothesized that Lynch syndrome (LS)-associated endometrial cancer (EC) develops from morphologically normal endometrium that accumulates enough molecular changes to progress through a continuum of hyperplasia to carcinoma, similar to sporadic EC. The primary objective of the current study was to determine whether LS-associated EC involves progression through a preinvasive lesion. The secondary objective was to identify molecular changes that contribute to endometrial carcinogenesis in patients with LS.

METHODS

Women with a confirmed mismatch repair gene mutation for LS who were undergoing a prophylactic or therapeutic hysterectomy were eligible. Cases and controls were matched for EC and hyperplasia based preferentially on age and histology. Mutation status of phosphatidylinositol 3-kinase (PIK3CA); KRAS; AKT; LKB1; catenin (cadherin-associated protein), beta 1, 88kDa (CTNNB1); and phosphatase and tensin homolog (PTEN) protein loss was assessed.

RESULTS

Concurrent complex atypical hyperplasia (CAH) was found in EC in 11 cases of LS (39.3%) and 21 sporadic cases (46.6%). Loss of PTEN expression was common in both sporadic (69%) and LS-associated EC (86.2%). There was no significant difference noted with regard to the frequency of KRAS mutations in cases of sporadic EC (10.3%) compared with LS-associated EC (3.4%). AKT and LKB1 mutations were rarely observed. Mutations in PIK3CA and CTNNB1 occurred more frequently in cases of sporadic EC compared with LS-associated EC.

CONCLUSIONS

Hyperplasia, particularly CAH, is part of the preinvasive spectrum of disease in LS-associated EC, as indicated by the presence of complex hyperplasia and CAH in cases of LS. Although loss of PTEN is common in both LS and sporadic EC cases, there was a lack of additional mutations in LS-associated EC cases. This suggests that in the context of the mismatch repair defects in LS, fewer additional molecular changes are required to progress from preinvasive lesions to 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.

Causes of death of mutation carriers in Finnish Lynch syndrome families

Lynch syndrome (LS) is an autosomal dominant cancer syndrome including increased life-long risk for colorectal (CRC) and endometrial (EC) cancer, but also for cancers of other types. The risk for CRC is up to 70-80 % and for EC up to 50-60 %. Due to screening and early diagnosing the mortality related to CRC and EC seems to be low. In spite of many studies on surveillance of mutation carriers, there is no comprehensive evaluation on causes of death in LS families. The disease history and cause of death of all the deceased, tested mutation carriers and their mutation negative relatives in the Finnish LS families (N = 179) was examined utilizing hospital records and relevant national registries. Out of 1069 mutation carriers 151 had succumbed; 97 (64 %) from cancer. Out of 1146 mutation-negative family 44 members had died; 11 (25 %) of them from cancer. In 12 (7.7 %) of the deceased mutation carriers no cancer had been diagnosed. The mean age of death from cancer was 63.2 years vs. 68.8 years from non-cancer causes. Only 7.9 % of the patients with CRC had died from CRC and 5 % of those with EC, respectively. 61 % of the cancer deaths were related to extra-colonic, extra-endometrial cancers. The cumulative overall and cancer specific death rates were significantly increased in Mut+ compared to Mut- family members. Even surveillance yields decrease in the life-long risk and mortality of the most common cancers CRC and EC in LS, almost all mutation carriers will contract with cancer, and two thirds of the deceased have died from cancer. This should be taken in account in genetic counseling. Mutation carriers should be encouraged to seek help for abnormal symptoms.

Regulation of the expression of CLU isoforms in endometrial proliferative diseases

Clusterin (CLU) is a nearly ubiquitous multifunctional protein synthesized in different functionally divergent isoforms, sCLU and nCLU, playing a crucial role by keeping a balance between cell proliferation and death. Studying in vivo CLU expression we found a higher mRNA expression both in neoplastic and hyperplastic tissues in comparison to normal endometria; in particular, by RT-qPCR we demonstrated an increase of the specific sCLU isoform in the neoplastic and hyperplastic endometrial diseases. On the contrary, no CLU increase was detected at the protein level. The CLU gene transcriptional activity was upregulated in the hyperplastic and neoplastic tissues, indicating the existence of a fine post-trans-criptional regulation of CLU expression possibly responsible for the protein decrease in the malignant disease. A specific CLU immunoreactivity was present in all the endometrial glandular cells in comparison to the other cellular compartments where CLU immunoreactivity was lower or absent. In conclusion, our results suggest the existence of a complex regulatory mechanism of CLU gene expression during the progression from normal to malignant cells, possibly contributing to endometrial carcinogenesis. Moreover, the specific alteration of the sCLU:nCLU ratio associated with the pathological stage, suggests a possible usage of CLU as molecular biomarker for the diagnosis/prognosis of endometrial proliferative diseases.