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

The prognostic implication of polymerase epsilon-mutated endometrial cancer

The traditional classification and risk stratification systems of endometrial cancer (EC), which relied on histomorphological features, were limited and poor reproducible. The classification of new molecular subtypes of EC has been developing, including The Cancer Genome Atlas (TCGA)-four molecular subtypes: Polymerase epsilon (POLE) mutation (POLEmut), microsatellite instability hypermutated, copy number-low, and copy number-high and ProMisE-four molecular subtypes: POLEmut, mismatch repair deficiency, no specific molecular profile, and p53 abnormal. POLEmut usually correlates with a favorable outcome. Hence, we reviewed the research since the TCGA molecular subtypes developed in 2013 and summarized the characteristics and prognosis of POLEmut EC patients. In summary, we found POLEmut occurs in 7.3%-9.6% of EC in the previous studies. POLEmut EC consistently exhibits favorable patient outcomes, regardless of adjuvant therapy. The research of POLEmut in EC is absent in Taiwan, and the underlying mechanisms and cost-effectiveness need further investigation.

Comprehensive Review of Endometrial Cancer: New Molecular and FIGO Classification and Recent Treatment Changes

Endometrial cancer (EC) is the most common gynecologic malignancy in developed countries, with rising incidence due to aging populations and obesity-related factors. This review explores the evolving molecular and FIGO classifications of EC, highlighting their significance in diagnosis, prognosis, and personalized treatment strategies. Molecular subtyping based on The Cancer Genome Atlas (TCGA) classification offers a more precise understanding of EC, dividing it into POLE ultramutated, microsatellite instability-high (MSI-H), copy-number low (CNL), and copy-number high (CNH) subtypes. Each subgroup has distinct genetic, histological, and prognostic characteristics. Recent updates to the FIGO staging system incorporate molecular features, allowing for more tailored treatment approaches. Advances in immunotherapy, targeted therapies, and novel therapeutic combinations have reshaped clinical management. This review emphasizes the integration of molecular diagnostics into routine practice, outlining challenges and future perspectives in managing EC for improved patient outcomes.

High-grade corded and hyalinized endometrioid carcinoma of "no specific molecular profile": report of two cases

High-grade corded and hyalinized endometrioid carcinoma (CHEC) is an uncommon endometrial carcinoma variant which may mimic carcinosarcoma or dedifferentiated carcinoma and has shown association with mismatch repair deficiency (MMRd) and p53 abnormalities. Herein, we expand the spectrum of high-grade CHEC by presenting two cases showing a "no specific molecular profile" (NSMP). Case #1 was a 6-cm endometrial mass in a 25-year-old woman, infiltrating the deep myometrium and cervical stroma, with diffuse lymphovascular space invasion. Case #2 was an advanced, unresectable endometrial carcinoma involving the lower third of the vagina in an 81-year-old woman. On the endometrial biopsy specimen, both cases showed a markedly atypical and mitotically active corded component merging with a FIGO G3 endometrioid component and accompanied by squamous/morular differentiation. Both tumors showed nuclear β-catenin accumulation, retained MMR protein expression, wild-type p53 pattern, and no POLE mutations.

The corded component was absent in the hysterectomy specimen of case #1 and in the vaginal biopsy specimen of case #2. The present cases confirm the clinical and molecular heterogeneity of high-grade CHEC, including a wide age range at presentation, variable prognosis, and variable molecular background. Nonetheless, these cases retain unique features that support their distinction from carcinosarcoma and dedifferentiated carcinoma. We suggest to consider them as a variant of FIGO G3 endometrioid carcinoma. Further studies are necessary in this field.

Abnormal p53 High-Grade Endometrioid Endometrial Cancer: A Systematic Review and Meta-Analysis

OBJECTIVE

Our primary objective was to evaluate the oncologic outcomes of patients with abnormal p53 FIGO grade 3 (high-grade) endometrioid endometrial cancer. As secondary objectives, we determined the global prevalence of abnormal p53 in grade 3 endometrioid endometrial carcinomas and the geographical variations.

METHODS

The following electronic databases were searched: PubMed/Medline, EMBASE, Cochrane Library, Scopus, and Web of Science. We followed the Meta-Analysis for Observational Studies in Epidemiology guidelines and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. This review was preregistered with PROSPERO (no: CRD42023495192). Bias was assessed using the Quality in Prognosis Studies tool. For time-to-event data, the effect of p53 status on grade 3 endometrial cancer was described using hazard ratios (HRs) and corresponding 95% confidence intervals (CIs). Overall survival and progression-free survival were analyzed using one- and two-stage approaches, the Kaplan-Meier method, and Cox proportional hazards models.

RESULTS

Fifty-seven studies with 2528 patients were included. Patients with abnormal p53 had an increased risk of death (HR, 1.29 (95% CI, 1.11-1.48); I2 = 88%) and disease progression (HR, 1.63; 95% CI, 1.42-1.88; I2 = 2%) compared with patients with wildtype p53 G3 endometrial cancer. The global pooled prevalence of abnormal p53 was 30% (95% CI, 25-34%; tau2 = 0.02; I2 = 74%), with the highest prevalence being found in studies conducted in Asia (95% CI, 27-41%; tau2 = 0.01; I2 = 52%).

CONCLUSIONS

Abnormal p53 grade 3 endometrioid endometrial cancer is more common in Asia, and it is associated with decreased overall survival and progression-free survival.

Morphomolecular Correlation and Clinicopathologic Analysis in Endometrial Carcinoma

Research groups have identified 4 groups [polymerase epsilon (POLE) mutant, mismatch repair-deficient, p53-abnormal, and no specific molecular profile)] reflecting the Tumor Cancer Genomic Atlas Research Network subgroups in endometrial carcinomas, improving the clinical applicability of molecular classification. We have analyzed the histopathologic and prognostic characteristics of our cases based on the ProMisE classification, supported by growing data on recommended treatment regimens. The study included 118 cases of endometrial carcinoma diagnosed between 2016 and 2020, which underwent mismatch repair and p53 immunohistochemistry. Next-generation sequencing was performed for POLE mutation analysis, dividing the cases into 4 subgroups. The histopathologic and clinical characteristics of these groups were then analyzed statistically. Four cases(3.4%) were classified as POLE mutant, 31 (26.3%) as mismatch repair-deficient, 22 (18.6%) as p53 mutant, and 61 (51.7%) as no specific molecular profile. We categorized 118 patients with endometrial carcinoma into low (n=43), intermediate (n=28), high-intermediate (n=21), high (n=22), and advanced metastatic (n=4) risk groups regardless of the molecular subtypes of their disease. When we reclassified all cases according to the molecular subtypes of endometrial carcinoma only the risk group of 3 (2.5%) cases changed. Using the new algorithm we designed, after narrowing down the number of patients, the microcystic, elongated, and fragmented pattern of invasion was revealed as an independent prognostic factor that reduces overall survival time (hazard ratio: 16.395, 95% CI: 2.140-125.606, P =0.007). In conclusion, using the new algorithm we have designed, and by identifying patients for whom molecular classification could alter risk groups, we observed that molecular tests can be utilized more efficiently in populations with limited economic resources and, in doing so, we discovered a new morphologic marker with prognostic significance.

