Classification of endometrial carcinoma: more than two types

Endometrial cancer prognosis correlates with the expression of L1CAM and miR34a biomarkers

Background

Patients with endometrial cancer (EC) and presumably with good prognosis may develop a recurrence indicating that the classification of this tumor is still not definitive and that new markers are needed to identify a subgroup at risk of relapse. The cell adhesion molecule L1CAM is highly expressed in several human carcinomas and has recently been described as a new marker for endometrial and ovarian carcinomas. The aim of this study was to determine the relevance of L1CAM in recurrent EC.

Methods

In this work we have analyzed, by immunohistochemical and RT-qPCR analysis, the expression of L1CAM in a cohort of 113 endometrial cancers at different stages, which 50% have relapsed. As a predictor of good outcome, the tumors were also analyzed for the expression of miR-34a, a post-transcriptional regulator of L1CAM.

Results

Among metastatic EC, the highest levels (60%) and the median level (24%) of L1CAM in tumors correlate with the progression, suggesting that the expression of this molecule is linked to the tumor component most involved in metastatic processes. We also found an inverse correlation between miR-34a and L1CAM protein expression, suggesting that miR-34a is a positive prognostic marker of EC.

Conclusions

Our results demonstrate the expression of L1CAM and miR-34a in EC as prognostic factors that identify subgroup of patients at high risk of recurrence suggesting for them more aggressive schedules of treatment.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0816-1) contains supplementary material, which is available to authorized users.

Overexpression of HOMER2 predicts better outcome in low-grade endometrioid endometrial adenocarcinoma

We have previously shown that HOMER2 (Homer scaffolding protein 2), a protein coding gene, was highly expressed in low grade (LG) endometrioid adenocarcinoma (EAC) of the uterus. The role of HOMER2 in endometrial cancer (EC) is widely unknown; therefore, the aim of this study was to determine the expression and the predictive value of HOMER2 protein expression in series of patients with EC. HOMER2 protein expression was detected on paraffin-embedded tissues from 336 cases using immunohistochemistry (IHC). Tumours were categorised in two groups; group 1 (EAC, FIGO grade 1 and 2; n = 191) and group 2 (all other subtypes including grade 3 EAC; n = 145). Statistical analysis was performed to evaluate associations between HOMER2 protein expression and pathological parameters (histological type, grade, stage, lymphovascular invasion, myometrial depth of invasion) and patient outcome [progression-free survival (PFS) and cancer-specific survival (CSS)]. HOMER2 was significantly overexpressed in group 1 compared to group 2 cancers (67% versus 30%; p < 0.001) and with low tumour grade (p < 0.001). In group 1, HOMER2 overexpression was an independent prognostic factor for improved CSS (adjusted-hazard ratio 0.28; 95% confidence interval 0.08-0.96; p = 0.042). HOMER2 expression was not associated with survival in group 2 (p > 0.05). This is the first study of HOMER2 protein expression in EC. We speculate that HOMER2 may be involved in tumourigenesis of endometrioid uterine tumours and suggest that HOMER2 should be studied further for potential clinical and therapeutic applications.

Establishment of a nine-gene prognostic model for predicting overall survival of patients with endometrial carcinoma

Endometrial carcinoma (EC) is the most common malignant tumor of the female genital tract in developed countries. The prognosis of early stage EC is favorable, but a subset faces high risk of cancer progression or recurrence. EC has a poor prognosis upon progression to advanced or metastatic stages. Therefore, our goal is to build a robust prognostic model for predicting overall survival (OS) in EC patients. In this study, 1571 genes were identified as being associated with OS based on genomewide expression profiles using a training dataset. Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that these genes were involved in various cancer-related signaling pathways. Nine signature genes were further selected using stepwise selection, and their potential role in the development of EC was demonstrated by performing differential expression analysis between EC and normal uterine tissues. A prognostic model that aggregated these nine signature genes was ultimately established and effectively divided EC patients into two risk groups. OS for patients in the high-risk group was significantly poorer compared with that of the low-risk group. This nine-gene model was subsequently validated and evaluated using the TCGA dataset and shown to have a high discriminating power to distinguish EC patients with an elevated risk of mortality based on the FIGO staging system and other prognostic factors. This study provides a novel prognostic model for the identification of EC patients with elevated risk of mortality and will help to improve our understanding of the underlying mechanisms involved in prognostic EC factors.

Expression and prognostic value of miRNA-29b in peripheral blood for endometrial cancer

AIM

We explored the role of miR-29b expression in endometrial cancer (EC) progression and patient prognosis.

MATERIALS & METHODS

Patients with primary or metastatic EC (n = 356), patients with endometrial benign tumors (n = 149) and healthy female subjects (n = 155) were collected. We assessed the diagnostic value of miR-29b expression for EC using a receiver operating characteristic curve.

RESULTS

The miR-29b expressions were lower in patients with primary or metastatic EC. Using miR-29b expression to diagnose EC produced 0.976 area under the curve, 96.1% sensitivity and 97.9% specificity. Cox proportional hazard regression model verified a low miR-29b expression and is an unfavorable prognostic indicator for EC.

CONCLUSION

We conclude that downregulated miR-29b expression correlates with poor EC prognosis and is helpful to evaluate the EC prognosis.

Computational development of a molecular-based approach to improve risk stratification of endometrial cancer patients

Histological classification and staging are the gold standard for the prognosis of endometrial cancer (EC). However, in morphologically intermediate and doubtful cases this approach results largely insufficient, defining the need for better classification criteria.

In this work we developed an algorithm that based on EC genetic alterations and in combination with the current histological classification, improves EC patients prognostic stratification, in particular in doubtful cases. A panel of 26 cancer related genes was analyzed in 89 EC patients and somatic functional mutations were investigated in association with different histology and outcome.

An unsupervised hierarchical clustering analysis revealed that two groups of patients with different tumor grade and different prognosis can be distinguished by mutational profile. In particular, the mutational status of APC, CTNNB1, PIK3CA, PTEN, SMAD4 and TP53 resulted to be principal drivers of prognostic clustering. Consistently, a decisional tree generated by a data mining approach summarizes the consequential molecular criteria for patients prognostic stratification.

The model proposed by this work provides the clinician with a tool able to support the prognosis of EC patients and consequently drives the choice of the most appropriated therapeutic strategy and follow up.

Transformed Follicular Lymphoma (TFL) Predicts Outcome in Advanced Endometrial Cancer

Background: Transformed follicular lymphoma (TFL, ZC3H12D) was identified as a candidate tumor suppressor gene that contributes to cell-cycle arrest through regulation of Rb phosphorylation, but the clinical impact of TFL is unknown. The goal of this study was to evaluate the prognostic significance of TFL expression in advanced endometrial cancer.Methods: Tissue samples were obtained from 103 patients with Federation Internationale des Gynaecologistes et Obstetristes stage III-IV endometrial cancer. Associations between TFL expression and outcomes were evaluated using the Kaplan-Meier method and multivariate Cox proportional hazards regression models.Results: There were 24 TFL-low cases (23.3%) and the 10-year progression-free survival (PFS) and overall survival (OS) in these cases were lower than those for patients with normal TFL expression in univariate analysis (PFS, P = 0.003; OS, P = 0.106). In multivariate analysis, TFL status was a significant predictor for PFS [HR = 2.76; 95% confidence interval (CI), 1.45-5.28; P = 0.002] and OS (HR = 1.94; 95% CI, 0.91-4.11; P = 0.085), adjusted for covariates. The TFL gene maps to human chromosome 6q25.1, where estrogen receptor alpha (ERα) gene ESR1 is also located. Lack of ERα expression is a poor prognostic factor in early endometrial cancer. Among 41 ERα-low patients, 10-year PFS was significantly lower in 15 TFL-low cases (univariate analysis, P = 0.055; multivariate analysis, HR = 4.70; 95% CI, 1.68-13.20; P = 0.003).Conclusions: We identified TFL as a strong independent prognostic factor, regardless of ERα status.Impact: An investigation of the mechanism underlying tumor suppression by TFL may lead to new therapies for patients with advanced endometrial cancer. Cancer Epidemiol Biomarkers Prev; 27(8); 963-9. ©2018 AACR.

