Reproducibility of histological cell type in high-grade endometrial carcinoma

Preoperative MRI and immunohistochemical examination for the prediction of high-risk endometrial cancer

Background

Magnetic resonance imaging (MRI) and immunohistochemical (IHC) examination provides useful information for the risk stratification of endometrial cancer (EC). However, the use of the combination of MRI and IHC for the prediction of high-risk EC is controversial. The aim of this study was to evaluate the value of preoperative MRI and IHC examination in prediction of patients with high-risk EC.

Methods

This retrospective case-control study was conducted from January 1, 2018 to May 1, 2021 at two hospitals. A primary cohort (n=102) comprised patients with histologically confirmed EC in one hospital between January 1, 2018 and May 31, 2020. An additional external cohort (n=35) comprising patients with histologically confirmed EC in a different hospital from January 1, 2020 to May 1, 2021 was included for validation. Imaging features including tumor size, tumor margin, relative T2 value, tumor signal intensity on diffusion-weighted imaging (DWI), T1-weighted imaging (T1WI), T2-weighted imaging (T2WI) were determined from preoperative MRI images. IHC markers including ER, PR, p53 and Ki67 were determined through IHC staining of preoperative curettage specimen. Patients were divided into high-risk and low-intermediate- risk group based on the final histological results. Differences between categorical and numerical variables were assessed using chi-square test and independent-sample t-test, respectively. Multivariate binary logistic regression analyses were used for construction of the prediction model A fusion prediction model was constructed by combining MRI features and IHC markers. The predictive performance of the model was then validated using the external cohort.

Results

Imaging and IHC markers were significantly associated with risk ranks. Model 1 based on MRI features showed an area under the curve (AUC) of 0.822 [95% confidence interval (CI), 0.741-0.903] whereas Model 2 based on IHC markers showed an AUC of 0.894 (95% CI, 0.829-0.960). Notably, model 3 integrating independent MRI and IHC risk factors demonstrated good calibration and high differentiation ability with an AUC of 0.958 (95% CI, 0.923-0.993), and showed good discrimination with an AUC of 0.84 (95% CI, 0.677-0.942) using the external validation set.

Conclusions

This study proposes a comprehensive predictive model comprising MRI and IHC features as a powerful tool for preoperative risk stratification to assist in clinical decision-making for EC patients.

Improving preoperative diagnosis in endometrial cancer using systematic morphological assessment and a small immunohistochemical panel

Preoperative histopathological classification determines the primary surgical approach in endometrial carcinoma (EC) patients but has only moderate agreement between preoperative and postoperative diagnosis. The aim of the PIpelle Prospective ENDOmetrial carcinoma (PIPENDO) study is to determine whether histopathological assessment and a small panel of diagnostic biomarkers decreases discrepancies between preoperative and postoperative diagnosis in EC. Preoperative endometrial tissue of 378 included patients with EC was stained with 15 different antibodies. Clinically relevant discrepancies in grade or histological subtype between original preoperative and reviewed postoperative diagnosis were observed in 75 (20%) patients. Highest clinically relevant discrepancy was found in grade 2 ECs (20%), compared to 5% and 14% in respectively grade 1 and 3 endometrioid endometrial carcinomas (EECs). A practical two-biomarker panel with PR and p53 improved diagnostic accuracy (AUC = 0.92; 95%CI = 0.88-0.95) compared to solely morphological evaluation (AUC = 0.86). In preoperative high-grade EC, the diagnostic accuracy of histological subtype was improved by a three-immunohistochemical biomarker panel (PR, IMP3, and L1CAM) (AUC = 0.93; 95%CI = 0.88-0.98) compared to solely morphological evaluation (AUC = 0.81). In conclusion to improve correct preoperative diagnosis in EC, we recommend use of a panel of at least two easily accessible immunohistochemical biomarkers (PR and p53), only in grade 2 ECs. Overall, this will reduce clinically relevant discrepancies in tumor grade and subtype with postoperative diagnosis with 6% (from 20% to 14%). Addition of PR, IMP3, and L1CAM for histological subtyping in high-grade EECs resulted in a further decrease in discrepancies with 8% (from 20% to 12%).

Evaluation of treatment effects in patients with endometrial cancer and POLE mutations: An individual patient data meta-analysis

BACKGROUND

Endometrial cancers (ECs) with somatic mutations in DNA polymerase epsilon (POLE) are characterized by unfavorable pathological features, which prompt adjuvant treatment. Paradoxically, women with POLE-mutated EC have outstanding clinical outcomes, and this raises concerns of overtreatment. The authors investigated whether favorable outcomes were independent of treatment.

METHODS

A PubMed search for POLE and endometrial was restricted to articles published between March 1, 2012, and March 1, 2018, that provided individual patient data (IPD), adjuvant treatment, and survival. Following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) reporting guidelines for IPD, the authors used univariate and multivariate one-stage meta-analyses with mixed effects Cox models (random effects for study cohorts) to infer the associations of treatment, traditional prognostic factors, and outcome, which was defined as the time from first diagnosis to any adverse event (progression/recurrence or death from EC).

RESULTS

Three hundred fifty-nine women with POLE-mutated EC were identified; 294 (82%) had pathogenic mutations. Worse outcomes were demonstrated in patients with nonpathogenic POLE mutations (hazard ratio, 3.42; 95% confidence interval, 1.47-7.58; log-rank P < .01). Except for stage (P < .01), traditional prognosticators were not associated with progression/recurrence or death from disease. Adverse events were rare (11 progressions/recurrences and 3 disease-specific deaths). Salvage rates in patients who experienced recurrence were high and sustained, with 8 of 11 alive without evidence of disease (range, 5.5-14.2 years). Adjuvant treatment was not associated with outcome.

CONCLUSIONS

Clinical outcomes for ECs with pathogenic POLE mutations are not associated with most traditional risk parameters, and patients do not appear to benefit from adjuvant therapy. The observed low rates of recurrence/progression and the high and sustained salvage rates raise the possibility of safely de-escalating treatment for these patients.

LAY SUMMARY

Ten percent of all endometrial cancers have mutations in the DNA repair gene DNA polymerase epsilon (POLE). Women who have endometrial cancers with true POLE mutations experience almost no recurrences or deaths from their cancer even when their tumors appear to have very unfavorable characteristics. Additional therapy (radiation and chemotherapy) does not appear to improve outcomes for women with POLE-mutated endometrial cancer, and this supports the move to less therapy and less associated toxicity. Diligent classification of endometrial cancers by molecular features provides valuable information to inform prognosis and to direct treatment/no treatment.

Factors influencing treatment decision and guideline conformity in high-grade endometrial cancer patients: a population-based study

PURPOSE

Treatment according to guidelines has been demonstrated to improve survival in a number of different cancer entities. Deviations from guidelines depend on several factors, including the patient's preferences, age and comorbidities. The aim of this study was to assess the adherence to guideline recommendations concerning surgical and adjuvant treatment in endometrial cancer. Furthermore, we sought to evaluate the reasons for non-adherence to guidelines by further examining the influence of comorbidities and age.

METHODS

The influence of age, comorbidities, tumor stage and histological subtype on guideline adherence was evaluated by multivariable logistic regression in a cohort of 353 high-grade endometrial cancer patients. High-grade endometrial cancer was defined as carcinosarcoma, Type II (serous, clear cell, mixed cell carcinoma) and Type I G3 histology.

RESULTS

Extensive surgical procedures, particularly systematic LNE, were less frequently applied in patients with comorbidities (p = 0.015) or higher age (p < 0.01). Guideline adherence was not affected by comorbidities (p = 0.563), but was significantly reduced with higher age (p < 0.01). In a multivariable model, higher age (p < 0.01), obesity (p = 0.011), higher FIGO Stage (p < 0.01) and histologic subtype (p < 0.01) significantly decreased OS. Surgery (p < 0.001), chemotherapy (p < 0.01) and systematic LNE (p = 0.011) were associated with higher OS.

CONCLUSION

Age seems to be the strongest independent factor leading to guideline deviation. Comorbidities were associated with less aggressive treatment, but not with deviations from guidelines.

Major clinical research advances in gynecologic cancer in 2020

In 2020 series, we summarized the major clinical research advances in gynecologic oncology with providing representative figures of the most influential study for 1 of each 3 gynecologic cancers: cervix, ovary, and uterine corpus. Review for cervical cancer covered targeted agents and immune checkpoint inhibitors, adjuvant radiation therapy or concurrent/sequential chemoradiation therapy after radical hysterectomy in early cervical cancer, radical surgery in early cervical cancer; and prevention and screening. Ovarian cancer research included studies of various combinations of poly (ADP-ribose) polymerase inhibitors with chemotherapy, immune checkpoint inhibitors, and/or vascular endothelial growth factor inhibitors according to the clinical setting. For uterine corpus cancer, molecular classification upon which the decision of adjuvant treatments might be based, World Health Organization recommendation of 2-tier grading system (low grade vs. high grade), sentinel lymph node assessment and ovarian preservation in clinically early-stage endometrial cancer were reviewed. Molecular targeted agents including immune checkpoint inhibitors which showed promising anti-tumor activities in advanced/recurrent endometrial cancer were also included in this review.