Molecular classification of metastatic and recurrent endometrial endometrioid carcinoma: prognostic relevance among low- and high-stage tumours

AIMS

Molecular classification according to The Cancer Genome Atlas (TCGA) improves endometrial endometrioid carcinoma (EEC) prognostication and has specific treatment implications; however, original data were skewed towards low-grade and low-stage tumours. Herein, we molecularly classify EECs metastatic at the time of diagnosis or with subsequently documented recurrent/metastatic disease to examine correlation with clinical outcomes.

METHODS

TCGA categories include POLE-mutated, microsatellite instability (MSI), p53 abnormal (p53 abnl) and no specific molecular profile (NSMP). POLE targeted sequencing at exons 9, 11, 13 and 14 and immunohistochemistry (IHC) for PMS2, MSH6 and p53 were performed to establish molecular classification.

RESULTS

The distribution in our cohort of 141 EECs was similar to that generally reported in EEC, with nine POLE-mutated (6%), 45 MSI (32%), 16 p53 abnl (11%) and 71 NSMP (50%), with similar distributions between low- and high-stage cohorts. We demonstrate that when stratified by molecular subtype, disease-specific survival from the time of high-stage (stages III-IV) presentation or time of recurrence in low-stage (stages I-II) disease among metastatic and/or recurrent EEC is strongly associated with TCGA classification (high-stage P = 0.02, low-stage P = 0.017). Discordant molecular classification between primary and metastatic/recurrent tumours occurred in four of 105 (3.8%) patients, two related to PMS2/MSH6 IHC and two related to p53 IHC.

CONCLUSIONS

We demonstrate that molecular classification is prognostically relevant not only at the time of diagnosis, but also at the time of recurrence and in the metastatic setting. Rare subclonal alterations occur and suggest a role for confirming TCGA classification in recurrent/metastatic tumours.

New clinicopathological concept of endometrial carcinoma with integration of histological features and molecular profiles

The dual-stratified pathway of endometrial carcinomas (ECs) has long been dominant. However, in 2013, The Cancer Genome Atlas (TCGA) defined four EC subgroups with distinctive prognoses. Inspired by TCGA, in 2018, the Proactive Molecular Risk Classifier for Endometrial Cancer (ProMisE) provided four pragmatic molecular classifiers to apply surrogate immunohistochemical markers to TCGA subgroup categorization. These trends prompted the revision of 2020 WHO Classification of Female Genital Tumors, 5th edition (2020 WHO classification), in which four molecular subtypes are recognized: POLE-ultramutated; mismatch repair-deficient; p53-mutant; and no specific molecular profile. In the 2020 WHO classification, the diagnostic algorithm is characterized by prioritizing POLEmut over other molecular abnormalities. Following the 2020 WHO classification, Federation of International Gynecology and Obstetrics (FIGO) proposed a new staging system in 2023. The updated system focuses on diagnostic parameters, such as histological type and grade, lymphovascular space invasion, and molecular alterations. These new histomolecular diagnostic concepts of ECs are being accordingly introduced into the routine pathology practice. For the first time, the 2020 WHO classification includes mesonephric-like adenocarcinoma (MLA) as a novel histological entity, mimicking the conventional mesonephric adenocarcinoma, but is considered of Müllerian ductal origin.

Molecular Classification Outperforms Histologic Classification in Prognostication of High-grade Endometrial Carcinomas With Undifferentiated and Sarcomatous Components

Since the establishment of 4 molecular subgroups of endometrial carcinoma (EC), there has been significant interest in understanding molecular classification in the context of histologic features and diagnoses. ECs with undifferentiated, spindle, and/or sarcomatous components represent a diagnostically challenging subset of tumors with overlapping clinical and histologic features. We examined the clinicopathologic, morphologic, immunohistochemical, and molecular features of these tumors identified in our institutions' pathology databases using immunohistochemistry and targeted sequencing. Disease-specific survival (DSS) and progression-free survival (PFS) were analyzed using Kaplan-Meier curves and log-rank tests. One hundred sixty-two ECs were included: carcinosarcomas (UCS; n=96), dedifferentiated/undifferentiated EC (DDEC/UDEC; n=49), and grade 3 endometrioid EC with spindled growth (GR3spEEC) (n=17). All molecular subgroups were represented in all histologic subtypes and included 12 (7%) POLE -mutated ( POLE mut), 43 (27%) mismatch repair-deficient (MMRd), 77 (48%) p53-abnormal (p53abn), and 30 (19%) no specific molecular profile (NSMP) tumors. However, the molecular classification (irrespective of histologic diagnosis) was a significant predictor for both DSS ( P =0.008) and P≤0.0001). POLE mut EC showed an excellent prognosis with no recurrences or deaths from the disease. MMRd tumors also showed better outcomes relative to NSMP and p53abn tumors. In conclusion, molecular classification provides better prognostic information than histologic diagnosis for high-grade EC with undifferentiated and sarcomatous components. Our study strongly supports routine molecular classification of these tumors, with emphasis on molecular group, rather than histologic subtyping, in providing prognostication.

Evaluation of prognostic potential of β-catenin and L1CAM expression according to endometrial cancer risk group

OBJECTIVE

We investigate the prognostic role of β-catenin and L1 neuronal cell-adhesion molecule (L1CAM) according to risk groups in endometrial carcinomas (EC).

METHODS

A total of 335 EC patients were classified according to the Proactive Molecular Risk Classifier for Endometrial Cancer. We evaluated the expression of ß-catenin and L1CAM using immunohistochemistry, and their association with clinicopathological characteristics and survival.

RESULTS

The expressions of β-catenin and L1CAM were observed in 10.4% of all patients, respectively, and showed mutually exclusive pattern. While β-catenin expression was associated with endometrioid histology (p = 0.035) and low tumor grade (p = 0.045), L1CAM expression was associated with non-endometrioid histology (p < 0.001), high tumor grade (p < 0.001), lymphovascular space invasion (p = 0.006), and advanced International Federation of Gynecology and Obstetrics (FIGO) stage (p = 0.001). β-catenin expression was most frequent in the no specific molecular (NSMP) group (26/35, 74.3%), followed by the DNA polymerase-ε-mutated (POLE-mut) (6/35, 17.1%), and mismatch repair-deficiency (dMMR) (3/35, 8.6%). L1CAM expression was most frequent in the p53-abnormal group (22/35, 62.9%), followed by the NSMP (6/35, 17.1%), dMMR (4/35, 11.4%), and POLE-mut (3/35, 8.6%). Although both markers did not show statistical significance in multivariate analysis for both progression-free survival (PFS) and overall survival in entire cohort, β-catenin positivity was identified as the sole factor associated with worse PFS in the high-intermediate risk subgroup (p = 0.001).