LncRNA MIR22HG negatively regulates miR-141-3p to enhance DAPK1 expression and inhibits endometrial carcinoma cells proliferation

Emerging evidence has indicated that long non-coding RNAs (lncRNAs) play critical roles in tumor development and progression. Recent studies reported that lncRNA MIR22HG could play important roles in hepatocellular carcinoma and lung cancer progression. However, the expression and underlying mechanism of MIR22HG in endometrial cancer (EC) remain unclear. In the present study, qRT-PCR showed that MIR22HG expression was significantly downregulated in EC tissues. In vitro function assays showed that increased MIR22HG expression significantly inhibited EC cells proliferation, induced EC cells apoptosis, and arrested EC cells in G0/G1 phase. Furthermore, miR-141-3p was identified and confirmed to be the target of MIR22HG. Subsequently, DAPK1 was confirmed to be regulated by MIR22HG and miR-141-3p, and could play a positive role in inhibiting EC cells proliferation. Collectively, these data demonstrated that lncRNA MIR22HG could act as a tumor suppressor and inhibited EC cells proliferation through regulating miR-141-3p/DAPK1 axis, which provides a new therapeutic target for EC treatment.

PIK3CA and p53 Mutations by Next Generation Sequencing in Lymphoepithelioma-Like Carcinoma of the Endometrium

Lymphoepithelioma-like carcinoma of the endometrium is a very rare variant of endometrial carcinoma characterized by syncytial nests of pleomorphic epithelial cells and heavy infiltration of the stroma by lymphocytes (in particular CD8 cytotoxic T-lymphocytes) and plasma cells. Until now, only five cases have been characterized in this location. This report describes the clinicopathological and the molecular features of this unusual tumor. In particular, using the next generation sequencing (NGS) technique, we have demonstrated that this tumor could be associated with PIK3CA and p53 gene mutations. These data have not been reported to date and suggest that lymphoepithelioma-like carcinoma of the endometrium shares common molecular features with high grade endometrioid and serous-like endometrial carcinoma which are associated with poor outcome. Nevertheless, in endometrial lymphoepithelioma-like carcinoma, the alterations on cell cycle, apoptosis, and/or senescence secondary to p53 mutations could potentially be counterbalanced by the antitumoral response induced by CD8 cytotoxic T-lymphocytes numerous in these tumors.

Peritumoral granulomatous reaction in endometrial carcinoma: association with DNA mismatch repair protein deficiency, particularly loss of PMS2 expression

AIMS

The observation of peritumoral granulomatous reactions (PGRs) in two endometrial carcinomas (ECs) with a PMS2-deficient/MLH1-intact expression pattern led us to investigate whether PGRs in EC were specifically associated with DNA mismatch repair (MMR) protein deficiency, particularly PMS2 loss.

METHODS AND RESULTS

Hysterectomy specimens from 22 MMR protein-intact and 54 MMR protein-deficient ECs were reviewed with specific attention to the presence of a PGR and a tumour-associated lymphoid reaction [including tumour-infiltrating lymphocytes (TILs) and stromal lymphoid infiltrates]. The MMR protein-deficient ECs included 22 cases with combined MLH1/PMS2 loss, 11 with combined MSH2/MSH6 loss, 11 with isolated MSH6 loss, and 10 with PMS2 loss but intact MLH1 staining (including the two 'index' cases). Overall, PGRs were identified in seven of 54 (13%) MMR protein-deficient ECs, five of which showed a PMS2-deficient/MLH1-intact immunophenotype; three of these patients had germline PMS2 mutations and one additional patient had a germline MSH6 mutation. None of the MMR protein-intact tumours showed a PGR. Although five of the seven PGR-positive ECs had a high-grade histological component, six were stage I. Most ECs with PGRs also showed TILs and stromal lymphoid reactions, similarly to MMR protein-deficient ECs in general.

CONCLUSIONS

MMR protein-deficient ECs, particularly those with PMS2 loss, occasionally show PGRs in addition to stromal lymphoid infiltrates and TILs. Therefore, PGRs could be considered to constitute a histological prompt for consideration of Lynch syndrome. The potential prognostic significance of PGRs in EC requires further study.

Clinical impact of endometrial cancer stratified by genetic mutational profiles, POLE mutation, and microsatellite instability

BACKGROUND

The molecular characterization of endometrial cancer (EC) can facilitate identification of various tumor subtypes. Although EC patients with POLE mutations reproducibly demonstrate better prognosis, the outcome of patients with microsatellite instability (MSI) remains controversial. This study attempted to interrogate whether genetic stratification of EC can identify distinct subsets with prognostic significance.

MATERIALS AND METHODS

A cohort of 138 EC patients who underwent surgical resection with curative intent was enrolled. Sanger sequencing was used to evaluate mutations in the POLE and KRAS genes. MSI analysis was performed using four mononucleotide repeat markers and methylation status of the MLH1 promoter was measured by a fluorescent bisulfite polymerase chain reaction (PCR). Protein expression for mismatch repair (MMR) proteins was evaluated by immunohistochemistry (IHC).

RESULTS

Extensive hypermethylation of the MLH1 promoter was observed in 69.6% ECs with MLH1 deficiency and 3.5% with MMR proficiency, but in none of the ECs with loss of other MMR genes (P < .0001). MSI-positive and POLE mutations were found in 29.0% and 8.7% EC patients, respectively. Our MSI analysis showed a sensitivity of 92.7% for EC patients with MMR deficiency, and a specificity of 97.9% for EC patients with MMR proficiency. In univariate and multivariate analyses, POLE mutations and MSI status was significantly associated with progression-free survival (P = 0.0129 and 0.0064, respectively) but not with endometrial cancer-specific survival.

CONCLUSIONS

This study provides significant evidence that analyses of proofreading POLE mutations and MSI status based on mononucleotide repeat markers are potentially useful biomarkers to identify EC patients with better prognosis.

TGF-β1 stimulates migration of type II endometrial cancer cells by down-regulating PTEN via activation of SMAD and ERK1/2 signaling pathways

PTEN acts as a tumor suppressor primarily by antagonizing the PI3K/AKT signaling pathway. PTEN is frequently mutated in human cancers; however, in type II endometrial cancers its mutation rate is very low. Overexpression of TGF-β1 and its receptors has been reported to correlate with metastasis of human cancers and reduced survival rates. Although TGF-β1 has been shown to regulate PTEN expression through various mechanisms, it is not yet known if the same is true in type II endometrial cancer. In the present study, we show that treatment with TGF-β1 stimulates the migration of two type II endometrial cancer cell lines, KLE and HEC-50. In addition, TGF-β1 treatment down-regulates both mRNA and protein levels of PTEN. Overexpression of PTEN or inhibition of PI3K abolishes TGF-β1-stimulated cell migration. TGF-β1 induces SMAD2/3 phosphorylation and knockdown of common SMAD4 inhibits the suppressive effects of TGF-β1 on PTEN mRNA and protein. Interestingly, TGF-β1 induces ERK1/2 phosphorylation and pre-treatment with a MEK inhibitor attenuates the suppression of PTEN protein, but not mRNA, by TGF-β1. This study provides important insights into the molecular mechanisms mediating TGF-β1-induced down-regulation of PTEN and demonstrates an important role of PTEN in the regulation of type II endometrial cancer cell migration.

Adjuvant chemoradiotherapy versus radiotherapy alone in high-risk endometrial cancer: A systematic review and meta-analysis

BACKGROUND

The benefits of adjuvant chemoradiotherapy (CRT) for high-risk endometrial cancer (HREC) in International Federation of Gynecology and Obstetrics (FIGO) stages I-III remain controversial. A systematic review and meta-analysis was conducted to evaluate the clinical effectiveness and safety of postoperative CRT over radiotherapy (RT) alone, exclusively for patients with HREC for the following key endpoints: overall survival (OS), progression-free survival (PFS), the local recurrence rate, the distant metastasis rate, cancer-specific survival (CSS), grade III/IV acute and late toxicities, and the small bowel obstruction rate.

METHODS

Five databases, namely, PubMed, EMBASE, Cochrane Library, Web of Science and ClinicalTrials.gov, were systematically explored and supplemented by manual searching to identify relevant studies published before Dec 9, 2017. Only prospective randomized controlled trials (RCTs) conducted for HREC comparing CRT and RT alone after surgery were included. All statistical analyses were performed using RevMan Version 5.3 software.

RESULTS

Six eligible trials involving 2105 patients were identified for the final meta-analysis (CRT: n = 1064; RT: n = 1041). No statistically significant differences were evident between the CRT and RT groups regarding OS (n = 2105, RR = 1.02, 95% CI 0.98-1.06, P = 0.40). Additionally, no differences were apparent in terms of the local recurrence rate (n = 690, RR = 0.48, 95% CI 0.19-1.18, P = 0.11) or distant metastasis rate (n = 1445, RR = 0.94, 95% CI 0.72-1.23, P = 0.67). However, CRT significantly prolonged overall five-year PFS (80.2% vs. 74.5%, +5.7%; RR = 1.08, P = 0.005) and five-year CSS (86.1% vs. 79.0%, +7.1%; RR = 1.09, P = 0.03). A higher incidence of grade III/IV toxicities (P < 0.00001) was evident with CRT, while grade III/IV late toxicities and the small bowel obstruction rate were not significantly different between the two groups.