Prognostic impact of histological review of high-grade endometrial carcinomas in a large Danish cohort

The aim of this study was to investigate the outcome of histological subtype review of high-grade endometrial carcinoma (EC) and its prognostic impact in a large well-documented Danish nationwide cohort. From the Danish Gynecological Cancer Database (DGCD) 2005-2012 cohort, we included 425 patients with an original diagnosis of high-grade EC, independent of histologic subtype. Of these, at least one hematoxylin and eosin (H&E)-stained slide from 396 cases (93.2%) was available for review. The histologic subtype was reviewed by specialized gynecopathologists blinded to the original diagnosis and clinical outcome. Interobserver variability between original and revised histologic subtypes was analyzed using simple Kappa statistics. Hazard ratios (HR), recurrence-free survival (RFS), and overall survival were calculated for original and revised subtypes, respectively. Overall histologic subtype agreement was moderate (kappa = 0.42) with the highest agreement for endometrioid-type EC (EEC; 75.5%) and serous-type EC (SEC; 63.8%). For clear cell carcinoma and un-/dedifferentiated EC, agreement was significantly lower: 30.1% and 33.3% respectively. Of the 396 reviewed cases, only two (0.5%) were re-classified as low-grade EEC upon revision. Interestingly, GR3 EEC had better RFS than SEC with stronger significance after revision (HR 2.36 (95% CI 1.43-3.89), p = 0.001), compared to original diagnosis (HR 1.74 (95% CI 1.07-2.81), p = 0.024). In conclusion, this study confirmed that pathology review results in substantial shift in histological subtype in high-grade EC. After review, a stronger prognostic benefit for GR3 EEC as compared to other histological subtypes was observed. This work supports maintaining a low threshold for pathology revision of high-grade EC in clinical practice.

Predictive value of the new ESGO-ESTRO-ESP endometrial cancer risk classification on survival and recurrence in the Danish population

OBJECTIVE

To compare the performance of the new ESGO-ESTRO-ESP (European Society of Gynecological Oncology-European Society for Radiotherapy & Oncology-European Society for Pathology) 2020 risk classification system with the previous 2016 risk classification in predicting survival and patterns of recurrence in the Danish endometrial cancer population.

METHODS

This Danish national cohort study included 4516 patients with endometrial cancer treated between 2005 and 2012. Five-year Kaplan-Meier adjusted and unadjusted survival estimates and actuarial recurrence rates were calculated for the previous and the new classification systems.

RESULTS

In the 2020 risk classification system, 81.0% of patients were allocated to low, intermediate, or high-intermediate risk compared with 69.1% in the 2016 risk classification system, mainly due to reclassification of 44.5% of patients previously classified as high risk to either intermediate or especially high-intermediate risk. The survival of the 2020 high-risk group was significantly lower, and the recurrence rate, especially the non-local recurrence rate, was significantly higher than in the 2016 high risk group (2020/2016, overall survival 59%/66%; disease specific 69%/76%; recurrence 40.5%/32.3%, non-local 34.5%/25.8%). Survival and recurrence rates in the other risk groups and the decline in overall and disease-specific survival rates from the low risk to the higher risk groups were similar in patients classified according to the 2016 and 2020 systems.

CONCLUSION

The new ESGO-ESTRO-ESP 2020 risk classification system allocated fewer patients to the high risk group than the previous risk classification system. The main differences were lower overall and disease-specific survival and a higher recurrence rate in the 2020 high risk group. The introduction of the new 2020 risk classification will potentially result in fewer patients at high risk and allocation to the new high risk group will predict lower survival, potentially allowing more specific selection for postoperative adjuvant therapy.

Interlaboratory Concordance of ProMisE Molecular Classification of Endometrial Carcinoma Based on Endometrial Biopsy Specimens

Molecular classifiers improve the consistency of categorization of endometrial carcinoma and provide valuable prognostic information. We aimed to evaluate the interlaboratory agreement in ProMisE assignment across 3 dedicated Canadian gynecologic oncology centers. Fifty cases of endometrial carcinoma diagnosed on biopsy were collected from 3 centers and 3 unstained sections were provided to each participating site so that immunohistochemistry for MSH6, PMS2, and p53 could be performed and interpreted at each center, blinded to the original diagnoses and the results from other centers. A core was taken for DNA extraction and POLE mutation testing. Overall accuracy and κ statistic were assessed. MSH6, PMS2, and p53 could be assessed for all 50 cases, with agreement for 140/150 results. There was a high level of agreement in molecular classification (κ=0.82), overall. Cases with a discordant result for one of the features used in classification (n=10) were reviewed independently and the most common reason for disagreement was attributable to the weak p53 staining in 1 laboratory (n=4). Interpretive error in PMS2 (n=1) and MSH6 (n=2) assessment accounted for 3 of the remaining disagreements. Interpretive error in the assessment of p53 was identified in 2 cases, with very faint p53 nuclear reactivity being misinterpreted as wild-type staining. These results show strong interlaboratory agreement and the potential for greater agreement if technical and interpretive factors are addressed. Several solutions could improve concordance: central quality control to ensure technical consistency in immunohistochemical staining, education to decrease interpretation errors, and the use of secondary molecular testing.

Molecularly Classified Uterine FIGO Grade 3 Endometrioid Carcinomas Show Distinctive Clinical Outcomes But Overlapping Morphologic Features

FIGO grade 3 endometrioid endometrial carcinoma (EEC) is a heterogenous group of tumors with variable molecular and clinicopathologic characteristics but is treated clinically as a single entity. There is a need for additional objective markers to help guide management. The aim of this study was to evaluate a cohort of FIGO grade 3 EEC to validate the prognostic impact of molecular classification using POLE mutation (POLE-mut) analysis and immunohistochemistry for p53 and mismatch repair proteins. A secondary aim was to assess for any morphologic or immunophenotypic correlates among the molecular groups. Ninety-five cases of FIGO grade 3 EEC who underwent a hysterectomy at our institution were identified. Ten tumors (11%) harbored POLE-mut, 35 tumors (37%) showed mismatch repair deficiency, 18 tumors (19%) showed aberrant p53 staining (p53-ab), and 26 cases (27%) lacked all of these findings and were classified as no specific molecular profile. Six separate cases harbored >1 abnormality (multiple classifier), 5 of which had POLE-mut. The POLE-mut group and multiple classifier group showed excellent clinical outcomes, the p53-ab group showed the worst clinical outcomes and the 2 remaining groups showed intermediate prognosis. While the POLE-mut tumors showed a statistically significant enrichment for morphologic features including serous-like atypia and lymphocytic infiltrates, these findings were seen across all 4 molecular groups. There was no correlation between molecular grouping and tumor immunophenotypic findings, but overall 18% and 24% of tumors were completely negative for PAX-8 and estrogen receptor, respectively. Five CTNNB1 mutations were identified, 3 of which occurred in the context of a POLE-mut (including 1 multiple classifier case with MLH1/PMS2 loss). Thus our study corroborates the prognostic impact of molecular classification of high-grade endometrioid carcinoma of the uterus, achieved by readily available immunohistochemical stains in addition to POLE-mut analysis.

The TCGA Molecular Classification of Endometrial Cancer and Its Possible Impact on Adjuvant Treatment Decisions

Simple Summary

The Proactive Molecular Risk Classifier for Endometrial Cancer (ProMisE) is a recently developed tool to identify four distinct molecular subgroups of endometrial cancer. Patients identified as Polymerase Epsilon exonuclease domain mutated (POLE EDM) or p53-mutated have significantly altered prognosis compared to patients allocated to the mismatch repair deficient (MMRd) or p53 wt groups. The aim of this review is to give a broad overview over the initial development and refinement of the classifier as well as possible effects on the recommended adjuvant treatment. We have summarized the clinical data of 8 studies including 3650 endometrial cancer patients and analyzed the distribution of tumor stage and adjuvant treatment received in respect to the molecular subgroups. Based on the findings of the summarized studies treatment de-escalation might be feasible for POLE EDM patients while p53 abn patients should receive adjuvant (chemo-)radiotherapy.

Abstract

Adjuvant treatment decisions for endometrial cancer (EC) are based on stage, the histological grade of differentiation, histological subtype, and few histopathological markers. The Proactive Molecular Risk Classifier for Endometrial Cancer (ProMisE) identified four risk groups of EC patients using a combination of immunohistochemistry and mutation analysis: Polymerase Epsilon exonuclease domain mutated (POLE EDM), mismatch repair deficient (MMRd), p53 wild-type/copy-number-low (p53 wt), and p53-mutated/copy-number-high (p53 abn). Patients allocated to the POLE or abnormal p53 expression subtype are faced with a significantly altered outcome possibly requiring a modified adjuvant treatment decision. Within this review, we summarize the development of ProMisE, characterize the four molecular subtypes, and finally discuss its value in terms of a patient-tailored therapy in order to prevent significant under or overtreatment.

Trends in peritoneal cytology evaluation at hysterectomy for endometrial cancer in the United States

OBJECTIVE

The collection of a peritoneal cytologic sample at the time of surgery for endometrial cancer has traditionally been an important part of surgical staging. In 2009, the International Federation of Gynecology and Obstetrics revised the cancer staging schema for endometrial cancer and removed peritoneal cytology from the staging criteria. The current National Comprehensive Cancer Network guidelines and the International Federation of Gynecology and Obstetrics organization, however, recommend evaluation of peritoneal cytology at the time of hysterectomy. This study examined population-based trends, characteristics, and outcomes of peritoneal cytologic sampling for endometrial cancer surgery following the 2009 staging revision in the United States.

METHODS

This is a retrospective observational study querying the Surveillance, Epidemiology, and End Results Program to examine women with stage I-III endometrial cancer who underwent hysterectomy from 2010 to 2017. Trends, characteristics, and survival associated with peritoneal cytologic evaluation at the time of hysterectomy were assessed in multivariable analysis and with propensity score weighting.