CONCLUSION

The expression of nuclear β-catenin may serve as a potential biomarker for predicting recurrence and guiding therapeutic strategies in high-intermediate risk EC patients.

Special Considerations in Classification and Workup of Endometrial Carcinomas

CONTEXT.—

A variety of uncommon malignant endometrial tumors can be challenging to diagnose because of overlapping morphology with more common entities. In some cases, immunohistochemical stains and/or molecular testing allow for more definitive diagnosis or prognostication.

OBJECTIVE.—

To review classic morphologic features of uncommon endometrial tumors, pathologic features of these tumors and their mimics, and the evidence for use of immunohistochemistry and molecular testing in the diagnosis of these tumors.

DATA SOURCES.—

University of Michigan (Ann Arbor) cases and review of pertinent literature about each entity.

CONCLUSIONS.—

Although each of these uncommon endometrial tumors has morphologic mimics, key histologic features, immunohistochemical stains, and molecular testing allow for accurate classification.

Prognosis of polymerase epsilon (POLE) mutation in high-grade endometrioid endometrial cancer: Systematic review and meta-analysis

BACKGROUND

POLE mutated endometrial carcinomas may represent a subspecific type of tumors harboring a more favorable prognosis. Grade 3 (G3 or high-grade) endometrioid endometrial carcinomas remain a clinical dilemma, with some tumors behaving as the low-grade counterparts and others presenting a more aggressive behavior.

OBJECTIVES

To determine the association between POLE mutational status and the overall-survival (OS) and progression-free-survival (PFS) of patients with G3 endometrioid endometrial cancer (EC). We also aimed to determine the prevalence of POLE mutations in G3 endometrioid EC.

METHODS

We conducted a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (PROSPERO No: CRD4202340008). We searched the following electronic databases: PubMed/Medline, EMBASE, Cochrane Library, Scopus, and Web of Science. For time-to-event data, the effect of POLE mutation in G3 EC was described using hazard ratios (HRs) and corresponding 95% confidence intervals (CIs). Individual patient data for each study was investigated if available from the study authors. If individual patient data were not available, information regarding time-to-event outcomes was extracted using an appropriate methodology. OS and PFS were analyzed using both one-stage and two-stage approaches, the Kaplan-Meier method, and Cox-proportional hazards models.

RESULTS

This systematic review and meta-analysis included 19 studies with 3092 patients who had high-grade endometrioid EC. Patients with POLE mutations had lower risks of death (HR = 0.36, 95% CI 0.26 to 0.50, I2 = 0%, 10 trials) and disease progression (HR = 0.31, 95% CI 0.17 to 0.57, I2 = 33%, 10 trials). The pooled prevalence of POLE mutation was 11% (95% CI 9 to 13, I2 = 68%, 18 studies).

CONCLUSION

POLE mutations in high-grade endometrioid EC are associated with a more favorable prognosis with increased OS and PFS.

Clinicopathological characteristics of multiple-classifier endometrial cancers: a cohort study and systematic review

BACKGROUND

Endometrial cancers with more than one molecular feature-POLE mutations (POLEmut), mismatch repair protein deficiency (MMRd), p53 abnormality (p53abn)-are called 'multiple classifiers'.

OBJECTIVE

To describe our cohort of multiple classifiers and to report the results of a review on their incidence and the techniques used to identify them.

METHODS

Multiple classifiers identified at the European Institute of Oncology, Milan, between April 2019 and Decmber 2022, were included. Clinicopathological, molecular characteristics, and oncologic outcomes were summarized and compared between single and multiple classifiers sharing common features. Studies on molecular classification of endometrial cancer were searched in the PubMed Database to collect data on the incidence of multiple classifiers and the techniques used for classification.

RESULTS

Among 422 patients, 48 (11.4%) were multiple classifiers: 15 (3.6%) POLEmut-p53abn, 2 (0.5%) POLEmut-MMRd, 28 (6.6%) MMRd-p53abn, and 3 (0.7%) POLEmut-MMRd-p53abn. MMRd-p53abn and MMRd differed in histotype (non-endometrioid: 14.8% vs 2.0%, p=0.006), grade (high-grade: 55.6% vs 22.2%, p=0.001), and MMR proteins expression, whereas they differed from p53abn in histotype (non-endometrioid: 14.8% vs 50.0%, p=0.006). POLEmut-p53abn and POLEmut differed only in grade (high-grade: 66.7% vs 22.7%, p=0.008), while they differed from p53abn in age (56.1 vs 66.7 years, p=0.003), stage (advanced: 6.7% vs 53.4%, p=0.001), and histotype (non-endometrioid: 6.7% vs 50.0%, p=0.002). Two (7.1%) patients with MMRd-p53abn, 4 (4.0%) with MMRd, and 25 (34.3%) with p53abn had a recurrence. No recurrences were observed in POLEmut-p53abn and POLEmut. TP53 sequencing allowed the detection of additional 7 (18.9%) multiple classifiers with normal p53 immunostaining. The incidence of multiple classifiers ranged from 1.8% to 9.8% in 10 published studies including >100 patients. When only p53 immunohistochemistry was performed, the highest incidence was 3.9%.

CONCLUSIONS

The characteristics of POLEmut-p53abn resembled those of POLEmut, whereas MMRd-p53abn appeared to be intermediate between MMRd and p53abn. The high proportion of multiple classifiers may be related to the methods used for molecular classification, which included both p53 immunohistochemistry and TP53 sequencing.

Mismatch Repair Deficiency as a Predictive and Prognostic Biomarker in Endometrial Cancer: A Review on Immunohistochemistry Staining Patterns and Clinical Implications

Among the four endometrial cancer (EC) TCGA molecular groups, the MSI/hypermutated group represents an important percentage of tumors (30%), including different histotypes, and generally confers an intermediate prognosis for affected women, also providing new immunotherapeutic strategies. Immunohistochemistry for MMR proteins (MLH1, MSH2, MSH6 and PMS2) has become the optimal diagnostic MSI surrogate worldwide. This review aims to provide state-of-the-art knowledge on MMR deficiency/MSI in EC and to clarify the pathological assessment, interpretation pitfalls and reporting of MMR status.

FIGO 2023 endometrial cancer staging: too much, too soon?