CONCLUSIONS

For patients with endometrial cancers with stage I-III risk factors, adjuvant CRT can significantly improve PFS and CSS compared with RT. With the exception of increased acute toxicities, CRT is well accepted and tolerated in HREC patients.

Combined ASRGL1 and p53 immunohistochemistry as an independent predictor of survival in endometrioid endometrial carcinoma

OBJECTIVE

In clinical practise, prognostication of endometrial cancer is based on clinicopathological risk factors. The use of immunohistochemistry-based markers as prognostic tools is generally not recommended and a systematic analysis of their utility as a panel is lacking. We evaluated whether an immunohistochemical marker panel could reliably assess endometrioid endometrial cancer (EEC) outcome independent of clinicopathological information.

METHODS

A cohort of 306 EEC specimens was profiled using tissue microarray (TMA). Cost- and time-efficient immunohistochemical analysis of well-established tissue biomarkers (ER, PR, HER2, Ki-67, MLH1 and p53) and two new biomarkers (L1CAM and ASRGL1) was carried out. Statistical modelling with embedded variable selection was applied on the staining results to identify minimal prognostic panels with maximal prognostic accuracy without compromising generalizability.

RESULTS

A panel including p53 and ASRGL1 immunohistochemistry was identified as the most accurate predictor of relapse-free and disease-specific survival. Within this panel, patients were allocated into high- (5.9%), intermediate- (29.5%) and low- (64.6%) risk groups where high-risk patients had a 30-fold risk (P<0.001) of dying of EEC compared to the low-risk group.

CONCLUSIONS

P53 and ASRGL1 immunoprofiling stratifies EEC patients into three risk groups with significantly different outcomes. This simple and easily applicable panel could provide a useful tool in EEC risk stratification and guiding the allocation of treatment modalities.

Type I Versus Type II Endometrial Cancer: Differential Impact of Comorbidity

Objective

Two distinct types of endometrial carcinoma (EC) with different etiology, tumor characteristics, and prognosis are recognized. We investigated if the prognostic impact of comorbidity varies between these 2 types of EC. Furthermore, we studied if the recently developed ovarian cancer comorbidity index (OCCI) is useful for prediction of survival in EC.

Materials and Methods

This nationwide register-based cohort study was based on data from 6487 EC patients diagnosed in Denmark between 2005 and 2015. Patients were assigned a comorbidity index score according to the Charlson comorbidity index (CCI) and the OCCI. Kaplan-Meier survival statistics and adjusted multivariate Cox regression analyses were used to investigate the differential association between comorbidity and overall survival in types I and II EC.

Results

The distribution of comorbidities varied between the 2 EC types. A consistent association between increasing levels of comorbidity and poorer survival was observed for both types. Cox regression analyses revealed a significant interaction between cancer stage and comorbidity indicating that the impact of comorbidity varied with stage. In contrast, the interaction between comorbidity and EC type was not significant. Both the CCI and the OCCI were useful measurements of comorbidity, but the CCI was the strongest predictor in this patient population.

Conclusions

Comorbidity is an important prognostic factor in type I as well as in type II EC although the overall prognosis differs significantly between the 2 types of EC. The prognostic impact of comorbidity varies with stage but not with type of EC.

Progesterone potentiates the growth inhibitory effects of calcitriol in endometrial cancer via suppression of CYP24A1

Here, we evaluated the expression of CYP24A1, a protein that inactivates vitamin D in tissues. CYP24A1 expression was increased in advanced-stage endometrial tumors compared to normal tissues. Similarly, endometrial cancer cells expressed higher levels of CYP24A1 than immortalized endometrial epithelial cells. RT-PCR and Western blotting were used to examine CYP24A1 mRNA and protein levels in endometrial cancer cells after 8, 24, 72, and 120 h of exposure to progesterone, progestin derivatives and calcitriol, either alone or in combination. Progestins inhibited calcitriol-induced expression of CYP24A1 and splice variant CYP24SV mRNA and protein in cancer cells. Furthermore, actinomycin D, but not cycloheximide, blocked calcitriol-induced CYP24A1 splicing. siRNA-induced knockdown of CYP24A1 expression sensitized endometrial cancer cells to calcitriol-induced growth inhibition. These data suggest that CYP24A1 overexpression reduces the antitumor effects of calcitriol in cancer cells and that progestins may be beneficial for maintaining calcitriol's anti-endometrial cancer activity.

Association of microRNA-200c expression levels with clinicopathological factors and prognosis in endometrioid endometrial cancer

INTRODUCTION

MicroRNAs (miRNAs) are regulators of gene expression, which play an important role in many critical cellular processes including apoptosis, proliferation and cell differentiation. Aberrant miRNA expression has been reported in a variety of human malignancies. Therefore, miRNAs may be potentially used as cancer biomarkers. miRNA-200c, which is a member of the miRNA-200 family, might play an essential role in tumor progression. The purpose of this study was to evaluate the prognostic and clinical significance of miRNA-200c in women with endometrioid endometrial cancer.

MATERIAL AND METHODS

Total RNA extraction from 90 archival formalin-fixed paraffin-embedded tissue samples of endometri-oid endometrial cancer and 10 normal endometrium samples was performed. After cDNA synthesis, real-time polymerase chain reaction was conducted and relative expression of miRNA-200c was assessed. Then, miRNA-200c expression levels were evaluated with regard to clinicopathological characteristics.

RESULTS

The expression levels of miRNA-200c were significantly increased in endometrioid endometrial cancer samples. Expression of miRNA-200c maintained at significantly higher levels in the early stage endometrioid endometrial cancer compared with more advanced stages. In the Kaplan-Meier analysis, lower levels of miRNA-200c expression were associated with inferior survival.

CONCLUSIONS

Expression levels of miRNA-200c might be associated with clinicopathological factors and survival in endometrioid endometrial cancer.

Evolving Roles of Histologic Evaluation and Molecular/Genomic Profiling in the Management of Endometrial Cancer

Endometrial cancers are the most common gynecologic malignancies. The staging of endometrial cancer has evolved from a clinical-based system to a comprehensive surgical-pathologic approach that allows for better risk stratification and treatment planning. Over the past few years, use of NCCN's sentinel lymph node (SLN) mapping algorithm for the surgical staging of endometrial cancer has gained significant acceptance and is now commonly applied in many practices. However, pathologic evaluation of prognostic factors is beset by challenges, including the reproducibility of histologic classification and FIGO's grading, as well as the questionable clinical significance of low-volume tumor in SLNs. With the revelation of major genomic classes of endometrial cancer comes the potential for improved, reproducible, and prognostically relevant classification schemes, which integrate traditional pathologic parameters with genomic findings, to aid in treatment decisions. Pathologic identification of new variants of endometrial cancer, such as undifferentiated carcinoma, continues to advance the phenotypic spectrum of these tumors, spurring genomic and functional studies to further characterize their mechanistic underpinnings and potentially reveal new avenues for treatment. In the era of precision medicine, pathologic assessment of biomarkers (eg, mismatch repair proteins) and recognition of phenotypes that are amenable to specific targeted therapies (such as POLE-mutated tumors) have become integral to the management of women with endometrial carcinoma.

Activin B promotes endometrial cancer cell migration by down-regulating E-cadherin via SMAD-independent MEK-ERK1/2-SNAIL signaling

High-risk type II endometrial cancers account for ~30% of cases but ~75% of deaths due, in part, to their tendency to metastasize. Histopathological studies of type II endometrial cancers (non-endometrioid, mostly serous) suggest overproduction of activin B and down-regulation of E-cadherin, both of which are associated with reduced survival. Our previous studies have shown that activin B increases the migration of type II endometrial cancer cell lines. However, little is known about the relationship between activin B signaling and E-cadherin in endometrial cancer. We now demonstrate that activin B treatment significantly decreases E-cadherin expression in both a time- and concentration-dependent manner in KLE and HEC-50 cell lines. Interestingly, these effects were not inhibited by knockdown of SMAD2, SMAD3 or SMAD4. Rather, the suppressive effects of activin B on E-cadherin were mediated by MEK-ERK1/2-induced production of the transcription factor SNAIL. Importantly, activin B-induced cell migration was inhibited by forced-expression of E-cadherin or pre-treatment with the activin/TGF-β type I receptor inhibitor SB431542 or the MEK inhibitor U0126. We have identified a novel SMAD-independent pathway linking enhanced activin B signaling to reduced E-cadherin expression and increased migration in type II endometrial cancer.