RESULTS

Among 62,809 women who underwent hysterectomy, 43,873 (69.9%) had peritoneal cytologic evaluation at surgery and 18,936 (30.1%) did not. Utilization of peritoneal cytologic evaluation decreased from 75.5% to 64.9% during the study period (P < 0.001). In multivariable analysis, more recent year of surgery was independently associated with a decreased likelihood of performance of peritoneal cytology (adjusted-odds ratio of peritoneal cytology evaluation in 2017 versus 2010 0.56, 95% confidence interval [CI] 0.52-0.60). Peritoneal cytologic evaluation at the time of hysterectomy was associated with improved all-cause mortality (hazard ratio in the whole cohort 0.94, 95%CI 0.89-0.99; and hazard ratio in endometrioid histology 0.90, 95%CI 0.84-0.97).

CONCLUSION

Performance of peritoneal cytologic sampling has gradually decreased following the 2009 staging revision in the United States. Our study suggests that peritoneal cytology evaluation at hysterectomy may be associated with improved survival in certain tumor groups.

Endometrial Tumor Classification by Histomorphology and Biomarkers in the Nurses' Health Study

Objective

Endometrial cancers have historically been classified by histomorphologic appearance, which is subject to interobserver disagreement. As molecular and biomarker testing has become increasingly available, the prognostic significance and accuracy of histomorphologic diagnoses have been questioned. To address these issues for a large, prospective cohort study, we provide the results of a centralized pathology review and biomarker analysis of all incidental endometrial carcinomas occurring between 1976 and 2012 in the Nurses' Health Study.

Methods

Routine histology of all (n = 360) cases was reviewed for histomorphologic diagnosis. Cases were subsequently planted in a tissue microarray to explore expression of a variety of biomarkers (e.g., ER, PR, p53, PTEN, PAX2, AMACR, HNF1β, Napsin A, p16, PAX8, and GATA3).

Results

Histologic subtypes included endometrioid (87.2%), serous (5.6%), carcinosarcoma (3.9%), clear cell (1.7%), and mixed type (1.7%). Biomarker results within histologic subtypes were consistent with existing literature: abnormal p53 was frequent in serous cases (74%), and HNF1β (67%), Napsin A (67%), and AMACR (83%) expression was frequent in clear cell carcinomas. Our dataset also allowed for examination of biomarker expression across non-preselected histologies. The results demonstrated that (1) HNF1β was not specific for clear cell carcinoma, (2) TP53 mutations occurred across many histologies, and (3) GATA3 was expressed across multiple histotypes, with 75% of positive cases demonstrating high-grade features.

Conclusions

Our findings establish the subtypes of endometrial cancer occurring in the Nurses' Health Study, corroborate the sensitivity of certain well-established biomarkers, and call into question previously identified associations between certain biomarkers (e.g., HNF1B) and particular histotypes.

Equivalent Survival of p53 Mutated Endometrial Endometrioid Carcinoma Grade 3 and Endometrial Serous Carcinoma

TP53 status is the most important prognostic biomarker in endometrial carcinoma. We asked the question whether p53 mutated endometrial endometrioid carcinomas grade 3 (EEC3) or endometrial serous carcinomas (ESC), the latter ubiquitously harboring TP53 mutation, have different outcomes. TP53 mutation status was assessed by surrogate p53 immunohistochemistry on 326 EEC3 and ESC from 2 major cancer centers in Canada. Mutant-type p53 expression, including overexpression, complete absence, or cytoplasmic expression, was distinguished from the wild-type pattern. Statistical associations with clinico-pathological parameter, other key biomarkers, and survival analyses were performed. P53 mutant-type immunohistochemistry was observed in all 126 ESC and in 47/200 (23.5%) EEC3. ESC and p53 mutated EEC3 had an unfavorable outcome compared with p53 wild-type EEC3 (hazard ratio=2.37, 95% confidence interval=1.48-3.80, P=0.003, hazard ratio=2.19, 95% confidence interval=1.16-4.12, P=0.016, respectively) in multivariable analyses adjusted for age, stage, center, and presence of lymph-vascular invasion. There was no significant difference in survival between ESC and p53 mutated EEC3 in multivariable analysis. Furthermore, p53 mutated EEC3 and ESC almost completely overlapped in univariate survival analysis when mismatch repair (MMR)-deficient cases were excluded, which suggests that EEC3 harboring combined MMR deficiency and TP53 mutations behave more according to the MMR status. Significant differences between p53 mutated MMR-proficient EEC3 and ESC in PTEN and p16 expression status remained. p53 mutated, MMR-proficient EEC3 and ESC have overlapping survival significantly different from p53 wild-type EEC3, which justifies a similar treatment with current non-targeted standard therapy. Although this is so, separate classification should continue due to biological differences that will become important for future targeted therapy.

DNA mismatch repair deficiency and p53 abnormality are age-related events in mixed endometrial carcinoma with a clear cell component

Mixed endometrial carcinoma (MEC) is defined as a tumor composed of two or more spatially distinct subtypes, at least one of which is serous or clear cell carcinoma. In this study, the clinicopathological features of 15 MEC cases containing a clear cell component (MEC-C) were investigated. The ages of patients ranged from 32 to 83 years (median, 61 years). The combinations of carcinoma components observed were endometrioid and clear cell in ten patients; endometrioid, clear cell and serous in three; and clear cell and serous in two. Immunohistochemically, nine had DNA mismatch repair (MMR) protein deficiency (MMR-d), nine had loss of ARID1A and three cases had aberrant p53 expression. MMR-d and loss of ARID1A showed a strong correlation. Only one case showed both MMR-d and aberrant p53 expression. The patients with MMR-d were younger than those without MMR-d (median; 58 years vs. 71 years). Loss of ARID1A also showed significant predilection for younger women than ARID1A intact cases. In conclusion, MMR-d was observed in 60 % of MEC-C, showed predilection for young women, and was associated with ARID1A loss. In contrast, non- MMR-d MEC-C occurred in elder women and some tumors may associate with TP53 mutation. These findings suggest that MEC-C develop via two different molecular mechanisms and they are age-related events.

Endometrial cancer with a POLE mutation progresses frequently through the type I pathway despite its high-grade endometrioid morphology: a cohort study at a single institution in Japan

POLE-mutated endometrial cancer (EC) frequently shows high-grade endometrioid histology, which represents heterogeneity in the dualistic classification of EC. This study aimed to assess the clinicopathology and pathogenesis of POLE-mutated EC due to the scarcity of related information for Asian women. POLE variants were sequenced in tissues of Japanese women with EC. The tumor mutation burden (TMB) was assessed in tissues with a POLE variant of unknown significance. In the POLE-mutated EC tissues, the immunostaining expression of CD8, hormonal receptors, and p53 was evaluated, and the POLE variants in cancer and atypical endometrial hyperplasia (AEH) lesions were assessed by laser-capture microdissection. POLE variants were identified in five patients (3.9%) with high-grade endometrioid carcinoma among 127 patients with EC (S459F in two tissues and P441P in three tissues with a high TMB). The five cancer tissues coexisted with normal endometrium and/or AEH. Both AEH and cancer cells showed hormonal receptor positivity and harbored the same POLE mutation. Two patients showed a subclonal overexpression pattern of p53 in cancer and AEH lesions. In conclusion, POLE-mutated EC progresses through the type I pathway, even though it frequently shows high-grade endometrioid morphology. The common POLE mutation sites in EC might vary among races.

POLE, MMR, and MSI Testing in Endometrial Cancer: Proceedings of the ISGyP Companion Society Session at the USCAP 2020 Annual Meeting

Subclassification of endometrial carcinoma (EC) based on morphologic features alone has been shown to have suboptimal reproducibility, both in regard to biopsy versus hysterectomy findings, as well as interobserver agreement. This restricts the role of morphologic classification of EC as a tool for risk prediction and therefore treatment planning. A diagnostic algorithm based on The Cancer Genome Atlas (TCGA) classification of EC holds promise for improving accuracy in risk prediction. This classifies EC into 4 groups: those harbouring mutations in the exonuclease domain of DNA polymerase epsilon, POLE (POLEmut), those showing a mismatch repair defect, those showing mutations in TP53 (p53abn) and a heterogenous group showing none of these 3 abnormalities (currently termed no specific molecular profile). These groups can be accurately and reproducibly diagnosed on biopsy samples using a limited panel of tests, namely immunohistochemistry for mismatch repair proteins and p53, and testing for POLE exonuclease domain pathogenic variants. In this article we briefly review the biology, testing and interpretation of POLE and mismatch repair defects in EC.

Association of SNPs in CDKN2A (P14ARF) Tumour Suppressor Gene With Endometrial Cancer in Postmenopausal Women

BACKGROUND/AIM

This research was aimed to evaluate the association between three selected single nucleotide polymorphisms (SNPs) within the CDKN2A (P14ARF) tumour suppressor gene and the incidence of endometrial cancer (EC) in postmenopausal women.

PATIENTS AND METHODS

The study included 194 postmenopausal women; 144 with EC and 50 non-cancer controls. Genotypes in P14ARF rs3088440, rs3731217 and rs3731245 polymorphisms were assayed using PCR-RFLP and confirmed by sequencing.

RESULTS

Regarding the rs3088440 polymorphism, CT, and CT-TT genotypes, were more prevalent among EC patients than in controls (OR=5.55, p=0.023, OR=5.29, p=0.027; and OR=2.92, p=0.023, respectively). The T allele within rs3088440 was more prevalent in EC females than in controls (χ²=4.7, p=0.030). Considering rs3731217, TG and TG-GG genotypes were less prevalent among EC (OR=0.34, p=0.024 or p=0.023; and OR=0.38, p=0.035, respectively).

CONCLUSION

Polymorphisms in the CDKN2A gene are associated with EC in postmenopausal women.