An updated International Federation of Gynecology and Obstetrics (FIGO) staging system for endometrial carcinoma was introduced in June 2023. The new system represents a significant departure from traditional endometrial and other gynecological carcinoma staging systems which are agnostic of parameters such as tumor type, tumor grade, lymphovascular space invasion, and molecular alterations. The updated system, which incorporates all of these 'non-anatomical' parameters, is an attempt to make staging more personalized and relevant to patient prognostication and management, and to align with the European Society of Gynaecological Oncology/European Society for Radiotherapy and Oncology/European Society of Pathology (ESGO/ESTRO/ESP) risk stratification. Herein, we present a critical review of the new staging system and discuss its advantages and disadvantages. The authors propose that the new FIGO staging system should be first appraised at a multi-institutional and global level with the input of all relevant societies (gynecology, pathology, gynecologic oncology, medical oncology, radiation oncology) to understand the impact, scope, and supporting evidence of the proposed changes. Such a process is fundamental to produce a robust system that pathologists and treating clinicians can adopt.

Evaluation of Lineage/Site-specific Nuclear Immunohistochemical Markers SATB2, Cyclin D1, SALL4, and BCOR in High-grade Endometrial Carcinomas

Poorly differentiated malignant neoplasms involving the gynecologic tract routinely include a poorly differentiated endometrial carcinoma (EC) in the differential diagnosis. Some nuclear lineage/site-specific immunohistochemical markers are utilized in this diagnostic setting including SATB2, cyclin D1, SALL4, and BCOR, but their specificity and use in small samples are not clear across the spectrum of ECs. Cases of undifferentiated/dedifferentiated endometrial carcinomas (UEC/DDEC), clear cell carcinoma (CCC), uterine serous carcinoma (USC), FIGO grade 3 endometrial endometrioid carcinoma (EEC), and uterine carcinosarcoma (UCS) were identified and diagnoses confirmed. Whole-section immunohistochemical stains for SATB2, cyclin D1, SALL4, BCOR, and PAX8 were performed. A total of 113 cases were utilized: 15 CCC, 26 EEC, 19 UCS, 22 USC, and 31 UEC/DDEC. Cases were distributed across both low (49%) and high (51%) FIGO clinical stages. SATB2 was expressed by UCS (8/19, 42%), EEC (10/26, 38%), UEC/DDEC (11/30, 37%), and USC (6/22, 27%). Cyclin D1 was expressed by EEC (24/26, 92%), USC (17/22, 77%), UEC/DDEC (15/20 EEC component, 75%; 22/30 UEC, 73%), UCS (10/16 carcinoma, 63%; 11/19 sarcoma, 58%), and CCC (8/15, 53%). SALL4 was expressed most frequently by UEC/DDEC (12/30, 40%), but also USC (7/22, 32%), EEC (5/26, 19%), and UCS (4/16 carcinoma, 25%; 3/19 sarcoma, 16%). BCOR was expressed at low levels in 2 USC, 2 UEC/DDEC, and 2 UCS. PAX8 was generally positive but showed lower expression in UEC/DDEC (17/30, 57%) and in the sarcomatous portions of UCS (6/19, 32%). SATB2, cyclin D1, SALL4, and BCOR stain variable numbers of poorly-differentiated EC and must be carefully interpreted within morphologic and clinical context.

Adjuvant radiation therapy in early-stage endometrial cancer with abnormal beta-catenin expression is associated with improved local control

OBJECTIVES

Emerging data suggests that abnormal (nuclear) β-catenin expression in some settings is associated with poorer outcomes. Our study aimed to verify the significance of abnormal β-catenin expression in early-stage endometrial cancer patients and determine if adjuvant radiation therapy (RT) improves local control.

METHODS

We identified 213 patients with FIGO 2018 stage I-II endometrioid endometrial cancer who underwent surgery from 2009 to 2021 with β-catenin expression assessed. Vaginal, regional, and distant recurrences were analyzed using competing risk methods, and overall survival was analyzed using Kaplan-Meier.

RESULTS

Median follow up was 53.2 months; 6.9% experienced vaginal, 8.2% regional, and 7.4% distant recurrence. For the entire cohort, abnormal β-catenin expression was significantly associated with vaginal recurrence and remained significant on multivariate analysis (p = 0.03). There were 114 patients in the no specific molecular profile (NSMP) subgroup, and abnormal β-catenin expression was present in 46.5%. In the NSMP subgroup, abnormal β-catenin expression was associated with increased rates of vaginal recurrence (p = 0.06). Abnormal β-catenin expression in the NSMP subgroup was significant on multivariate analysis for vaginal recurrence (p = 0.04). RT significantly decreased vaginal recurrences in the entire cohort in patients with abnormal β-catenin expression (0%) versus wild type expression (17.5%; p = 0.03). In the NSMP subgroup 0% of patients who received RT versus 20.9% of patients who did not receive RT experienced a vaginal recurrence (p = 0.03).

CONCLUSION

Use of adjuvant RT for stage I-II NSMP endometrial cancer with abnormal β-catenin expression improved local control. RT should be considered in these patients to decrease risk of vaginal recurrences.

HER2 IHC Expression and Gene Amplification in p53-aberrant High-grade Endometrial Endometrioid Carcinoma Suggests That This Population May Benefit From HER2 Testing and Targeted Therapy

Among gynecologic cancers, uterine serous carcinoma (USC) has been shown to be human epidermal growth factor receptor 2 (HER2) amplified and trastuzumab has been included in the recent National Comprehensive Cancer Network (NCCN) guidelines for treatment of advanced stage or recurrent USC with HER2 overexpression/amplification. There is limited literature suggesting that a subset of high-grade endometrioid carcinomas with aberrant p53 expression may also be HER2 amplified and these patients could benefit from the addition of targeted therapy. We identified 59 p53-aberrant (mismatch repair proficient) FIGO 3 endometrioid carcinomas of the uterus. HER2 immunohistochemistry was performed in all 59 tumors and HER2 fluorescence in situ hybridization (FISH) was performed in 52 of the 59 cases. Four of the 59 cases were HER2 3+ by immunohistochemistry (6.7%), using the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) 2007, 2013, and 2018 criteria. HER2 FISH was performed in 3 of the 4 cases and was amplified in all 3. Nine, 8, and 7 tumors showed 2+ HER2 staining when applying 2018, 2013, and 2007 criteria, respectively, FISH was performed in 7 tumors and none were amplified. An additional 4 cases did not perfectly meet the 2018 ASCO/CAP criteria but were assigned a score of 2+, none were amplified by HER2 FISH. The remaining 42 cases showed 1+ or no staining for HER2, FISH was successfully performed in 38 tumors and none showed amplification. Approximately half of the tumors fulfilled criteria for HER2-low or HER2-very low (10 HER2-low and 20 HER2-very low). Our data shows that a subset of p53-aberrant high-grade endometrial endometrioid carcinoma express HER2 and these patients may benefit from the addition of targeted therapy. The role of targeted therapy in HER2-low gynecologic carcinoma is currently unexplored.