Mutation status coupled with RNA-sequencing data can efficiently identify important non-significantly mutated genes serving as diagnostic biomarkers of endometrial cancer

Background

Endometrial cancers (ECs) are one of the most common types of malignant tumor in females. Substantial efforts had been made to identify significantly mutated genes (SMGs) in ECs and use them as biomarkers for the classification of histological subtypes and the prediction of clinical outcomes. However, the impact of non-significantly mutated genes (non-SMGs), which may also play important roles in the prognosis of EC patients, has not been extensively studied. Therefore, it is essential for the discovery of biomarkers in ECs to further investigate the non-SMGs that were highly associated with clinical outcomes.

Results

For the 9681 non-SMGs reported by the mutation annotation pipeline, there were 1053, 1273 and 395 non-SMGs differentially expressed between the patient groups divided by the clinical endpoints of histological grade, histological type as well as the International Federation of Gynecology and Obstetrics (FIGO) stage of ECs, respectively. In the gene set enrichment analysis, the cancer-related pathways, namely neuroactive ligand-receptor interaction signaling pathway, cAMP signaling pathway and calcium signaling pathway, were significantly enriched with the differentially expressed non-SMGs for all the three endpoints. We further identified 23, 19 and 24 non-SMGs, which were highly associated with histological grade, histological type and FIGO stage, respectively, from the differentially expressed non-SMGs by using the variable combination population analysis (VCPA) approach and found that 69.6% (16/23), 78.9% (15/19) and 66.7% (16/24) of the identified non-SMGs had been previously reported to be correlated with cancers. In addition, the averaged areas under the receiver operating characteristic curve (AUCs) achieved by the predictive models with identified non-SMGs as predictors in predicting histological type, histological grade, and FIGO stage were 0.993, 0.961 and 0.832, respectively, which were superior to those achieved by the models with SMGs as features (averaged AUCs = 0.928, 0.864 and 0.535, resp.).

Conclusions

Besides the SMGs, the non-SMGs reported in the mutation annotation analysis may also involve the crucial genes that were highly associated with clinical outcomes. Combining the mutation status with the gene expression profiles can efficiently identify the cancer-related non-SMGs as predictors for cancer prognostic prediction and provide more supplemental candidates for the discovery of biomarkers.

Electronic supplementary material

The online version of this article (10.1186/s12859-017-1891-6) contains supplementary material, which is available to authorized users.

Dairy Products Intake and Endometrial Cancer Risk: A Meta-Analysis of Observational Studies

Observational studies have suggested inconsistent findings on the relationship between dairy products intake and endometrial cancer risk. This study aimed to conduct a meta-analysis to evaluate this correlation; moreover, databases including PubMed, ISI Web of Science, and Embase were screened for relevant studies up to 26 February 2017. The inverse variance weighting method and random effects models were used to calculate the overall OR (odds ratio) values and 95% confidence interval (CI). A total of 2 cohort study and 16 case-control studies were included in the current analysis. No significant association was observed between endometrial cancer risk and the intake of total dairy products, milk, or cheese for the highest versus the lowest exposure category (total dairy products (14 studies): OR 1.04, 95% CI: 0.97-1.11, I² = 73%, p = 0.000; milk (6 studies): 0.99, 95% CI: 0.89-1.10, I² = 0.0%, p = 0.43; cheese (5 studies): 0.89, 95% CI: 0.76-1.05, I² = 39%, p = 0.16). The only cohort study with a total of 456,513 participants reported a positive association of butter intake with endometrial cancer risk (OR = 1.14; 95% CI = 1.03-1.26, I² = 2.6%, p = 0.31). There was a significant negative association of dairy products intake and endometrial cancer risk among women with a higher body mass index (BMI) (5 studies, OR 0.66, 95% CI = 0.46-0.96, I² = 75.8%, p = 0.002). Stratifying the analyses by risk factors including BMI should be taken into account when exploring the association of dairy products intake with endometrial cancer risk. Further well-designed studies are needed.

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.

The role of pathology in the management of patients with endometrial carcinoma

Pathology plays a critical role in every step in the management of endometrial carcinoma patients. In this review, we describe the state of the art of pathological examination, including examination of endometrium biopsy; intra-operative evaluation with gross examination and frozen section; and grossing of hysterectomy specimen and its histological and immunohistochemistry study. The main pathologic findings in each step are described, as well as limitations and difficulties that may ensue. We highlight the important pathologic parameters that determine treatment options and prognosis of endometrial cancer patients.

Checkpoint inhibitors in endometrial cancer: preclinical rationale and clinical activity

CONTEXT

Treatment of advanced and recurrent endometrial cancer (EC) is still an unmet need for oncologists and gynecologic oncologists. The Cancer Genome Atlas Research Network (TCGA) recently provided a new genomic classification, dividing EC in four subgroups. Two types of EC, the polymerase epsilon (POLE)-ultra-mutated and the microsatellite instability-hyper-mutated (MSI-H), are characterized by a high mutation rate providing the rationale for a potential activity of checkpoint inhibitors.

MATERIALS AND METHODS

We analyzed all available evidence supporting the role of tumor microenvironment (TME) in EC development and the therapeutic implications offered by immune checkpoint inhibitors in this setting. We performed a review on Pubmed with Mesh keywords 'endometrial cancer' and the name of each checkpoint inhibitor discussed in the article. The same search was operated on clinicaltrial.gov to identify ongoing clinical trials exploring PD-1/PD-L1 and CTLA-4 axis in EC, particularly focusing on POLE-ultra-muted and MSI-H cancer types.

RESULTS

POLE-ultra-mutated and MSI-H ECs showed an active TME expressing high number of neo-antigens and an elevated amount of tumor infiltrating lymphocytes (TILs). Preliminary results from a phase-1 clinical trial (KEYNOTE-028) demonstrated antitumor activity of Pembrolizumab in EC. Moreover, both Pembrolizumab and Nivolumab reported durable clinical responses in POLE-ultra-mutated patients.

CONCLUSIONS

Immune checkpoint inhibitors are an attractive option in POLE-ultra-mutated and MSI-H ECs. Future investigations in these subgroups include combinations of checkpoints inhibitors with chemotherapy and small tyrosine kinase inhibitors (TKIs) to enhance a more robust intra-tumoral immune response.

Mixed endometrial carcinomas with a "low-grade serous"-like component: a clinicopathologic, immunohistochemical, and molecular genetic study

Recently, we reported 2 mixed endometrioid endometrial carcinomas with a "low-grade serous"-like component, which does not fit into any of the 4 molecular groups described by The Cancer Genome Atlas. To understand the nature of these tumors, we have done an immunohistochemical and molecular genetic study of these 2 cases and added a third case. Immunoreactivity for p53, ER, Ki67, WT1, MLH1, PMS2, MSH2, and MSH6 was assessed. Targeted next-generation sequencing for somatic mutations, including genes commonly implicated in carcinogenesis including TP53, KRAS, and PIK3CA, and Sanger sequencing for PTEN and POLE were also performed. All patients were nulliparous and had morbid obesity. Their tumors showed a micropapillary component that resembled that of ovarian low-grade serous carcinoma and merged with villoglandular endometrioid carcinoma. The invasive tumor glands exhibited a microcystic, elongated, or fragmented pattern and contained psammoma bodies. Two tumors showed aberrant p53 expression, and all 3 were positive for ER. All showed KRAS mutations, and TP53 mutations were found in 2 cases. One patient developed peritoneal carcinomatosis, one patient is alive with disease, and another died of a brain tumor. The third patient, whose tumor was confined to the uterus (stage IA), is alive without evidence of disease, but she has been followed for only 6 months. Mixed endometrial carcinomas with a "low-grade" serous-like component exhibit a morphologic spectrum of endometrioid and serous differentiation with microcystic, elongated, or fragmented features; ER expression; KRAS and TP53 mutations; and aggressive behavior.