Interobserver diagnostic reproducibility in advanced-stage endometrial carcinoma

Background

The accurate pathologic diagnosis and subtyping of high-grade endometrial carcinoma are often problematic, due to its atypical and overlapping histopathological features.

Methods

Three pathologists reviewed 21 surgically resected cases of advanced-stage endometrial carcinoma. The primary diagnosis was based only on hematoxylin and eosin stained slides. When a discrepancy arose, a secondary diagnosis was made by additional review of immunohistochemical (IHC) stains. Finally, three pathologists discussed all cases and rendered a consensus diagnosis.

Results

The primary diagnoses were identical in 13/21 cases (62%). The secondary diagnosis based on the addition of IHC results was concordant in four of eight discrepant cases. Among four cases with discrepancies occurring in this step, two cases subsequently reached a consensus diagnosis after a thorough discussion between three reviewers. Next-generation sequencing (NGS) study was performed in two cases in which it was difficult to distinguish between serous carcinoma and endometrioid carcinoma. Based on the sequencing results, a final diagnosis of serous carcinoma was rendered. The overall kappa for concordance between the original and consensus diagnosis was 0.566 (moderate agreement).

Conclusions

We investigated stepwise changes in interobserver diagnostic reproducibility in advanced-stage endometrial carcinoma. We demonstrated the utility of IHC and NGS study results in the histopathological diagnosis of advanced-stage endometrial carcinoma.

Preoperative assessment of endometrial cancer

Endometrial cancer (EC), the most common among gynaecological malignancies occurs predominantly after the menopause. The diagnosis is most commonly (in about 75-80%) set up at early stage when surgical therapy and if necessary postoperative radiotherapy results in an excellent prognosis, with a 90-95% 5-year overall survival (OS) and a locoregional recurrence rates of 4-8%. Accurate preoperative assessment of the lymph nodes would ideally identify those patients with advanced stage disease, who might benefit from more extensive surgical procedures and adjuvant therapies. magnetic resonance imaging (MRI), hysteroscopic excisional biopsy (HEB) and high resolution 2D or 3D ultrasound performed by expert operator are considered to add valuable information for preoperative staging of EC. The use of biomarkers could be beneficial in decreasing inter-observer variability between the histology of the diagnostic specimen and the final operative sample, as well as to avoid overtreatment in a part of the high-grade tumors with excellent prognosis. The goal of surgical management of EC is to remove the primary tumor and to identify definite prognostic factors to determine whether adjuvant therapy is required. Extended surgery, including para-aortic lymphadenectomy has a significant morbidity, and with the future selection of cases it can be safely avoided, we can decrease complications without compromising oncological safety. In the future, the importance of hysteroscopy guided sampling may increase to gain a representative sample for biomarker detection.

Pten and Dicer1 loss in the mouse uterus causes poorly differentiated endometrial adenocarcinoma

Endometrial cancer remains the most common gynecological malignancy in the United States. While the loss of the tumor suppressor, PTEN (phosphatase and tensin homolog), is well studied in endometrial cancer, recent studies suggest that DICER1, the endoribonuclease responsible for miRNA genesis, also plays a significant role in endometrial adenocarcinoma. Conditional uterine deletion of Dicer1 and Pten in mice resulted in poorly differentiated endometrial adenocarcinomas, which expressed Napsin A and HNF1B (hepatocyte nuclear factor 1 homeobox B), markers of clear-cell adenocarcinoma. Adenocarcinomas were hormone-independent. Treatment with progesterone did not mitigate poorly differentiated adenocarcinoma, nor did it affect adnexal metastasis. Transcriptomic analyses of DICER1 deleted uteri or Ishikawa cells revealed unique transcriptomic profiles and global miRNA downregulation. Computational integration of miRNA with mRNA targets revealed deregulated let-7 and miR-16 target genes, similar to published human DICER1-mutant endometrial cancers from TCGA (The Cancer Genome Atlas). Similar to human endometrial cancers, tumors exhibited dysregulation of ephrin-receptor signaling and transforming growth factor-beta signaling pathways. LIM kinase 2 (LIMK2), an essential molecule in p21 signal transduction, was significantly upregulated and represents a novel mechanism for hormone-independent pathogenesis of endometrial adenocarcinoma. This preclinical mouse model represents the first genetically engineered mouse model of poorly differentiated endometrial adenocarcinoma.

A Modern Approach to Endometrial Carcinoma: Will Molecular Classification Improve Precision Medicine in the Future?

Endometrial cancer has been histologically classified as either an estrogen-dependent cancer with a favorable outcome or an estrogen-independent cancer with a worse prognosis. These parameters, along with the clinical attributions, have been the basis for risk stratification. Recent molecular and histopathological findings have suggested a more complex approach to risk stratification. Findings from the Cancer Genome Atlas Research Network established four distinctive genomic groups: ultramutated, hypermutated, copy-number low and copy-number high prognostic subtypes. Subsequently, more molecular and histopathologic classifiers were evaluated for their prognostic and predictive value. The impact of molecular classification is evident and will be recognized by the upcoming WHO classification. Further research is needed to give rise to a new era of molecular-based endometrial carcinoma patient care.

Endometrial Cancer as a Metabolic Disease with Dysregulated PI3K Signaling: Shedding Light on Novel Therapeutic Strategies

Endometrial cancer (EC) is one of the most common malignancies of the female reproductive organs. The most characteristic feature of EC is the frequent association with metabolic disorders. However, the components of these disorders that are involved in carcinogenesis remain unclear. Accumulating epidemiological studies have clearly revealed that hyperinsulinemia, which accompanies these disorders, plays central roles in the development of EC via the insulin-phosphoinositide 3 kinase (PI3K) signaling pathway as a metabolic driver. Recent comprehensive genomic analyses showed that over 90% of ECs have genomic alterations in this pathway, resulting in enhanced insulin signaling and production of optimal tumor microenvironments (TMEs). Targeting PI3K signaling is therefore an attractive treatment strategy. Several clinical trials for recurrent or advanced ECs have been attempted using PI3K-serine/threonine kinase (AKT) inhibitors. However, these agents exhibited far lower efficacy than expected, possibly due to activation of alternative pathways that compensate for the PIK3-AKT pathway and allow tumor growth, or due to adaptive mechanisms including the insulin feedback pathway that limits the efficacy of agents. Overcoming these responses with careful management of insulin levels is key to successful treatment. Further interest in specific TMEs via the insulin PI3K-pathway in obese women will provide insight into not only novel therapeutic strategies but also preventive strategies against EC.

Clinical Predictive Factors of Response to Treatment in Patients Undergoing Conservative Management of Atypical Endometrial Hyperplasia and Early Endometrial Cancer

Purpose: Predictive markers of response to conservative treatment of atypical endometrial hyperplasia (AEH) or early endometrial cancer (EEC) are still lacking. We aimed to assess clinical predictive factors of response to conservative treatment of AEH and EEC. Methods: All patients with AEH or EEC conservatively treated from January 2007 to June 2018 were retrospectively assessed. The associations between 23 clinical factors and outcomes of response to treatment were assessed with standard univariate analyses and multivariate logistic regression (significant p-value <0.05). The primary outcome was the association of each clinical factor with treatment failure (i.e., no regression or relapse of the disease). Secondary outcomes were the associations of each clinical factor with: (1) no regression, (2) relapse, or (3) pregnancy after treatment. Results: Forty-three women, 37 (86%) with AEH and 6 (14%) with EEC were included. At univariate analyses, treatment failure was associated with longer menstrual cycle (p = 0.002), infrequent menstrual bleeding (p = 0.04), and a diagnosis of EEC instead of AEH (p = 0.008). Among the secondary outcomes, no regression was associated with infrequent menstrual bleeding (p = 0.04), and a diagnosis of EEC instead of AEH (p < 0.001), while relapse was associated with longer menstrual cycles (p = 0.007). At multivariate analyses, odds ratio for treatment failure was 4.54 (95% confidence interval [CI], 0.24-84.4) for a diagnosis of EEC instead of AEH (p = 0.3), and 2.10 (95% CI, 1.03-4.29) for longer menstrual cycles (p = 0.042), while infrequent menstrual bleeding perfectly predicted treatment failure. Conclusions: Longer menstrual cycles and infrequent menstrual bleeding appear as independent predictive factors for conservative treatment failure in AEH and EEC. Further and larger studies are necessary to confirm these findings.

Excess Body Weight and Incidence of Type 1 and Type 2 Endometrial Cancer: The Norwegian Women and Cancer Study

PURPOSE

Excess body weight has been associated with increased risk of 13 cancer types and is a particularly strong risk factor for endometrial cancer (EC). Only a few previous studies have assessed the relationship between excess body weight and EC subtypes. In this study, we aimed to investigate the associations between excess weight and incidence of type 1 and type 2 EC.

PATIENTS AND METHODS

We used data from 151,537 participants in the Norwegian Women and Cancer (NOWAC) cohort of which 935 were diagnosed with type 1 and 263 with type 2 EC during follow-up. Height and body weight were self-reported. Multivariable Cox proportional hazard regression was used to assess the associations between body mass index (BMI) and type 1 and type 2 EC.

RESULTS

For every 2 kg/m2 increase in BMI, the risk of type 1 EC increased by 21% (HR=1.21, 95% CI: 1.18, 1.24) and the risk of type 2 EC by 10% (HR=1.10, 95% CI: 1.03, 1.16) (pheterogeneity = 0.009). During the period 1991 to 2016, 24.0% (95% CI: 20.0% to 27.8%) of type 1 EC cases was attributable to excess body weight. Avoiding obesity could have prevented 6.6% (95% CI: 3.4% to 9.7%) of type 2 EC cases.