Incorporating Molecular Classification When Stratifying the Survival Risk of Patients with High-Grade Endometrial Carcinomas

Assessing survival risk in patients with high-grade endometrial carcinomas has remained challenging. We aimed to investigate the distribution of molecular subtypes and assess their prognostic role in a large cohort of 355 patients with high-grade endometrial carcinoma. Molecular classification was determined using DNA polymerase epsilon (POLE) sequencing as well as immunohistochemical staining for p53 and mismatch repair (MMR) proteins. Endometrial carcinomas were stratified into four subtypes: POLE ultramutated, MMR-deficient, non-specific molecular profile (NSMP), and p53-mutant. This study included 177 and 178 patients with endometrioid and non-endometrioid carcinomas, respectively. Forty-two patients (11.8%) were categorized as POLE ultramutated, 106 (29.9%) as MMR-deficient, 128 (36.1%) as p53-mutant, and 79 (22.2%) as NSMP. Patients of different molecular subtypes had distinct survival times; molecular classification, but not histotype, was significantly associated with survival outcomes. When incorporating molecular classification into the stratification model, 52 patients (15.5%) switched risk groups, with 40 (11.9%) shifting to a lower risk for having a POLE mutation and 12 (3.6%) shifting to a higher risk owing to p53-mutant status. Molecular classification may provide more accurate prognostic information among patients with high-grade endometrial carcinomas and improve their stratification for purposes of clinical management.

Clinicopathologic Evaluation of CTNNB1 Mutations in High-Intermediate Risk Endometrial Endometrioid Carcinoma

CTNNB1 mutations convey increased risk of recurrence in low-risk endometrial endometrioid carcinoma (EEC). Results from previous high-intermediate risk (HIR) cohorts are mixed. The aims of this study were to correlate CTNNB1 mutational status with clinical outcomes and to evaluate the relationship between CTNNB1 mutations and the 4 prognostic subgroups defined by The Cancer Genome Atlas in HIR EEC. CTNNB1 mutational status was determined by Sanger sequencing of exon 3 of the CTNNB1 gene. Mismatch repair, POLE , p53, and L1 cell-adhesion molecule (L1CAM) status were also evaluated. Descriptive statistics and survival analyses were performed. Eighty-eight cases of HIR EEC were identified, of which 22 (25%) were CTNNB1 mutant ( CTNNB1 -mut) and 66 (75%) were wild-type ( CTNNB1 -WT). Median follow-up was 60 mo. Recurrence occurred in 13/88 (15%) patients. Recurrence rates were not significantly different between patients with CTNNB1- mut and CTNNB1- WT tumors (14% vs. 15%, P =0.86). Recurrence-free survival and overall survival were not significantly different (recurrence-free survival hazard ratio: 0.97, 95% confidence interval: 0.27-3.52, P =0.96; overall survival hazard ratio: 0.23, 95% confidence interval: 0.03-1.71, P =0.15). Mismatch repair deficiency was more prevalent in CTNNB1 -WT compared with CTNNB1 -mut tumors (46% vs. 14%, P =0.01); prevalence of POLE mutations and aberrant p53 were not significantly different. In contrast to patients with low-risk EEC, no differences in recurrence or survival were found in patients with HIR EEC with CTNNB1- mut compared with CTNNB1 -WT tumors.

Molecular Analysis of HPV-independent Primary Endometrial Squamous Cell Carcinoma Reveals TP53 and CDKN2A Comutations : A Clinicopathologic Analysis With Re-evaluation of Diagnostic Criteria

Human papillomavirus (HPV)-independent primary endometrial squamous cell carcinoma (PESCC) is a rare but aggressive subtype of endometrial carcinoma for which little is known about the genomic characteristics. Traditional criteria have restricted the diagnosis of PESCC to cases without any cervical involvement. However, given that modern ancillary techniques can detect HPV and characteristic genetic alterations that should identify the more common mimics in the differential diagnosis, including endometrial endometrioid carcinoma with extensive squamous differentiation and HPV-associated primary cervical squamous cell carcinoma, those criteria may benefit from revision. To further characterize PESCC, we identified 5 cases of pure squamous cell carcinoma dominantly involving the endometrium that had the potential to be PESCC: 1 case involving only the endometrium and 4 cases with some involvement of the cervix. Clinicopathologic features were assessed and immunohistochemical analysis (p16, estrogen receptor, progesterone receptor, and p53), HPV RNA in situ hybridization (high-risk and low-risk cocktails and targeted probes for 16 and 18), and molecular studies were performed. All tumors showed aberrant/mutation-type p53 expression, were negative for estrogen receptor, progesterone receptor, and p16, and had no detectable HPV. Per whole-exome sequencing, 4 of the 5 tumors demonstrated comutations in TP53 and CDKN2A (p16). Four patients died of disease within 20 months (range, 1 to 20 mo; mean, 9 mo), and 1 patient had no evidence of disease at 38 months. PESCC represents a unique, clinically aggressive subtype of endometrial cancer with TP53 and CDKN2A comutations. This characteristic profile, which is similar to HPV-independent squamous cell carcinoma of the vulva, is distinct from endometrioid carcinoma with extensive squamous differentiation and HPV-associated primary cervical squamous cell carcinoma and can be used to distinguish PESCC from those mimics even when cervical involvement is present. Diagnostic criteria for PESCC should be relaxed to allow for cervical involvement when other pathologic features are consistent with, and ancillary techniques are supportive of classification as such.

The clinicopathological characteristics of POLE-mutated/ultramutated endometrial carcinoma and prognostic value of POLE status: a meta-analysis based on 49 articles incorporating 12,120 patients

Objective

This study was designed to investigate the frequency and clinicopathological characteristics of POLE-mutated/ultramutated (POLEmut) in endometrial carcinoma (EC) and assess the prognostic values of POLE status.

Methods

Electronic databases were screened to identify relevant studies. Meta-analysis was used to yield the pooled frequency of POLEmut and prognostic parameters by 95% confidence interval (CI), odd ratio (OR), and hazard ratio (HR).