TP53 Mutational Spectrum in Endometrioid and Serous Endometrial Cancers

Endometrial carcinomas (ECs) are heterogeneous at the genetic level. Although TP53 mutations are highly recurrent in serous endometrial carcinomas (SECs), these are also present in a subset of endometrioid endometrial carcinomas (EECs). Here, we sought to define the frequency, pattern, distribution, and type of TP53 somatic mutations in ECs by performing a reanalysis of the publicly available data from The Cancer Genome Atlas (TCGA). A total of 228 EECs (n=186) and SECs (n=42) from the TCGA data set, for which an integrated genomic characterization was performed, were interrogated for the presence and type of TP53 mutations, and for mutations in genes frequently mutated in ECs. TP53 mutations were found in 15% of EECs and 88% of SECs, and in 91% of copy-number-high and 35% of polymerase (DNA directed), epsilon, catalytic subunit (POLE) integrative genomic subtypes. In addition to differences in prevalence, variations in the type and pattern of TP53 mutations were observed between histologic types and between integrative genomic subtypes. TP53 hotspot mutations were significantly more frequently found in SECs (46%) than in EECs (15%). TP53-mutant EECs significantly more frequently harbored a co-occurring PTEN mutation than TP53-mutant SECs. Finally, a subset of TP53-mutant ECs (22%) was found to harbor frameshift or nonsense mutations. Given that nonsense and frameshift TP53 mutations result in distinct p53 immunohistochemical results that require careful interpretation, and that EECs and SECs display different patterns, types, and distributions of TP53 mutations, the use of the TP53/p53 status alone for the differential diagnosis of EECs and SECs may not be sufficient.

Hypermethylation of WIF1 and its inhibitory role in the tumor growth of endometrial adenocarcinoma

Endometrial carcinoma is the most common malignancy of the female genital tract and is the fourth most common malignancy among women worldwide. Endometrial adenocarcinoma (EAC) accounts for ~80% of endometrial carcinoma cases. Numerous critical genetic events have been determined to serve an essential role in EAC progression; however, the precise molecular mechanisms underlying EAC progression remain unclear. Pyrosequencing and methylation-specific PCR were used to detect the methylation status of Wnt inhibitory factor 1 (WIF1). Immunohistochemistry and western blot were used to detect the expression of WIF1, Wnt family member 1 and other related pathways. The anticancer role of WIF1 in EAC was investigated in vitro and in vivo. Two of the three EAC cases exhibited significantly high methylation in five CpG sites, and the WIF1 methylation rate in EAC and endometrial tissues was 43.4 and 8%, respectively (P<0.05). The kappa consistency coefficient was −0.369 between methylation and mRNA expression (P<0.05) and WIF1 expression levels were significantly downregulated in EAC tissues compared with non-tumorous tissues (P<0.01). The 5-year overall survival rates were significantly lower for patients with tumors that negatively expressed WIF1 when compared with the 77.9% exhibited by those with positive WIF1 expression. Furthermore, the proliferation rate of KLE cells was significantly reduced following 5-aza-20-deoxycytidine treatment or WIF1 overexpression in vitro and in vivo, which may be associated with downregulated c-Myc and phosphorylated-extracellular signal-regulated kinase expression. These results demonstrated the important role of WIF1 in EAC tumorigenesis, and suggested that WIF1 may be a potential drug target in EAC treatment.

Inhibition of PI3K-AKT-mTOR pathway sensitizes endometrial cancer cell lines to PARP inhibitors

BACKGROUND

Phosphatase and Tensin homolog (PTEN) is a tumor suppressor gene. Loss of its function is the most frequent genetic alteration in endometrioid endometrial cancers (70-80%) and high grade tumors (90%). We assessed the sensitivity of endometrial cancer cell lines to PARP inhibitors (olaparib and BMN-673) and a PI3K inhibitor (BKM-120), alone or in combination, in the context of their PTEN mutation status. We also highlighted a direct pathway linking PTEN to DNA repair.

METHODS

Using endometrial cancer cellular models with known PTEN status, we evaluated their homologous recombination (HR) functionality by RAD51 foci formation assay. The 50% Inhibitory concentration (IC50) of PI3K and PARP inhibitors in these cells was assessed, and western blotting was performed to determine the expression of proteins involved in the PI3K/mTOR pathway. Moreover, we explored the interaction between RAD51 and PI3K/mTOR by immunofluorescence. Next, the combination effect of PI3K and PARP inhibitors on cell proliferation was evaluated by a clonogenic assay.

RESULTS

Cells with mutated PTEN showed over-activation of the PI3K/mTOR pathway. These cells were more sensitive to PARP inhibition compared to PTEN wild-type cells. In addition, PI3K inhibitor treatment reduced RAD51 foci formation in PTEN mutated cells, and sensitized these cells to PARP inhibitor.

CONCLUSION

Targeting both PARP and PI3K might lead to improved personalized therapeutic approaches in endometrial cancer patients with PTEN mutations. Understanding the complex interaction of PTEN mutations with DNA repair in endometrial cancer will help to better select patients that are likely to respond to some of the new and costly targeted therapies.

The genetic landscape of endometrial clear cell carcinomas

Clear cell carcinoma of the endometrium is a rare type of endometrial cancer that is generally associated with an aggressive clinical behaviour. Here, we sought to define the repertoire of somatic genetic alterations in endometrial clear cell carcinomas (ECCs), and whether ECCs could be classified into the molecular subtypes described for endometrial endometrioid and serous carcinomas. We performed a rigorous histopathological review, immunohistochemical analysis and massively parallel sequencing targeting 300 cancer-related genes of 32 pure ECCs. Eleven (34%), seven (22%) and six (19%) ECCs showed abnormal expression patterns for p53, ARID1A, and at least one DNA mismatch repair (MMR) protein, respectively. Targeted sequencing data were obtained from 30 of the 32 ECCs included in this study, and these revealed that two ECCs (7%) were ultramutated and harboured mutations affecting the exonuclease domain of POLE. In POLE wild-type ECCs, TP53 (46%), PIK3CA (36%), PPP2R1A (36%), FBXW7 (25%), ARID1A (21%), PIK3R1 (18%) and SPOP (18%) were the genes most commonly affected by mutations; 18% and 11% harboured CCNE1 and ERBB2 amplifications, respectively, and 11% showed DAXX homozygous deletions. ECCs less frequently harboured mutations affecting CTNNB1 and PTEN but more frequently harboured PPP2R1A and TP53 mutations than non-POLE endometrioid carcinomas from The Cancer Genome Atlas (TCGA). Compared to endometrial serous carcinomas (TCGA), ECCs less frequently harboured TP53 mutations. When a surrogate model for the molecular-based TCGA classification was used, all molecular subtypes previously identified in endometrial endometrioid and serous carcinomas were present in the ECCs studied, including POLE, MMR-deficient, copy-number high (serous-like)/p53 abnormal, and copy-number low (endometrioid)/p53 wild-type, which were significantly associated with disease-free survival in univariate analysis. These findings demonstrate that ECCs constitute a histologically and genetically heterogeneous group of tumours with varying outcomes. Furthermore, our data suggest that the classification of ECCs as being generally 'high-grade' or 'type II' tumours may not be warranted. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Hormonal and Growth Regulation of Epithelial and Stromal Cells From the Normal and Malignant Endometrium by Pigment Epithelium-Derived Factor

We discovered that pigment epithelium-derived factor (PEDF)-null mice have endometrial hyperplasia, the precursor to human type I endometrial cancer (ECA), which is etiologically linked to unopposed estrogen (E2), suggesting that this potent antiangiogenic factor might contribute to dysregulated growth and the development of type I ECA. Treatment of both ECA cell lines and primary ECA cells with recombinant PEDF dose dependently decreased cellular proliferation via an autocrine mechanism by blocking cells in G1 and G2 phases of the cell cycle. Consistent with the known opposing effects of E2 and progesterone (Pg) on endometrial proliferation, Pg increases PEDF protein synthesis and release, whereas E2 has the converse effect. Using PEDF luciferase promoter constructs containing two Pg and one E2 response elements, E2 reduced and Pg increased promoter activity due to distal response elements. Furthermore, E2 decreases and Pg increases PEDF secretion into conditioned media (CM) by both normal endometrial stromal fibroblasts (ESFs) and cancer-associated fibroblasts (CAFs), but only CM from ESFs mediated growth-inhibitory activity of primary endometrial epithelial cells (EECs). In addition, in cocultures with primary EECs, Pg-induced growth inhibition is mediated by ESFs, but not CAFs. This is consistent with reduced levels of Pg receptors on CAFs surrounding human malignant glands in vivo. Taken together, the data suggest that PEDF is a hormone-regulated negative autocrine mediator of endometrial proliferation, and that paracrine growth inhibition by soluble factors, possibly PEDF, released by ESFs in response to Pg, but not CAFs, exemplifies a tumor microenvironment that contributes to the pathogenesis of ECA.