CONCLUSION

Excess body weight was associated with both type 1 and type 2 EC in a dose-dependent manner and the association was significantly stronger in type 1 EC. These findings could support the hypothesis that estrogen plays a more important role in the development of type 1 ECs than in type 2 EC.

Endometrial Carcinomas with a "Serous" Component in Young Women Are Enriched for DNA Mismatch Repair Deficiency, Lynch Syndrome, and POLE Exonuclease Domain Mutations

Endometrial carcinoma (EC), as described by Bokhman, has historically been classified as Type I (low-grade, hormone-dependant, young patients, good prognosis) or Type II (high-grade, hormone-independent, older patients, poor prognosis). This classification is no longer pragmatic, however, as EC is a much more heterogeneous disease. Four molecular subtypes of EC were identified by The Cancer Genome Atlas (TCGA), and subsequent studies have demonstrated its utility in predicting prognosis. While endometrial serous carcinoma (ESC), the prototypical Type II EC, largely occurs in older women, younger women with ESC were not accounted for in the Bokhman model and were underrepresented in the TCGA study. We hypothesized that a subset of ESCs in young patients do not represent bona fide serous carcinomas but rather high-grade endometrioid carcinomas mimicking a serous phenotype. We identified ESCs and mixed endometrioid/serous carcinomas in women <60 years (n=37), and analyzed their clinical, morphologic, immunohistochemical, and molecular characteristics. Sixteen percent showed mismatch repair deficiency (MMR-D) and 11% were diagnosed with Lynch syndrome. Additionally, 16% of cases tested harbored a hotspot POLE exonuclease domain mutation (POLE-EDM). Morphologically, 47% of tumors showed confirmatory endometrioid features, including atypical hyperplasia, a low-grade endometrioid carcinoma component, or squamous differentiation. Clinically, the overall survival in patients with MMR-D and POLE-EDM was significantly better than that of patients without these features (P=0.0329). In conclusion, ESCs in young patients comprise a heterogeneous group of tumors, demonstrating diverse clinical, immunohistochemical, morphologic, and molecular features which have implications for prognosis and adjuvant therapy.

Immune disorder in endometrial cancer: Immunosuppressive microenvironment, mechanisms of immune evasion and immunotherapy

Immunotherapy is an emerging clinical approach that has gained traction over the past decade as a novel treatment option for lung cancer and melanoma. Notably, researchers have made marked improvements in the treatment of endometrial cancer (EC), and potential immune responses have been identified in patients with EC, thereby offering the possibility of exploring immunotherapy for EC. Nevertheless, various needs remain unmet, and immunotherapy applications in EC have yielded limited success, as only a minority of patients exhibited a clinical response. Therefore, further understanding of immune dysfunction associated with EC is still required. The present review describes recent findings regarding the immunosuppressive microenvironment of EC, with emphasis on immune evasion mechanisms and immunotherapy in EC.

Diagnostic accuracy of p53 immunohistochemistry as surrogate of TP53 sequencing in endometrial cancer

Aberrant p53 immunohistochemical expression is used to identify the copy-number-high/TP53-mutant subgroup of endometrial cancer (EC). We aimed to determine the diagnostic accuracy of p53 immunohistochemistry as surrogate for TP53 sequencing through a systematic review and meta-analysis. Electronic databases were searched from their inception to June 2019. All studies assessing p53 expression and TP53 mutations in EC were included. Diagnostic accuracy was assessed based on area under the curve (AUC). Immunohistochemical criteria used to define aberrant p53 expression were "overexpression" and "overexpression or complete absence". Subgroup analysis was based on the sequencing technique adopted (Polymerase Chain Reaction + sequencing, or next generation sequencing, NGS). Thirteen observational studies with 727 endometrial cancers were included. Both "overexpression" and "overexpression or complete absence" showed high diagnostic accuracy (AUC = 0.9088 and 0.9030, respectively). The subgroup with "overexpression" and NGS showed the best results, with very high diagnostic accuracy (AUC = 0.9927). In conclusion, immunohistochemistry for p53 is a highly accurate surrogate of TP53 sequencing. Overexpression of p53 in ≥70-80% showed the best accuracy in predicting TP53 mutations. Further studies in this field should adopt optimized immunohistochemical procedures and take into account less common p53 patterns (e.g. cytoplasmic expression).

Improving response to progestin treatment of low-grade endometrial cancer

OBJECTIVES

This review examines how response rates to progestin treatment of low-grade endometrial cancer can be improved. In addition to providing a brief overview of the pathogenesis of low-grade endometrial cancer, we discuss limitations in the current classification of endometrial cancer and how stratification may be refined using molecular markers to reproducibly identify 'low-risk' cancers which may represent the best candidates for progestin therapy. We also discuss constraints in current approaches to progestin treatment of low-grade endometrial cancer and perform a systematic review of predictive biomarkers.

METHODS

PubMed, ClinicalTrials.gov, and Cochrane Library were searched for studies reporting pre-treatment biomarkers associated with outcome in women with low-grade endometrial cancer or endometrial hyperplasia with an intact uterus who received progestin treatment. Studies of fewer than 50 women were excluded. The study protocol was registered in PROSPERO (ID 152374). A descriptive synthesis of pre-treatment predictive biomarkers reported in the included studies was conducted.

RESULTS

Of 1908 records reviewed, 19 studies were included. Clinical features such as age or body mass index cannot predict progestin response. Lesions defined as 'low-risk' by FIGO criteria (stage 1A, grade 1) can respond well; however, the reproducibility and prognostic ability of the current histopathological classification system is suboptimal. Molecular markers can be reproducibly assessed, have been validated as prognostic biomarkers, and may inform patient selection for progestin treatment. DNA polymerase epsilon (POLE)-ultramutated tumors and a subset of p53 wild-type or DNA mismatch repair (MMR)-deficient tumors with 'low-risk' features (eg, progesterone and estrogen receptor-positive) may have improved response rates, though this needs to be validated.

DISCUSSION

Molecular markers can identify cases which may be candidates for progestin treatment. More work is needed to validate these biomarkers and potentially identify new ones. Predictive biomarkers are anticipated to inform future research into progestin treatment of low-grade endometrial cancer and ultimately improve patient outcomes.

Molecular subtypes of clear cell carcinoma of the endometrium: Opportunities for prognostic and predictive stratification

OBJECTIVE

Our aim was to characterize the pathological, molecular and clinical outcomes of clear cell carcinoma of the endometrium (CCC).

METHODS

CCC underwent ProMisE (Proactive Molecular Risk Classifier for Endometrial Cancer) classification identifying four molecular subtypes: i) 'POLEmut' for ECs with pathogenic POLE mutations, ii) 'MMRd', if there is loss of mismatch repair proteins by immunohistochemistry (IHC), iii) 'p53wt' or iv) 'p53abn' based on p53 IHC staining. Clinicopathologic parameters, immune markers (CD3, CD8, CD79a, CD138, PD-1), ER, L1CAM, and outcomes were assessed.

RESULTS

52 CCCs were classified, including 1 (2%) POLEmut, 5 (10%) MMRd, 28 (54%) p53wt and 18 (35%) p53abn. Women with p53abn and p53wt CCCs were older than women with MMRd and POLEmut subtypes. p53wt CCC were distinct from typical p53wt endometrioid carcinomas; more likely to arise in older, thinner women, with advanced stage disease, LVSI and lymph node involvement, and a higher proportion ER negative, L1CAM overexpressing tumors with markedly worse outcomes. High levels of immune infiltrates (TIL^high) were observed in 75% of the CCC cohort. L1CAM overexpression was highest within p53abn and p53wt subtypes of CCC.

CONCLUSION

CCC is a heterogeneous disease encompassing all four molecular subtypes and a wide range of clinical outcomes. Outcomes of patients with POLEmut, MMRd and p53abn CCC are not distinguishable from those of other patients with these respective subtypes of EC; p53wt CCC, however, differ from endometrioid p53wt EC in clinical, pathological, molecular features and outcomes. Thus, p53wt CCC of endometrium appear to be a distinct clinicopathological entity within the larger group of p53wt ECs.

Clinicopathological characteristics and prognostic value of POLE mutations in endometrial cancer: A systematic review and meta-analysis

BACKGROUND

The aim of this meta-analysis was to assess the clinicopathological features and to confirm prognostic value of POLE exonuclease domain mutations (EDM) in endometrial carcinoma patients.

METHODS

The PubMed, Web of Science, the data of China National Knowledge Infrastructure, and Wan fang Medical Network were systematically searched for relevant articles without a cut-off date. The keywords for the search were "endometrial cancer," "endometrial carcinoma," "EC," "POLE mutations," "POLE exonuclease domain mutations," "POLE-mutant," "clinical characteristics" "prognostic." Pooled hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated by using Review manager 5.3 and Stata 14.0 statistical software.

RESULTS

Six cohort studies assessing 179 EC patients with POLE EDMs were included. The results indicated a favorable progression-free survival in POLE-mutant patients (HR = 0.32; 95% CI: = [0.09-1.18]). Furthermore, the overall survival was great in patients with POLE-mutant (HR = 0.68; 95% CI = [0.41-1.13]). It was shown that a significantly higher incidence of POLE mutations with Federation of International of Gynecologists and Obstetricians (FIGO) I group compared to FIGO II-IV group (pooled ORs: 0.34, 95% CI: [0.12-0.94], P = .04), POLE-mutant EC was not significantly associated with histology (OR = 0.56,95% CI: 0.29-1.23), tumor grade (OR = 1.22,95% CI:0.85-1.74), lymph-vascular space invasion (OR = 0.40,95% 0.06-2.42), depth of myometrial invasion (OR = 0.70,95% CI: 0.41-1.18), lymph node status (OR = 0.41, 95% 0.04-4.50), and European Society for Medical Oncology risk groups (OR = 0.68,95% CI: 0.37-1.26).