Results

Totally, 12,120 EC patients from 49 studies were included. The pooled frequency of POLEmut was 7.95% (95% CI: 6.52–9.51%) in EC, 7.95% (95% CI: 6.55–9.46%) in endometrioid endometrial carcinoma, and 4.45% (95% CI: 2.63–6.61%) in nonendometrioid endometrial carcinoma. A higher expression occurred in grade 3 (OR = 0.51, 95% CI: 0.36–0.73, P = 0.0002), FIGO stage I-II (OR = 1.91, 95% CI: 1.29–2.83, P = 0.0013), and myometrial invasion< 50% (OR = 0.66, 95% CI: 0.50–0.86, P = 0.0025). Survival analyses revealed favorable OS (HR = 0.68, 95% CI: 0.55–0.85, P = 0.0008), PFS (HR = 0.74, 95% CI: 0.59–0.93, P = 0.0085), DSS (HR = 0.61, 95% CI: 0.44–0.83, P = 0.0016), and RFS (HR = 0.47, 95% CI: 0.35–0.61, P <  0.0001) for POLEmut ECs. Additionally, the clinical outcomes of POLEmut group were the best, but those of p53-abnormal/mutated (p53abn) group were the worst, while those of microsatellite-instable (MSI)/hypermutated group and p53-wild-type (p53wt) group were medium.

Conclusions

The POLEmut emergered higher expression in ECs with grade 3, FIGO stage I-II, and myometrial invasion< 50%; it might serve as a highly favorable prognostic marker in EC; the clinical outcomes of POLEmut group were the best one among the four molecular subtypes.

HE4 Tissue Expression as A Putative Prognostic Marker in Low-Risk/Low-Grade Endometrioid Endometrial Cancer: A Review

Low-grade stage I endometrioid endometrial carcinomas should have an excellent prognosis, but a small subset of these cancers can relapse. The search for putative immunohistochemical prognostic markers for relapse in low-risk/low-grade endometrioid endometrial cancers remains open. Among the candidate molecules that may implicate the roles of immunohistochemical risk markers, we focused our attention on human epididymis protein 4 (HE4) after a review of the literature. Few authors have devoted themselves to this topic, and none have found a correlation between the tissue expression of HE4 and the molecular classification of endometrial cancer. Five different variants of HE4 mRNA and multiple protein isoforms of HE4 were identified many years ago, but current HE4 assays only measure the total HE4 expression and do not distinguish the different proteins encoded by different mRNA variants. It is important to have an approach to distinguish specific variants in the future.

TCGA Molecular Prognostic Groups of Endometrial Carcinoma: Current Knowledge and Future Perspectives

The four TCGA-based molecular prognostic groups of endometrial carcinoma (EC), i.e., POLE-mutant, mismatch repair (MMR)-deficient, p53-abnormal, and “no specific molecular profile” (NSMP), have recently been integrated into ESGO-ESTRO-ESP guidelines. The POLE-mutant and MMR-deficient groups are associated with high mutational load, morphological heterogeneity, and inflammatory infiltration. These groups are frequent in high-grade endometrioid, undifferentiated/dedifferentiated, and mixed histotypes. POLE-mutant ECs show good prognosis and do not require adjuvant treatment, although the management of cases at stage >II is still undefined. MMR-deficient ECs show intermediate prognosis and are currently substratified based on clinicopathological variables, some of which might not have prognostic value. These groups may benefit from immunotherapy. P53-mutant ECs are typically high-grade and often morphologically ambiguous, accounting for virtually all serous ECs, most carcinosarcomas and mixed ECs, and half of clear-cell ECs. They show poor prognosis and are treated with chemoradiotherapy; a subset may benefit from HER2 inhibitors or PARP inhibitors. The NSMP group is the most frequent TCGA group; its prognosis is highly variable and affected by clinicopathological/molecular factors, most of which are still under evaluation. In conclusion, the TCGA classification has improved diagnosis, risk stratification, and management of EC. Further studies are needed to resolve the points of uncertainty that still exist.

Endometrial carcinoma with diffuse melanocytic differentiation: Clinicopathological and molecular analysis of a case with literature review and focus on differential diagnosis

Herein, we present a clinicopathological and molecular analysis of a case of endometrial carcinoma with diffuse melanocytic differentiation with literature review. A 72-year-old woman underwent hysterectomy due to a 14 cm endometrial mass. On histology, the tumor showed a serous carcinoma component and a solid component with giant eosinophilic and dyshesive multinucleated cells. Differential diagnosis included several entities, such as undifferentiated giant cell carcinoma and carcinosarcoma with rhabdomyoblasts. The solid component showed diffuse positivity for cytokeratin AE1/AE3, Melan A, Cathepsin K and S100, focal HMB45 positivity and loss of e-cadherin. The tumor was p53-abnormal, mismatch repair-proficient and POLE-wild-type. The patient had extrauterine metastases and was alive with disease at 12 months. Previous cases of endometrial and ovarian carcinomas with melanocytic differentiation (n = 7) did not show giant bizarre cells but showed melanin production; all cases were advanced and/or had unfavorable outcomes. In conclusion, endometrial carcinomas with melanocytic differentiation are highly aggressive tumors which should be distinguished from other entities. Being aware of this entity may help not to miss it.

The Role of Immunohistochemistry Markers in Endometrial Cancer with Mismatch Repair Deficiency: A Systematic Review

The objective of this systematic review was to summarize our current knowledge of the role of immunohistochemistry (IHC) markers for identifying mismatch repair-deficient (MMRd) tumors in endometrial cancer (EC). Identification of MMRd tumors, which occur in 13% to 30% of all ECs, has become critical for patients with colorectal and endometrial cancer for therapeutic management, clinical decision making, and prognosis. This review was conducted by two authors applying the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using the following terms: “immunohistochemistry and microsatellite instability endometrial cancer” or “immunohistochemistry and mismatch repair endometrial cancer” or “immunohistochemistry and mismatch repair deficient endometrial cancer”. Among 596 retrieved studies, 161 fulfilled the inclusion criteria. Articles were classified and presented according to their interest for the diagnosis, prognosis, and theragnostics for patients with MMRd EC. We identified 10, 18, and 96 articles using IHC expression of two, three, or four proteins of the MMR system (MLH1, MSH2, MHS6, and PMS2), respectively. MLH1 promoter methylation was analyzed in 57 articles. Thirty-four articles classified MMRd tumors with IHC markers according to their prognosis in terms of recurrence-free survival (RFS), overall survival (OS), stage, grade, and lymph node invasion. Theragnostics were studied in eight articles underlying the important concentration of PD-L1 in MMRd EC. Even though the role of IHC has been challenged, it represents the most common, robust, and cheapest method for diagnosing MMRd tumors in EC and is a valuable tool for exploring novel biotherapies and treatment modalities.