Hypomethylation associated enhanced transcription of trefoil factor-3 mediates tamoxifen-stimulated oncogenicity of ER+ endometrial carcinoma cells

Tamoxifen (TAM) is widely used as an adjuvant therapy for women with breast cancer (BC). However, TAM possesses partial oestrogenic activity in the uterus and its use has been associated with an increased incidence of endometrial carcinoma (EC). The molecular mechanism for these observations is not well understood. Herein, we demonstrated that forced expression of Trefoil factor 3 (TFF3), in oestrogen receptor-positive (ER+) EC cells significantly increased cell cycle progression, cell survival, anchorage-independent growth, invasiveness and tumour growth in xenograft models. Clinically, elevated TFF3 protein expression was observed in EC compared with normal endometrial tissue, and its increased expression in EC was significantly associated with myometrial invasion. TAM exposure increased expression of TFF3 in ER+ EC cells and its elevated expression resulted in increased oncogenicity and invasiveness. TAM-stimulated expression of TFF3 in EC cells was associated with hypomethylation of the TFF3 promoter sequence and c-JUN/SP1-dependent transcriptional activation. In addition, small interfering (si) RNA-mediated depletion or polyclonal antibody inhibition of TFF3 significantly abrogated oncogenicity and invasiveness in EC cells consequent to TAM induction or forced expression of TFF3. Hence, TAM-stimulated upregulation of TFF3 in EC cells was critical in promoting EC progression associated with TAM treatment. Importantly, inhibition of TFF3 function might be an attractive molecular modality to abrogate the stimulatory effects of TAM on endometrial tissue and to limit the progression of EC.

Molecular Pathology: Predictive, Prognostic, and Diagnostic Markers in Uterine Tumors

This article focuses on the diagnostic, prognostic, and predictive molecular biomarkers in uterine malignancies, in the context of morphologic diagnoses. The histologic classification of endometrial carcinomas is reviewed first, followed by the description and molecular classification of endometrial epithelial malignancies in the context of histologic classification. Taken together, the molecular and histologic classifications help clinicians to approach troublesome areas encountered in clinical practice and evaluate the utility of molecular alterations in the diagnosis and subclassification of endometrial carcinomas. Putative prognostic markers are reviewed. The use of molecular alterations and surrogate immunohistochemistry as prognostic and predictive markers is also discussed.

New use of microsatellite instability analysis in endometrial cancer

The increasing incidence of obesity and diabetes due to changes in diet, earlier menarche, delayed menopause, late marriage, and declining birth rate have resulted in an increase in the number of endometrial cancer cases over the last few decades. Although surgical therapy is sufficient for early endometrial cancer, there is no effective therapy for patients with advanced and recurrent endometrial cancer. The oncogenic mechanism of endometrial cancer involves microsatellite instability (MSI) caused by dysfunction of DNA mismatch repair genes in 30% of patients. Immune checkpoint inhibitors, including anti-programmed death (PD)-1 and anti-PD-ligand 1 antibodies, are of interest as novel anticancer drugs; however, these drugs are currently expensive, and there is a need to select patients who will benefit from their use. The use of MSI analysis as a predictive biomarker for the therapeutic efficacy of these drugs may be useful for reducing the costs of drug therapy.

Mixed and Ambiguous Endometrial Carcinomas: A Heterogenous Group of Tumors With Different Clinicopathologic and Molecular Genetic Features

Besides endometrioid, serous, and clear cell carcinomas, there are endometrial carcinomas exhibiting mixed and ambiguous morphologic features. We have analyzed the immunophenotype (p53, p16, β-catenin, ER, HNF-1B, MLH1, and Ki-67) and mutational status (PTEN, KRAS, PIK3CA, and POLE) of 7 mixed carcinomas and 13 ambiguous carcinomas, all of them classified initially as mixed carcinomas. Only 2 of the 7 (28%) mixed carcinomas showed different immunophenotypes in different components. All but 2 tumors (5/7, 71%) overexpressed p53 and p16 and were negative for ER. Both carcinomas (2/7, 28%) showed a prominent micropapillary component that resembled an ovarian low-grade serous carcinoma and merged with villoglandular endometrioid carcinoma. The ambiguous carcinomas exhibited glandular architecture, high nuclear grade, and overlapping features of endometrioid and serous carcinomas. All tumors overexpressed p53 and p16, and the majority of cases (12/13, 92%) were negative for ER. KRAS mutations were identified in 3 of 7 (42%) mixed carcinomas, including the 2 cases with a "low-grade" serous-like component. PIK3CA mutations occurred in 2 (2/13, 15%) ambiguous carcinomas and PTEN mutations in 1 (1/7, 14%) mixed and 1 (1/13, 8%) ambiguous carcinoma. POLE exonuclease domain mutations were encountered in a case of mixed undifferentiated and well-differentiated (dedifferentiated) carcinoma. Two of the 7 (29%) mixed endometrial carcinomas and 5 of the 13 (38%) ambiguous carcinomas had extended beyond the pelvis (stages III and IV). Two of the 7 (29%) patients with mixed endometrial carcinoma and 6 of 12 (50%) patients with ambiguous endometrial carcinoma were alive with disease or had died of tumor. Our results show that, biologically, many so-called mixed carcinomas represent serous carcinomas with ambiguous morphology. Our series include 2 true mixed endometrial carcinomas with a "low-grade serous"-like component, microcystic, elongated, or fragmented features, KRAS mutations, and aggressive behavior.

STAR and AKR1B10 are down-regulated in high-grade endometrial cancer

Endometrial cancer is the most frequent gynecological malignancy in the developed world. The majority of cases are estrogen dependent, and are associated with diminished protective effects of progesterone. Endometrial cancer is also related to enhanced inflammation and decreased differentiation. In our previous studies, we examined the expression of genes involved in estrogen and progesterone actions in inflammation and tumor differentiation, in tissue samples from endometrial cancer and adjacent control endometrium. The aims of the current study were to examine correlations between gene expression and several demographic characteristics, and to evaluate changes in gene expression with regard to histopathological and clinical characteristics of 51 patients. We studied correlations and differences in expression of 38 genes involved in five pathophysiological processes: (i) estrogen-stimulated proliferation; (ii) estrogen-dependent carcinogenesis; (iii) diminished biosynthesis of progesterone: (iv) enhanced formation of progesterone metabolites; and (v) increased inflammation and decreased differentiation. Spearman correlation coefficient analysis shows that expression of PAQR7 correlates with age, expression of SRD5A1, AKR1B1 and AKR1B10 correlate with body mass, while expression of SRD5A1 and AKR1B10 correlate with body mass index. When patients with endometrial cancer were stratified based on menopausal status, histological grade, myometrial invasion, lymphovascular invasion, and FIGO stage, Mann-Whitney U tests revealed significantly decreased expression of STAR (4.4-fold; adjusted p=0.009) and AKR1B10 (9-fold; adjusted p=0.003) in high grade versus low grade tumors. Lower levels of STAR might lead to decreased de-novo steroid hormone synthesis and tumor differentiation, and lower levels of AKR1B10 to diminished elimination of toxic electrophilic carbonyl compounds in high-grade endometrial cancer. These data thus reveal the potential of STAR and AKR1B10 as prognostic biomarkers, which calls for further validation at the protein level.

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.

Identification of a gene expression profile associated with the regulation of angiogenesis in endometrial cancer

The publication of the human genome sequence provided direction in the search for novel diagnostic and therapeutic methods for the treatment of human diseases. The aim of the present study was to investigate the hypothesis that the expression profile of genes involved in the regulation of angiogenesis may be a marker in endometrial cancer that facilitates the diagnosis and prognosis of patients, as well as the identification of novel therapeutic targets. The current study included 36 patients with grade (G) 1 to 3 endometrial cancer, and a control group of patients consisting of females that qualified for the removal of the uterus. Out of these, 28 samples (control, 3; G1, 7; G2, 12; and G3, 6) were selected for microarray analysis. Molecular analysis of the endometrial samples involved the extraction of total RNA, purification of the obtained extracts and subsequent analysis of the gene expression profiles using an oligonucleotide microarray technique (GeneChip^® Human Genome U133A plates). The results indicated that the mRNA expression profile of genes involved in the regulation of angiogenesis varies depending on the degree of histological differentiation of endometrial adenocarcinoma. Similar results were obtained from descriptive statistics characterizing the expression profile of 691 mRNAs associated with the regulation of angiogenesis in the groups of patients with endometrial adenocarcinoma. In addition, the results of the present study indicated that neuropilin2 (NRP2) may serve an important role in the activity of endothelial cells, and may affect vascular endothelial growth factor, and potentially plexins and integrins via regulation of their functions. An understanding of how these proteins interact remains to be determined; however, elucidating these interactions may provide an explanation for the mechanisms underlying angiogenesis. In conclusion, the results of the present study suggest that NRP2 may be a valuable target for investigation in future pharmacological studies involving angiogenesis in endometrial cancer.