CONCLUSION

This meta-analysis has confirmed POLE EDMs may serve as a predictive biomarker of favorable prognosis. Further studies are needed to explore the appropriate clinical utility of POLE EDMs in EC.

Analysis of 108 patients with endometrial carcinoma using the PROMISE classification and additional genetic analyses for MMR-D

OBJECTIVES

To apply the Proactive Molecular Risk Classifier for Endometrial Cancer (ProMisE) to a consecutive series of endometrial cancer (EC) patients diagnosed at a tertiary referral center and assign EC specimens to one of four molecular subgroups using immunohistochemistry (IHC) for p53/mismatch repair protein expression and sequencing for Polymerase Epsilon Exonuclease Domain Mutations (POLE-EDM). Mismatch Repair Deficient (MMR-D) cases were more thoroughly investigated to identify underlying somatic or germline genetic defects.

METHODS

Hundred-and eight consecutive endometrial cancer patients, diagnosed between March 2017 and April 2019, were subjected to immunohistochemical and molecular analysis, according to ProMisE. IHC for p53 and the mismatch repair proteins (MLH1, PMS2, MSH6 and PMS2) was performed. All patients were also tested for POLE-EDM by Sanger sequencing. In addition, tumor and corresponding normal tissue of cases with abnormal MMR IHC were tested by PCR for microsatellite instability (MSI) (MSI analysis system, Promega). Hypermethylation of MLH1 promotor was tested with (methylation specific) multiplex ligation dependent probe amplification. MMR-D cases were subjected to germline mutation analysis of the mismatch repair genes, using next generation sequencing on MiSeq (Illumina) with the BRCA Hereditary Cancer MASTR Plus, (Multiplicom/Agilent), RNA mutation analysis and MLPA.

RESULTS

FIGO classification was stage IA (n = 54), IB (n = 22) II(n = 8), III(n = 18) and IV(n = 6). Of the 33 patients with MMR-D on IHC (31%), 26 showed MLH1 promotor hypermethylation as the probable cause of MMR-D. The remaining 7 patients without MLH1 promotor hypermethylation were referred for germline analysis of Lynch syndrome. Six patients carried a pathogenic germline mutation in one of the mismatch repair genes: MSH6(n = 3), PMS2(n = 1), MLH1(n = 1) and MSH2 (n = 1). Pathogenic POLE-EDM were identified in 7 (6%) patients. Multiple molecular features (POLE-EDM + MMR-D or POLE-EDM + p53 abnormal) were observed in 4 patients (4%). A high concordance between MMR-D and microsatellite instability was observed in our cohort. In cases of a genetic defect in the MMR genes, we do note a large proportion of cases exhibiting microsatellite instability. On the contrary a hypermutation state, as seen in POLE EDM, does not result in accompanied phenotypic changes in MSI status.

CONCLUSION

The ProMisE classification proved to be an efficient and easily implementable system. Future research should elucidate the precise biological and prognostic meaning of the cases with multiple molecular markers.

High-resolution copy number analysis of clear cell endometrial carcinoma

Uterine cancer is the 6th leading cause of cancer death amongst American women. Most uterine cancers are endometrial carcinomas (ECs), which are classified into histological subtypes including endometrioid, serous, and clear cell ECs. Somatic copy number alterations (SCNAs) are frequent in serous EC, infrequent in endometrioid ECs, and poorly defined in clear cell ECs. The purpose of this study was to evaluate the occurrence of SCNAs in clinically diagnosed clear cell ECs. Paired tumor-normal DNAs for 51 ECs were hybridized to Illumina Infinium HumanHap650Y or Human660W-Quad Beadchips. Copy number calls were made using the Hidden Markov Model based SNP-FASST2 segmentation algorithm within Nexus Copy Number software (v.6.1). High-level SCNAs were defined as gain of ≥5 copies or homozygous deletion, both <10Mb. GISTIC 1.0, in Nexus, was used to identify statistically significant SCNAs, corrected for multiple testing. One or more high-level SCNAs were detected in 50% of 6 clear cell ECs, 78.6% of 28 serous ECs, and 17.6% of 17 endometrioid ECs. A positive association was found between high-level SCNAs and TP53 mutation across ECs (two-tailed p value<0.0001). Classifying tumors according to POLE, MSI, and TP53 status yielded four molecular subgroups; copy number altered tumors were more frequent in the TP53-mutated subgroup (95.8%) than in the unspecified subgroup (22.2%), and absent from the POLE and MSI subgroups. In conclusion, our study provides evidence of inter-tumor heterogeneity in the extent to which SCNAs occur in clinically diagnosed clear cell EC, and across molecular subgroups of EC. The co-occurrence of high-level SCNAs and TP53 mutations in some clear cell ECs is consistent with the view that a subset of clinically diagnosed clear cell ECs have molecular similarities to serous ECs.

Classification of Endometrial Carcinoma: New Perspectives Beyond Morphology

Endometrial carcinoma has been traditionally divided into type 1 or endometrioid type that is usually moderate to well differentiated and type 2 that is usually poorly differentiated with high histologic grade and aggressive clinical behavior. However, interobserver diagnostic agreement is suboptimal, particularly among the high-grade histotypes. Furthermore, recent data indicate that this histotype assignment does not independently correlate with survival. In recent years, there has been remarkable progress in our understanding of the molecular basis of endometrial carcinoma and extensive molecular studies have been performed under The Cancer Genome Atlas Program (TCGA) leading to molecular classification of endometrial carcinoma that has been shown to be significantly prognostic. This classification system divides the tumors into 4 subgroups namely, polymerase ε exonuclease (POLE) ultramutated, hypermutated microsatellite instability, copy number low, and copy number high (serous-like). Carcinomas with POLE domain hotspot mutations are highly prognostically favorable; those with copy number alterations and TP53 mutations are highly aggressive; and microsatellite unstable and "copy number low" endometrioid are associated with intermediate prognoses. The TCGA applied methods that are too costly and cumbersome for widespread implementation into routine clinical practice. Several other groups have attempted to identify these categories by using immunohistochemical biomarkers rather than molecular studies. Immunohistochemical biomarkers have been used successfully to identify all the subgroups except for POLE ultramutated, which requires sequencing for proper categorization. It is hoped that future studies will identify a suitable biomarker for POLE mutation so that this classification can be routinely used in all medical centers.

Final validation of the ProMisE molecular classifier for endometrial carcinoma in a large population-based case series

Background

We have previously developed and confirmed a pragmatic molecular classifier for endometrial cancers; ProMisE (Proactive Molecular Risk Classifier for Endometrial Cancer). Inspired by the Cancer Genome Atlas, ProMisE identifies four prognostically distinct molecular subtypes and can be applied to diagnostic specimens (biopsy/curettings) enabling earlier informed decision-making. We have strictly adhered to the Institute of Medicine (IOM) guidelines for the development of genomic biomarkers, and herein present the final validation step of a locked-down classifier before clinical application.

Patients and methods

We assessed a retrospective cohort of women from the Tübingen University Women's Hospital treated for endometrial carcinoma between 2003 and 2013. Primary outcomes of overall, disease-specific, and progression-free survival were evaluated for clinical, pathological, and molecular features.

Results

Complete clinical and molecular data were evaluable from 452 women. Patient age ranged from 29 to 93 (median 65) years, and 87.8% cases were endometrioid histotype. Grade distribution included 282 (62.4%) G1, 75 (16.6%) G2, and 95 (21.0%) G3 tumors. 276 (61.1%) patients had stage IA disease, with the remaining stage IB [89 (19.7%)], stage II [26 (5.8%)], and stage III/IV [61 (13.5%)]. ProMisE molecular classification yielded 127 (28.1%) MMR-D, 42 (9.3%) POLE, 55 (12.2%) p53abn, and 228 (50.4%) p53wt. ProMisE was a prognostic marker for progression-free (P = 0.001) and disease-specific (P = 0.03) survival even after adjusting for known risk factors. Concordance between diagnostic and surgical specimens was highly favorable; accuracy 0.91, κ 0.88.

Discussion

We have developed, confirmed, and now validated a pragmatic molecular classification tool (ProMisE) that provides consistent categorization of tumors and identifies four distinct prognostic molecular subtypes. ProMisE can be applied to diagnostic samples and thus could be used to inform surgical procedure(s) and/or need for adjuvant therapy. Based on the IOM guidelines this classifier is now ready for clinical evaluation through prospective clinical trials.

Unique Molecular Features in High-Risk Histology Endometrial Cancers

Endometrial cancer is the most common gynecologic malignancy in the United States and the sixth most common cancer in women worldwide. Fortunately, most women who develop endometrial cancer have low-grade early-stage endometrioid carcinomas, and simple hysterectomy is curative. Unfortunately, 15% of women with endometrial cancer will develop high-risk histologic tumors including uterine carcinosarcoma or high-grade endometrioid, clear cell, or serous carcinomas. These high-risk histologic tumors account for more than 50% of deaths from this disease. In this review, we will highlight the biologic differences between low- and high-risk carcinomas with a focus on the cell of origin, early precursor lesions including atrophic and proliferative endometrium, and the potential role of stem cells. We will discuss treatment, including standard of care therapy, hormonal therapy, and precision medicine-based or targeted molecular therapies. We will also discuss the impact and need for model systems. The molecular underpinnings behind this high death to incidence ratio are important to understand and improve outcomes.