Current Prognostic and Predictive Biomarkers for Endometrial Cancer in Clinical Practice: Recommendations/Proposal from the Italian Study Group

Endometrial carcinoma (EC) is the most common gynecological malignant disease in high-income countries, such as European countries and the USA. The 2020 edition of the World Health Organization (WHO) Classification of Tumors of the Female Genital Tract underlines the important clinical implications of the proposed new histomolecular classification system for ECs. In view of the substantial genetic and morphological heterogeneity in ECs, both classical pthological parameters and molecular classifiers have to be integrated in the pathology report. This review will focus on the most commonly adopted immunohistochemical and molecular biomarkers in daily clinical characterization of EC, referring to the most recent published recommendations, guidelines, and expert opinions.

Clinical impact of genetic alterations of CTNNB1 in patients with grade 3 endometrial endometrioid carcinoma

To identify prognostic factors in patients with grade 3 (high‐grade) endometrial endometrioid carcinoma, we evaluated the spectrum of genomic alterations and examined whether previously reported molecular subtypes of endometrial carcinoma were adapted to clinical outcome prediction. Seventy‐five Japanese patients with grade 3 endometrial endometrioid carcinoma, who underwent a potentially curative resection procedure between 1997 and 2018 at the National Cancer Center Hospital, were included. We classified the patients into four risk groups of the disease based on the Proactive Molecular Risk Classifier for Endometrial Cancer. Genomic alterations in PTEN, ARID1A, TP53, and PIK3CA were detected in more than 30% of the patients. Overall survival and recurrence‐free survival of patients with genomic alterations in CTNNB1 were poorer than those of patients with wild‐type CTNNB1 (p = 0.006 and p = 0.004, respectively). Compared with that of alterations prevalent in Caucasians, the frequency of genomic alterations in POLE and TP53 was higher in our study than in The Cancer Genome Atlas dataset (p = 0.01 and p = 0.01, respectively). The tendency for recurrence‐free survival in the POLE exonuclease domain mutation group was better than that in the TP53 mutation and mismatch repair‐deficient groups (p = 0.08 and p = 0.07, respectively), consistent with the Proactive Molecular Risk Classifier for Endometrial Cancer risk classifier definition. The CTNNB1 mutation is a potential novel biomarker for the prognosis of patients with grade 3 endometrial endometrioid carcinoma, and prognosis classification using Proactive Molecular Risk Classifier for Endometrial Cancer may help screen Japanese patients with the disease.

Clinicopathological Features Associated with Microsatellite Instability/Mismatch Repair Deficiency in Uterine Carcinosarcoma: A Quantitative Systematic Review

INTRODUCTION

Recent studies suggested that microsatellite instability/mismatch repair deficiency (MSI/MMR-d) might define a clinicopathologically distinct subset of uterine carcinosarcomas (UCSs).

OBJECTIVE

The aim of this study was to compare clinicopathological features between MSI/MMR-d and microsatellite-stable/mismatch repair-proficient (MSS/MMR-p) UCSs.

METHODS

A quantitative systematic review was performed by searching electronic databases from January 2000 to January 2021. All studies assessing MSI/MMR status in UCS were included. Odds ratio (OR) with a significant two-tailed p value <0.05 was used to assess the association of MSI/MMR-d with clinicopathological features.

RESULTS

Eleven studies with 783 patients were included. MSI/MMR-d was directly associated with endometrioid (pure: p < 0.001; pure + mixed: p < 0.001), undifferentiated/dedifferentiated (p < 0.001), and clear cell carcinoma component (p = 0.046), and inversely associated with age >60 (p = 0.034), serous carcinoma component (pure: p < 0.001; pure + mixed: p < 0.001), heterologous sarcoma component (p = 0.027), TP53-mutation/p53-abnormal expression (p < 0.001), and recurrence (p < 0.001). MSI/MMR-d showed no significant association with advanced FIGO stage (OR = 1.259; p = 0.517), low-grade carcinoma component (pure: p = 0.596; pure + mixed: p = 0.307), mixed carcinoma component (p = 1), and proportion of patients "dead of disease" (p = 0.352), "alive with disease" (p = 1) or with "no evidence of disease" (p = 0.458).

CONCLUSION

MSI/MMR-d UCSs show younger age, more common endometrioid, undifferentiated or clear cell carcinoma component, and less common serous carcinoma component, heterologous sarcoma component, and TP53 mutation than MSS/MMR-p UCSs. Given the discrepancy between recurrence rate and oncologic outcomes at the last follow-up, further studies are necessary to define whether MSI/MMR-d UCSs have better prognosis.

Prognostic significance of CTNNB1 mutation in early stage endometrial carcinoma: a systematic review and meta-analysis

Background

In the last years, mutations in the exon 3 of CTNNB1 have emerged as a possible prognostic factor for recurrence in early stage endometrioid endometrial carcinoma, especially in cases with no specific molecular profile (NSMP).

Objective

To define the prognostic value of CTNNB1 mutations in early stage endometrioid endometrial carcinoma, through a systematic review and meta-analysis.

Methods

Electronic databases were searched from their inception to November 2020 for all studies assessing the prognostic value of CTNNB1 mutation in early stage (FIGO I–II) endometrioid endometrial carcinoma. Odds ratio (OR) for tumor recurrence and hazard ratio (HR) for disease-free survival (DFS) were calculated with a significant p value < 0.05.

Results

Seven studies with 1031 patients were included. Four studies were suitable for meta-analysis of OR and showed significant association between CTNNB1 mutation and the absolute number of recurrence (OR = 3.000; p = 0.019); the association became stronger after excluding patients with known molecular status other than NSMP (HR = 5.953; p = 0.012). Three studies were suitable for meta-analysis of HR and showed no significant association between CTNNB1 mutation and decreased DFS (HR = 1.847; p = 0.303); the association became significant after excluding patients with known molecular status other than NSMP (HR = 2.831; p = 0.026).

Conclusion

CTNNB1 mutation is significantly associated with recurrence in early stage endometrioid endometrial carcinomas, especially in the NSMP, appearing potentially useful in directing adjuvant treatment.

High-grade endometrial carcinomas: Morphologic spectrum and molecular classification

High-grade endometrial carcinoma (HGEC) is a heterogeneous group of tumors with various morphologic, genetic, and clinical characteristics. Morphologically, HGEC includes high-grade endometrioid carcinoma, serous carcinoma, clear cell carcinoma, undifferentiated/dedifferentiated carcinoma, and carcinosarcoma. The morphologic classification has been used for prognostication and treatment decisions. However, patient management based on morphologic classification is limited by suboptimal interobserver reproducibility, variable clinical outcomes observed within the same histotype, and frequent discordant histotyping/grading between biopsy and hysterectomy specimens. Recent studies from The Cancer Genome Atlas (TCGA) Research Network established four distinct molecular subtypes: POLE-ultramutated, microsatellite unstable, copy number high, and copy number low groups. Compared to histotyping, the TCGA molecular classification appears superior in risk stratification. The best prognosis is seen in the POLE-ultramutated group and the worst in copy number high group, while the prognosis in the microsatellite unstable and copy number low groups is in between. The TCGA subtyping is more reproducible and shows a better concordance between endometrial biopsy and resection specimens. It has now become apparent that the molecular classification can supplement histotyping in patient management. This article provides an overview of the pathologic diagnosis/differential diagnosis of HGEC and the TCGA classification of endometrial cancers, with the clinical significance and applications of TCGA classification briefly discussed when appropriate.