The Importance of Steroid Uptake and Intracrine Action in Endometrial and Ovarian Cancers

Endometrial and ovarian cancers predominately affect women after menopause, and are more frequently observed in developed countries. These are considered to be hormone-dependent cancers, as steroid hormones, and estrogens in particular, have roles in their onset and progression. After the production of estrogens in the ovary has ceased, estrogen synthesis occurs in peripheral tissues. This depends on the cellular uptake of estrone-sulfate and dehydroepiandrosterone-sulfate, as the most important steroid precursors in the plasma of postmenopausal women. The uptake through transporter proteins, such as those of the organic anion-transporting polypeptide (OATP) and organic anion-transporter (OAT) families, is followed by the synthesis and action of estradiol E2. Here, we provide an overview of the current understanding of this intracrine action of steroid hormones, which depends on the availability of the steroid precursors and transmembrane transporters for precursor uptake, along with the enzymes for the synthesis of E2. The data is also provided relating to the selected transmembrane transporters from the OATP, OAT, SLC51, and ABC-transporter families, and the enzymes involved in the E2-generating pathways in cancers of the endometrium and ovary. Finally, we discuss these transporters and enzymes as potential drug targets.

Hypoxia- and acidosis-driven aberrations of secreted microRNAs in endometrial cancer in vitro

Due to their post-transcriptional regulatory impact on gene expression, microRNAs (miRNA, miRs) influence decisively cellular processes of differentiation, proliferation and apoptosis. In oncogenic pathways various miRNAs exert either oncogenic or tumor suppressor activities in a stage-specific manner. Dysregulation of miRNA expression pattern has been associated with several human cancers including endometrial cancer (EC). In the present study, expression profile alterations of EC associated secreted miRNAs were determined under the microenvironmental stress situations hypoxia and acidosis occurring in tumor progression and metastasis. The potential influence of hypoxia and acidosis vs. control conditions on the expression levels of 24 EC-relevant miRNA types was quantitatively accessed via real-time PCR in three established EC in vitro models. Expression data were analyzed statistically. In vitro application of hypoxia resulted in downregulation of miR-15a, miR-20a, miR-20b and miR-128-1 in Ishikawa cells (type I EC) and upregulation of miR-21 in EFE-184 cells (type I EC). Acidosis triggered upregulation of tumor promoting miR-125b in AN3-CA cell (type II EC), whereas in Ishikawa cells (type I EC) miRNAs with tumor suppressive function were found altered in divergent directions, both up- (let-7a) and down- (miR-22) regulated. Our current findings emphasize the functional importance of secreted miRNAs in the immediate response of EC cells to exogenic stress situations such as the typical tumor epiphenomena hypoxia and acidosis. Focusing on the specific potential of secreted, thus circulating miRNA molecules, alterations in expression levels not only influence intracellular gene expression and signaling cascades, but also transfer the induction of (tumor)biological cellular changes to adjacent cells.

Sox2-dependent inhibition of p21 is associated with poor prognosis of endometrial cancer

Sex‐determining region Y‐box 2 (SOX2) is an essential factor involved in the self‐renewal and pluripotency of embryonic stem cells and has functions in cell survival and progression in many types of cancers. Here, we found that several endometrial cancer cell lines expressed SOX2, which was required for cell growth. Additionally, SOX2 overexpression regulated the expression of cyclin‐dependent kinase inhibitor 1A (CDKN1A), and SOX2 specifically bound to p21 promoter DNA in endometrial cancer cell lines expressing SOX2. Expressions of SOX2 in endometrial cancer patients were significantly correlated with histological grade and poor prognosis. Moreover, low p21 together with high SOX2 expressions in advanced endometrial cancer patients were associated with the most unfavorable outcomes of patients. These results indicated that simultaneous measurement of SOX2 and p21 expression in endometrial cancer patients may be a useful biomarker for patient prognosis.

Does hysteroscopy worsen prognosis in women with type II endometrial carcinoma?

Background

Prior studies evaluating the impact of hysteroscopy on outcomes in endometrial cancer have predominantly evaluated type I tumors. We sought to evaluate whether hysteroscopy worsens prognosis in type II endometrial cancer.

Methods

A retrospective cohort analysis of 140 patients from two institutions with type II endometrial cancer was performed. Women who underwent either diagnostic hysteroscopy (HSC) or dilation and curettage (D&C) for cancer diagnosis from June 2001 until June 2010 were included. The clinical and pathologic characteristics, including peritoneal cytology results were reviewed. The primary endpoint was disease-specific survival (DSS). The exposure of interest was hysteroscopy. Survival curves were projected using the Kaplan-Meier method and compared using the log-rank test.

Results

There was no difference in age, histology, stage, depth of myometrial invasion, adnexal involvement, or nodal metastasis between HSC and D&C patients. Positive cytology was found in 16/54 (30%) patients following HSC and in 10/86 (12%) following D&C (p = 0.008). Fourteen patients with stage I and II disease had positive peritoneal cytology, with 11/40 (27.5%) patients in the HSC group and 3/59 (5%) patients in the D&C group(p = 0.002). Median DSS was clinically different for the HSC and D&C groups, but statistical significance was not reached (53 versus 63.5 months, p = 0.34). For stage I and II patients, 18/99 (18%) were dead of EC, with a median DSS of 60 months for HSC and 71 months for D&C (p = 0.82). Overall 46 (33%) patients developed a recurrence, with 18/54 (33%) in the HSC group compared to 28/86 (32%) in the D&C group (p = 0.92). There was no difference in recurrence location between groups.

Conclusions

Diagnostic hysteroscopy significantly increased the rate of positive peritoneal cytology at the time of surgical staging in this cohort of patients with type II EC. However, we were unable to detect a difference in prognosis as measured by DSS.

TGFβ1 induces endometrial cancer cell adhesion and migration by up-regulating integrin αvβ3 via SMAD-independent MEK-ERK1/2 signaling

Endometrial cancer is the most common, and second most lethal, gynecological malignancy, and its rates of incidence and death are growing. This is likely attributable to increased numbers of high-risk type II endometrial cancers which account for ~30% of cases but ~75% of deaths due to their aggressive and metastatic behaviour. Histopathological and in vitro functional studies suggest that aberrant TGFβ1 signaling may contribute to endometrial cancer development and the acquisition of invasive/metastatic characteristics. However, little is known about the cellular and molecular mechanisms of TGFβ1 in high-risk endometrial cancers. In the present study, we examined the roles and mechanisms of TGFβ1 on cell adhesion and motility in type II endometrial cancer cell lines, KLE and HEC-1B. We show that treatment with TGFβ1 increases cell adhesion to vitronectin and transwell cell migration. We also demonstrate that TGFβ1 treatment increases integrin β3 and αv mRNA and protein levels via SMAD-independent MEK-ERK1/2 signaling. Importantly, siRNA depletion or antibody-mediated blocking of integrin αvβ3 reversed the effects of TGFβ1 on cell adhesion and migration. Our results suggest that TGFβ1-MEK-ERK1/2-integrin αvβ3 signaling could contribute to the invasive behaviour of high-risk endometrial cancer by promoting cell adhesion and migration.

Survival of Patients with Serous Uterine Carcinoma Undergoing Sentinel Lymph Node Mapping

OBJECTIVE

The aim of this study was to determine progression-free survival (PFS) in patients with serous uterine carcinoma undergoing sentinel lymph node (SLN) mapping compared with patients undergoing standard lymphadenectomy.

METHODS

We retrospectively reviewed all uterine cancer patients treated at our institution from 2005 to 2015. Patients were separated into two cohorts: those who underwent SLN mapping at the time of staging (SLN) and those who underwent routine lymphadenectomy (the non-SLN group). SLN mapping was performed according to institutional protocol, incorporating a surgical algorithm and pathologic ultrastaging.

RESULTS

Overall, 248 patients were identified-153 SLN mappings and 95 routine lymphadenectomies (pelvic and/or paraaortic lymph node dissection). No significant difference in age or body mass index was observed between the groups (p = 0.08 and p = 0.9, respectively). Minimally invasive surgery was utilized in 117/153 (77%) SLN patients and 30/95 (32%) non-SLN patients (p = <0.001). Stage distribution for the SLN and non-SLN cohorts demonstrated 106/153 (69%) and 59/95 (62%) patients with stage I/II disease, respectively, and 47/153 (31%) and 36/95 (38%) patients with stage III/IV disease, respectively (p = 0.3). The median number of nodes removed was 12 (range, 1-50) in the SLN cohort versus 21 (range, 1-75) in the non-SLN cohort (p = <0.001). Adjuvant chemotherapy alone or with radiation therapy was administered in 122/153 (80%) SLN patients and 79/95 (83%) non-SLN patients; radiotherapy alone was administered in 12/153 (8%) SLN patients and 7/95 (7%) non-SLN patients (p = 0.8). At a median follow-up of 40 months, the 2-year PFS rates were 77% (95% confidence interval [CI], 68-83%) in the SLN group and 71% (95% CI, 61-79%) in the non-SLN group (p = 0.3).