Current recommendations and recent progress in endometrial cancer

Endometrial cancer is the most common gynecologic cancer in the United States, and its incidence is rising. Although there have been significant recent advances in our understanding of endometrial cancer biology, many aspects of treatment remain mired in controversy, including the role of surgical lymph node assessment and the selection of patients for adjuvant radiation or chemotherapy. For the subset of women with microsatellite-instable, metastatic disease, anti- programmed cell death protein 1 immunotherapy (pembrolizumab) is now approved by the US Food and Drug Administration, and numerous trials are attempting to build on this early success.

Impact of TP53 immunohistochemistry on the histological grading system for endometrial endometrioid carcinoma

Endometrial endometrioid carcinoma is usually divided into three histological subgroups: grade 1 (G1), grade 2 (G2), and grade 3 (G3). Most cases of endometrial endometrioid carcinoma G1/2 have a favorable prognosis, although some can have unfavorable outcomes, especially when they involve elderly patients, with similarities to endometrioid carcinoma G3 and serous carcinoma. This retrospective study evaluated whether TP53 abnormalities in endometrial endometrioid carcinoma could be used to supplement the current grading system and improve its ability to predict clinical outcomes. Immunohistochemical expression of TP53 was analyzed using tissue microarrays from the surgically resected specimens of 475 patients with endometrial endometrioid carcinoma. Weak or moderate expression was defined as TP53-normal expression, while absent or strongly positive expression was defined as TP53-aberrant expression. The endometrial endometrioid carcinomas had originally been diagnosed as G1 (69%), G2 (18%), and G3 (13%). Univariate analyses revealed that TP53-aberrant expression was associated with poor survival in G1 and G2 cases, but not G3 cases. In addition, age (<60 years vs. ≥60 years) was correlated with TP53-aberrant expression in G1 cases (3% vs. 16%, p = 0.001), but not in G2 or G3 cases. Based on immunohistochemical TP53 expression, the endometrial endometrioid carcinomas were reclassified using a prognostic grading system as high-grade (G1 or G2 with TP53- aberrant expression, and G3 with TP53-normal or -aberrant expression) or low-grade (G1 or G2 with TP53-normal expression). The multivariate analyses revealed that the prognostic grading system (using histological grade and TP53 expression) could independently predict poor progression-free survival (hazard ratio: 2.91, p < 0.001) and overall survival (hazard ratio: 3.62, p < 0.001). Therefore, combining immunohistochemical TP53 expression with the traditional histological grading system for endometrial endometrioid carcinoma may help improve its ability to accurately predict the patient's prognosis.

Addition of IMP3 to L1CAM for discrimination between low- and high-grade endometrial carcinomas: a European Network for Individualised Treatment of Endometrial Cancer collaboration study

Discrimination between low- and high-grade endometrial carcinomas (ECs) is clinically relevant but can be challenging for pathologists, with moderate interobserver agreement. Insulin-like growth factor-II mRNA-binding protein 3 (IMP3) is an oncofoetal protein that is associated with nonendometrioid endometrial carcinomas but has been limited studied in endometrioid carcinomas. The aim of this study is to investigate the diagnostic and prognostic value of IMP3 in the discrimination between low- and high-grade ECs and its added value to L1CAM. IMP3 and L1CAM expression was assessed in tumors from 378 patients treated for EC at 1 of 9 participating European Network for Individualised Treatment of Endometrial Cancer centers. IMP3 was expressed in 24.6% of the tumors. In general, IMP3 was more homogeneously expressed than L1CAM. IMP3 expression was significantly associated with advanced stage, nonendometrioid histology, grade 3 tumors, deep myometrial invasion, lymphovascular space invasion, distant recurrences, overall mortality, and disease-related mortality. Simultaneous absence of IMP3 and L1CAM expression showed the highest accuracy for identifying low-grade carcinomas (area under the curve 0.766), whereas simultaneous expression of IMP3 and L1CAM was strongly associated with high-grade carcinomas (odds ratio 19.7; 95% confidence interval 9.2-42.2). Even within endometrioid carcinomas, this combination remained superior to IMP3 and L1CAM alone (odds ratio 8.6; 95% confidence interval 3.4-21.9). In conclusion, IMP3 has good diagnostic value and together with L1CAM represents the optimal combination of diagnostic markers for discrimination between low- and high-grade ECs compared to IMP3 and L1CAM alone. Because of the homogenous expression of IMP3, this marker might be valuable in preoperative biopsies when compared to the more patchy L1CAM expression.

Identification of Potential Crucial Genes Associated With the Pathogenesis and Prognosis of Endometrial Cancer

Background and Objective

Endometrial cancer (EC) is a common gynecological malignancy worldwide. Despite advances in the development of strategies for treating EC, prognosis of the disease remains unsatisfactory, especially for advanced EC. The aim of this study was to identify novel genes that can be used as potential biomarkers for identifying the prognosis of EC and to construct a novel risk stratification using these genes.

Methods and Results

An mRNA sequencing dataset, corresponding survival data and expression profiling of an array of EC patients were obtained from The Cancer Genome Atlas and Gene Expression Omnibus, respectively. Common differentially expressed genes (DEGs) were identified based on sequencing and expression as given in the profiling dataset. Pathway enrichment analysis of the DEGs was performed using the Database for Annotation, Visualization, and Integrated Discovery. The protein-protein interaction network was established using the string online database in order to identify hub genes. Univariate and multivariable Cox regression analyses were used to screen prognostic DEGs and to construct a prognostic signature. Survival analysis based on the prognostic signature was performed on TCGA EC dataset. A total of 255 common DEGs were found and 11 hub genes (TOP2A, CDK1, CCNB1, CCNB2, AURKA, PCNA, CCNA2, BIRC5, NDC80, CDC20, and BUB1BA) that may be closely related to the pathogenesis of EC were identified. A panel of 7 DEG signatures consisting of PHLDA2, GGH, ESPL1, FAM184A, KIAA1644, ESPL1, and TRPM4 were constructed. The signature performed well for prognosis prediction (p < 0.001) and time-dependent receiver-operating characteristic (ROC) analysis displayed an area under the curve (AUC) of 0.797, 0.734, 0.729, and 0.647 for 1, 3, 5, and 10-year overall survival (OS) prediction, respectively.

Conclusion

This study identified potential genes that may be involved in the pathophysiology of EC and constructed a novel gene expression signature for EC risk stratification and prognosis prediction.

A Novel Approach to Preoperative Risk Stratification in Endometrial Cancer: The Added Value of Immunohistochemical Markers

Background: The current model used to preoperatively stratify endometrial cancer (EC) patients into low- and high-risk groups is based on histotype, grade, and imaging method and is not optimal. Our study aims to prove whether a new model incorporating immunohistochemical markers, L1CAM, ER, PR, p53, obtained from preoperative biopsy could help refine stratification and thus the choice of adequate surgical extent and appropriate adjuvant treatment.

Materials and Methods: The following data were prospectively collected from patients operated for EC from January 2016 through August 2018: age, pre- and post-operative histology, grade, lymphovascular space invasion, L1CAM, ER, PR, p53, imaging parameters obtained from ultrasound, CT chest/abdomen, final FIGO stage, and current decision model (based on histology, grade, imaging method).

Results: In total, 132 patients were enrolled. The current model revealed 48% sensitivity and 89% specificity for high-risk group determination. In myometrial invasion >50%, lower levels of ER (p = 0.024), PR (0.048), and higher levels of L1CAM (p = 0.001) were observed; in cervical involvement a higher expression of L1CAM (p = 0.001), lower PR (p = 0.014); in tumors with positive LVSI, higher L1CAM (p = 0.014); in cases with positive LN, lower expression of ER/PR (p < 0.001), higher L1CAM (p = 0.002) and frequent mutation of p53 (p = 0.008).

Cut-offs for determination of high-risk tumors were established: ER <78% (p = 0.001), PR <88% (p = 0.008), and L1CAM ≥4% (p < 0.001). The positive predictive values (PPV) for ER, PR, and L1CAM were 87% (60.8–96.5%), 63% (52.1–72.8%), 83% (70.5–90.8%); the negative predictive values (NPV) for each marker were as follows: 59% (54.5–63.4%), 65% (55.6–74.0%), and 77% (67.3–84.2%). Mutation of p53 revealed PPV 94% (67.4–99.1%) and NPV 61% (56.1–66.3%). When immunohistochemical markers were included into the current diagnostic model, sensitivity improved (48.4 vs. 75.8%, p < 0.001). PPV was similar for both methods, while NPV (i.e., the probability of extremely low risk in negative test cases) was improved (66 vs. 78.9%, p < 0.001).

Conclusion: We proved superiority of new proposed model using immunohistochemical markers over standard clinical practice and that new proposed model increases accuracy of prognosis prediction. We propose wider implementation and validation of the proposed model.

Current Practices in the Processing, Diagnosis, and Reporting of Endometrial Carcinoma: Results of a Web-based Survey by the International Society of Gynecological Pathologists (ISGyP)

There have been significant advances in our understanding of the biology and classification of endometrial carcinoma, over the last few years, and the new prediction models proposed for prognostication. To accurately diagnose and stage tumors and apply these prediction models, it is necessary that there be standardized processing of specimens, and a common understanding and usage of the diagnostic terminology of endometrial carcinoma. The International Society of Gynecological Pathologists embarked on an ambitious project to achieve this goal in 2015. An early step in the process was to collect baseline information on existing practices with regard to the processing, diagnosis, and reporting of endometrial carcinomas among the members of the society. This was carried out using a web-based survey comprising 112 questions. The results are presented herein and reveal areas of uniformity but also areas of substantial variation among pathologists. The results of the survey assisted in developing the subsequent recommendations that follow as separate articles in this issue of the journal with regard to processing, diagnosis, and reporting of endometrial carcinomas.