CONCLUSIONS

Incorporation of the SLN mapping algorithm into the staging of uterine serous cancer is feasible and does not appear to compromise prognosis. PFS in patients with uterine serous carcinoma undergoing SLN mapping, followed by adjuvant therapy, was similar to PFS in patients undergoing standard lymphadenectomy and adjuvant therapy.

New concepts for an old problem: the diagnosis of endometrial hyperplasia

BACKGROUND

Endometrial hyperplasia (EH) is a uterine pathology representing a spectrum of morphological endometrial alterations. It is predominantly characterized by an increase in the endometrial gland-to-stroma ratio when compared to normal proliferative endometrium. The clinical significance of EH lies in the associated risk of progression to endometrioid endometrial cancer (EC) and 'atypical' forms of EH are regarded as premalignant lesions. Traditional histopathological classification systems for EH exhibit wide and varying degrees of diagnostic reproducibility and, as a consequence, standardized patient management can be challenging.

OBJECTIVE AND RATIONALE

EC is the most common gynaecological malignancy in developed countries. The incidence of EC is rising, with alarming increases described in the 40-44-year-old age group. This review appraises the current EH classification systems used to stratify women at risk of malignant progression to EC. In addition, we summarize the evidence base regarding the use of immunohistochemical biomarkers for EH and discuss an emerging role for genomic analysis.

SEARCH METHODS

PubMed, Medline and the Cochrane Database were searched for original peer-reviewed primary and review articles, from January 2000 to January 2016. The following search terms were used: 'endometrial hyperplasia', 'endometrial intraepithelial neoplasia', 'atypical hyperplasia', 'complex atypical hyperplasia', 'biomarker', 'immunohistochemistry', 'progression', 'genomic', 'classification' and 'stratification'.

OUTCOMES

Recent changes to EH classification reflect our current understanding of the genesis of endometrioid ECs. The concept of endometrial intraepithelial neoplasia (EIN) as a mutationally activated, monoclonal pre-malignancy represents a fundamental shift from the previously held notion that unopposed oestrogenic stimulation causes ever-increasing hyperplastic proliferation, with accumulating cytological atypia that imperceptibly leads to the development of endometrioid EC. Our review highlights several key biomarker candidates that have been described as both diagnostic tools for EH and markers of progression to EC. We propose that, moving forwards, a 'panel' approach of combinations of the immunohistochemical biomarkers described in this review may be more informative since no single candidate can currently fill the entire role.

WIDER IMPLICATIONS

EC has historically been considered a predominantly postmenopausal disease. Owing in part to the current unprecedented rates of obesity, we are starting to see signs of a shift towards a rising incidence of EC amongst pre- and peri-menopausal woman. This creates unique challenges both diagnostically and therapeutically. Furthering our understanding of the premalignant stages of EC development will allow us to pursue earlier diagnosis and facilitate appropriate stratification of women at risk of developing EC, permitting timely and appropriate therapeutic interventions.

Recent Developments in Surgical Pathology of the Uterine Corpus

There have been several updates recently on the classification of uterine tumors. Endometrial carcinomas have traditionally been divided into 2 types, but some are difficult to classify and do not fit readily into either of the currently recognized categories. The Cancer Genome Atlas Research Network has recently defined 4 new categories of endometrial cancer on the basis of mutational spectra, copy number alteration, and microsatellite instability, which might provide independent prognostic information beyond established risk factors. The Society of Gynecologic Oncology, moreover, now recommends systematic screening of every patient with endometrial cancer for Lynch syndrome. The new definition of high-grade endometrial stromal sarcoma disregards the number of mitotic figures as a primary diagnostic criterion and instead specifies moderate atypia still resembling stromal origin but lacking the pleomorphism of undifferentiated uterine sarcoma; these tumors also harbor a JAZF1-SUZ12 gene rearrangement. Mitotic count, atypia, and coagulative necrosis are the main histologic criteria that define leiomyosarcoma. Determining the type of necrosis can be very challenging in patients receiving various treatment modalities for symptomatic fibroids before myomectomy, since key histologic features of ischemic-type necrosis are often absent. Ancillary stains including p16, p53, MIB-1, trichrome, and reticulin may be helpful in tumors harboring necrosis that is difficult to classify. Minimally invasive gynecologic surgeries have introduced histologic artifacts that complicate the diagnosis. It is essential to recognize these as procedure-related artifacts to avoid upstaging tumors and triggering unnecessary adjuvant treatment.

Differential Expression and Clinical Significance of DNA Methyltransferase 3B (DNMT3B), Phosphatase and Tensin Homolog (PTEN) and Human MutL Homologs 1 (hMLH1) in Endometrial Carcinomas

BACKGROUND The aim of this study was to investigate the expression and the clinicopathologic significance of DNA methyltransferase 3B (DNMT3B), phosphatase and tensin homolog (PTEN) and human MutL homologs 1 (hMLH1) in endometrial carcinomas between Han and Uygur women in Xinjiang. MATERIAL AND METHODS The expression of DNMT3B, PTEN, and hMLH1 in endometrial carcinomas were assessed by immunohistochemistry, followed by an analysis of their relationship to clinical-pathological features and prognosis. RESULTS There were a 61.7% (95/154) overexpression of DNMT3B, 50.0% (77/154) loss of PTEN expression and 18.2% (28/154) loss of hMLH1 expression. The expression of DNMT3B and PTEN in endometrial carcinomas was statistically significantly different between Uygur women and Han women (p=0.001, p=0.010, respectively). DNMT3B expression was statistically significant based on the grade of endometrial carcinomas (p=0.031). PTEN loss was statistically significant between endometrioid carcinomas (ECs) and non endometrioid carcinomas (NECs) (p=0.040). DNMT3B expression was statistically significant in different myometrial invasion groups in Uygur women (p=0.010). Furthermore, the correlation of DNMT3B and PTEN expression was significant in endometrial carcinomas (p=0.021). PTEN expression was statistically significant in the overall survival (OS) rate of women with endometrial cancers (p=0.041). CONCLUSIONS Our findings suggest that PTEN and DNMT3B possess common regulation features as well as certain ethnic differences in expression between Han women and Uygur women. An interaction may exist in the pathogenesis of endometrial carcinoma. DNMT3B was expressed differently in cases of myometrial invasion and PTEN was associated with OS, which suggested that these molecular markers may be useful in the evaluation of the biological behavior of endometrial carcinomas and may be useful indicators of prognosis in women with endometrial carcinomas.

MDH2 Stimulated by Estrogen-GPR30 Pathway Down-Regulated PTEN Expression Promoting the Proliferation and Invasion of Cells in Endometrial Cancer

PURPOSE: The relationship between endometrial carcinoma and cellular metabolism is unknown. In endometrial cancer, mutation rate of PTEN has been reported very high. Malate dehydrogenase 2 (MDH2) is one of the isoforms of malate dehydrogenase, which is involved in citric acid cycle in mitochondria. Our study aimed to investigate the role MDH2 played in PTEN-regulated endometrial carcinoma. METHODS: To reveal the expression of MDH2 and the co-localization of PTEN and MDH2, immunohistochemistry and immunofluorescent staining were used. Western blot, Real-time PCR, RNA interference and overexpression plasmid DNA transfection were performed to investigate the relationship between PTEN and MDH2 as well as the impact of E2 on the expression of PTEN and MDH2, while CCK8, transwell and flow cytometric analysis were carried out to evaluate the proliferation, migration and invasion and apoptosis of endometrial carcinoma cell lines. RESULTS: Our results demonstrated that as a metabolism related enzyme, MDH2 was overexpressed in endometrial carcinoma tissues and related to the grade of the cancer (P = .038). Western blot, Real-time PCR and immunofluorescent staining revealed MDH2 inhibited the expression of PTEN and was co-localized with PTEN in the cytoplasm of endometrial carcinoma. Proliferation, transwell and apoptosis assay suggested that MDH2 enhanced the proliferation, migration and invasion but inhibited the apoptosis of endometrial cancer cell line through suppressing PTEN. Furthermore, E2 inhibited the expression level of PTEN but enhanced MDH2 via GPR30. CONCLUSIONS: Our study demonstrated that MDH2, stimulated by estrogen, was involved in the development of PTEN-regulated endometrial carcinoma through GPR30-related pathway.