High-grade Endometrial Carcinomas: Morphologic and Immunohistochemical Features, Diagnostic Challenges and Recommendations

This review of challenging diagnostic issues concerning high-grade endometrial carcinomas is derived from the authors' review of the literature followed by discussions at the Endometrial Cancer Workshop sponsored by the International Society of Gynecological Pathologists in 2016. Recommendations presented are evidence-based, insofar as this is possible, given that the levels of evidence are weak or moderate due to small sample sizes and nonuniform diagnostic criteria used in many studies. High-grade endometrioid carcinomas include FIGO grade 3 endometrioid carcinomas, serous carcinomas, clear cell carcinomas, undifferentiated carcinomas, and carcinosarcomas. FIGO grade 3 endometrioid carcinoma is diagnosed when an endometrioid carcinoma exhibits >50% solid architecture (excluding squamous areas), or when an architecturally FIGO grade 2 endometrioid carcinoma exhibits marked cytologic atypia, provided that a glandular variant of serous carcinoma has been excluded. The most useful immunohistochemical studies to make the distinction between these 2 histotypes are p53, p16, DNA mismatch repair proteins, PTEN, and ARID1A. Endometrial clear cell carcinomas must display prototypical architectural and cytologic features for diagnosis. Immunohistochemical stains, including, Napsin A and p504s can be used as ancillary diagnostic tools; p53 expression is aberrant in a minority of clear cell carcinomas. Of note, clear cells are found in all types of high-grade endometrial carcinomas, leading to a tendency to overdiagnose clear cell carcinoma. Undifferentiated carcinoma (which when associated with a component of low-grade endometrioid carcinoma is termed "dedifferentiated carcinoma") is composed of sheets of monotonous, typically dyscohesive cells, which can have a rhabdoid appearance; they often exhibit limited expression of cytokeratins and epithelial membrane antigen, are usually negative for PAX8 and hormone receptors, lack membranous e-cadherin and commonly demonstrate loss of expression of DNA mismatch repair proteins and SWI-SNF chromatin remodeling proteins. Carcinosarcomas must show unequivocal morphologic evidence of malignant epithelial and mesenchymal differentiation.

Endometrial Carcinoma Diagnosis: Use of FIGO Grading and Genomic Subcategories in Clinical Practice: Recommendations of the International Society of Gynecological Pathologists

In this review, we sought to address 2 important issues in the diagnosis of endometrial carcinoma: how to grade endometrial endometrioid carcinomas and how to incorporate the 4 genomic subcategories of endometrial carcinoma, as identified through The Cancer Genome Atlas, into clinical practice. The current International Federation of Gynecology and Obstetrics grading scheme provides prognostic information that can be used to guide the extent of surgery and use of adjuvant chemotherapy or radiation therapy. We recommend moving toward a binary scheme to grade endometrial endometrioid carcinomas by considering International Federation of Gynecology and Obstetrics defined grades 1 and 2 tumors as "low grade" and grade 3 tumors as "high grade." The current evidence base does not support the use of a 3-tiered grading system, although this is considered standard by International Federation of Gynecology and Obstetrics, the American College of Obstetricians and Gynecologists, and the College of American Pathologists. As for the 4 genomic subtypes of endometrial carcinoma (copy number low/p53 wild-type, copy number high/p53 abnormal, polymerase E mutant, and mismatch repair deficient), which only recently have been identified, there is accumulating evidence showing these categories can be reproducibly diagnosed and accurately assessed based on biopsy/curettage specimens as well as hysterectomy specimens. Furthermore, this subclassification system can be adapted for current clinical practice and is of prognostic significance independent of conventional variables used for risk assessment in patients with endometrial carcinoma (eg, stage). It is too soon to recommend the routine use of genomic classification in this setting; however, with further evidence, this system may become the basis for the subclassification of all endometrial carcinomas, supplanting (partially or completely) histotype, and grade. These recommendations were developed from the International Society of Gynecological Pathologists Endometrial Carcinoma project.

Immunohistochemical Nuclear Expression of β-Catenin as a Surrogate of CTNNB1 Exon 3 Mutation in Endometrial Cancer

OBJECTIVES

CTNNB1 exon 3 mutations have shown independent prognostic value in endometrial cancer. We aimed to assess whether nuclear β-catenin expression is an accurate surrogate, as immunohistochemistry is cheaper, faster, and more widely applicable than sequencing.

METHODS

A systematic review was performed by searching electronic databases for all studies assessing the association between β-catenin immunohistochemical expression and CTNNB1 mutations. Meta-analysis of diagnostic accuracy was performed by calculating sensitivity, specificity, positive and negative likelihood ratios (LR+ and LR-), diagnostic odds ratio (DOR), and area under the curve (AUC) on summary receiver operating characteristic curves.

RESULTS

Fifteen observational studies with 1,158 endometrial carcinomas were included. Pooled estimates showed sensitivity = 0.88, specificity = 0.85, LR+ = 4.57, LR- = 0.20, DOR = 27.16, and high diagnostic accuracy (AUC = 0.91).

CONCLUSIONS

Nuclear expression of β-catenin is an accurate immunohistochemical surrogate of CTNNB1 exon 3 mutations and thus might be considered in the risk stratification of endometrial cancer.

Clinical consequences of upfront pathology review in the randomised PORTEC-3 trial for high-risk endometrial cancer

Background

In the PORTEC-3 trial, women with high-risk endometrial cancer (HR-EC) were randomised to receive pelvic radiotherapy (RT) with or without concurrent and adjuvant chemotherapy (two cycles of cisplatin 50 mg/m² in weeks 1 and 4 of RT, followed by four cycles of carboplatin AUC5 and paclitaxel 175 mg/m²). Pathology review was required before patient enrolment. The aim of this analysis was to evaluate the role of central pathology review before randomisation.

Patients and methods

A total of 1295 cases underwent pathology review to confirm HR-EC in the Netherlands (n = 395) and the UK (n = 900), and for 1226/1295 (95%) matching review and original reports were available. In total, 329 of these patients were enrolled in the PORTEC-3 trial: 145 in the Netherlands and 184 in the UK, comprising 48% of the total PORTEC-3 cohort of 686 participants. Areas of discrepancies were evaluated, and inter-observer agreement between original and review opinion was evaluated by calculating the kappa value (κ).

Results

In the 1226 pathology reviews, 6356 selected items were evaluable for both original and review pathology. In 43% of cases at least one pathology item changed after review. For 102 patients (8%), this discrepancy led to ineligibility for the PORTEC-3 trial, most frequently due to differences in the assessment of histological type (34%), endocervical stromal involvement (27%) and histological grade (19%). Lowest inter-observer agreement was found for histological type (κ = 0.72), lymph-vascular space invasion (κ = 0.72) and histological grade (κ = 0.70).

Conclusion

Central pathology review by expert gynaeco-pathologists changed histological type, grade or other items in 43% of women with HR-EC, leading to ineligibility for the PORTEC-3 trial in 8%. Upfront pathology review is essential to ensure enrolment of the target trial-population, and to avoid over- or undertreatment, especially when treatment modalities with substantial toxicity are involved.

This study is registered with ISRCTN (ISRCTN14387080, www.controlled-trials.com) and with ClinicalTrials.gov (NCT00411138).

Targeting P16INK4A in uterine serous carcinoma through inhibition of histone demethylation

Uterine serous carcinoma (USC) is a subtype of endometrial cancer. Compared with endometrial endometroid carcinoma, the majority of USC cases are more aggressive. Cyclin-dependent kinase inhibitor 2A (P16INK4A) is a canonical tumor suppressor that blocks cell cycle progression; however, P16INK4A is overexpressed in USC. The aim of the present study was to determine the role of P16INK4A in P16INK4A‑positive endometrial cancer, with the hope of elucidating a novel therapeutic approach for this type of malignancy. A total of 2 endometrial cancer cell lines, ETN‑1 and EFE‑184, were selected for further investigation, due to them being known to express high levels of P16INK4A. Using short hairpin RNA targeting P16INK4A, P16INK4A was downregulated in these cancer cell lines. Cell viability and migration were examined via 2D/3D clonogenic and wound healing assays. Subsequently, GSK‑J4, a histone demethylase inhibitor, was employed to deplete P16INK4A in these cancer cell lines and an ex vivo culture system of a patient‑derived xenograft (PDX) endometrial tumor sample. Following P16INK4A knockdown, the proliferation and migration of ETN‑1 and EFE‑184 cells markedly declined. When exposed to GSK‑J4, the levels of KDM6B and P16INK4A were almost completely abrogated, and the cell viability was significantly reduced in these cell lines and the ex vivo‑cultured PDX tumor explants. The association between the levels of P16INK4A, lysine demethylase 6B (KDM6B) and the methylation status of histone 3 lysine 27 (H3K27) in these cell lines and the human USC tumor sample was also demonstrated. P16INK4A appears to be oncogenic in a number of endometrial cancer cell lines. The level of P16INK4A is associated with the methylation status of H3K27. Increased methylation of H3K27 coexists with downregulation of KDM6B and, subsequently, P16INK4A, which reduces cell proliferation and invasiveness in endometrial cancer. The observations of the present study may enable the development of a novel therapeutic strategy for P16INK4A‑positive endometrial cancer, particularly USC.

Gynecologic Cancers: Molecular Updates 2018

Ovarian carcinoma continues to be a concern for woman and maintains significant morbidity and mortality. Emerging molecular markers are providing additional opportunities for effective diagnosis and prognosis of disease. An integrated clinicopathologic and molecular classification of gynecologic malignancies has the potential to refine the clinical risk prediction of patients with cancer and to provide more tailored treatment recommendations.