Immunohistochemistry in gynecologic carcinomas: Practical update with diagnostic and clinical considerations based on the 2020 WHO classification of tumors

This review provides an update on immunohistochemistry applications-diagnostic, prognostic, and predictive-in the pathology evaluation of gynecologic carcinomas. The 5th edition of the WHO Classification of Female Genital Tumors introduced important changes in the diagnostic classification of lower genital tract, endometrial, and ovarian carcinomas, with major influence on the routine pathology practice. Lower genital tract carcinomas and their precursor lesions are now classified based on their human papillomavirus (HPV)-associated and HPV-independent pathogenesis, reflecting the clinically significant prognostic differences and impacting the therapeutic decision-making. Immunohistochemical markers have an increasing role in the pathology evaluation of endometrial carcinomas: in addition to their traditional use in the differential diagnosis and histologic subtyping, they have also been recently advocated for prognostic classification as surrogates for the TCGA (The Cancer Genome Atlas) molecular groups. New entities - mesonephric-like adenocarcinoma and gastric (gastrointestinal)-type mucinous adenocarcinoma of the endometrium - have also been added and often require immunostains for diagnostic confirmation. Ovarian carcinomas frequently show overlapping morphologic patterns and heterogeneous appearance within the same tumor, necessitating immunohistochemical work-up. Beyond diagnostic applications, there is increasing clinical demand for screening of inherited cancer syndromes, prediction of prognosis and guiding targeted therapy. Practical issues and pitfalls related to mismatch repair protein immunohistochemistry, HER2, and PD-L1 testing are also discussed.

Selection of endometrial carcinomas for p53 immunohistochemistry based on nuclear features

The World Health Organization endorses molecular subclassification of endometrial endometrioid carcinomas (EECs). Our objectives were to test the sensitivity of tumor morphology in capturing p53 abnormal (p53abn) cases and to model the impact of p53abn on changes to ESGO/ESTRO/ESP (European Society of Gynaecological Oncology/European Society for Radiotherapy and Oncology/European Society of Pathology) risk stratification. A total of 292 consecutive endometrial carcinoma resections received at Foothills Medical Centre, Calgary, Canada (2019–2021) were retrieved and assigned to ESGO risk groups with and without p53 status. Three pathologists reviewed the representative H&E‐stained slides, predicted the p53 status, and indicated whether p53 immunohistochemistry (IHC) would be ordered. Population‐based survival for endometrial carcinomas diagnosed during 2008–2016 in Alberta was obtained from the Alberta Cancer Registry. The cohort consisted mostly of grade 1/2 endometrioid carcinomas (EEC1/2; N = 218, 74.6%). One hundred and fifty‐two EEC1/2 (52.1% overall) were stage IA and 147 (50.3%) were low risk by ESGO. The overall prevalence of p53abn and subclonal p53 was 14.5 and 8.3%, respectively. The average sensitivity of predicting p53abn among observers was 83.6%. Observers requested p53 IHC for 39.4% with 98.5% sensitivity to detect p53abn (99.6% negative predictive value). Nuclear features including smudged chromatin, pleomorphism, atypical mitoses, and tumor giant cells accurately predicted p53abn. In 7/292 (2.4%), p53abn upgraded ESGO risk groups (2 to intermediate risk, 5 to high risk). EEC1/2/stage IA patients had an excellent disease‐specific 5‐year survival of 98.5%. Pathologists can select cases for p53 testing with high sensitivity and low risk of false negativity. Molecular characterization of endometrial carcinomas has great potential to refine ESGO risk classification for a small subset but offers little value for approximately half of endometrial carcinomas, namely, EEC1/2/stage IA cases.

Prognostic value of the TCGA molecular classification in uterine carcinosarcoma

Background

The TCGA molecular groups of endometrial carcinoma are “POLE‐mutated” (POLEmut), “microsatellite‐instable/mismatch repair‐deficient” (MSI/MMRd), “TP53‐mutated/p53‐abnormal” (TP53mut/p53abn), and “no specific molecular profile” (NSMP).

Objective

Prognostic assessment of the TCGA groups in uterine carcinosarcoma (UCS).

Search strategy

Systematic review from January 2000 to January 2021.

Selection criteria

Studies assessing the TCGA groups in UCS.

Data collection and analysis

Progression‐free survival (PFS) and overall survival (OS) were assessed by Kaplan–Meier and Cox analyses (reference: TP53mut/p53abn group) and compared with endometrioid and serous carcinomas (original TCGA cohort), with a significant P < 0.050.

Main results

Five studies with 263 UCS were included. Compared with TP53mut/p53abn UCS, MSI/MMRd UCS showed significantly better PFS (P < 0.001) but similar OS (P = 0.788), whereas NSMP UCS showed similar PFS (P = 0.936) and OS (P = 0.240). Compared with their endometrioid/serous counterparts, NSMP and TP53mut/p53abn UCS showed significantly worse PFS (P < 0.001 and P = 0.004) and OS (P < 0.001 and P < 0.001), while MSI/MMRd UCS showed similar PFS (P = 0.595) but significantly worse OS (P < 0.001). The POLEmut group showed neither recurrences nor deaths in both the UCS and the endometrioid/serous carcinoma cohorts.

Conclusion

POLEmut UCS show excellent prognosis, whereas TP53mut/p53abn and NSMP UCS show a prognosis even worse than that of TP53mut/p53abn endometrioid/serous carcinomas. The prognosis of MSI/MMRd UCS remains to be defined.

POLEmut UCS show the same excellent prognosis as POLEmut endometrioid carcinomas, while TP53mut/p53abn and NSMP UCS show a prognosis even worse than TP53mut/p53abn endometrioid/serous carcinomas.

Clear cell endometrial carcinomas with mismatch repair deficiency have a favorable prognosis: A systematic review and meta-analysis

INTRODUCTION

In the ESGO/ESTRO/ESP guidelines for endometrial carcinoma management, the risk category of clear cell carcinoma (CCC) is not well defined. In fact, while p53-abnormal (p53abn) CCC are known to be aggressive, the prognosis of mismatch repair-deficient (MMRd) and p53-wild-type (p53wt) CCCs is less clear.

OBJECTIVE

To assess the prognostic value of the MMRd and p53wt groups in CCC through a systematic review and meta-analysis.

METHODS

Electronic databases were searched from their inception to February 2021. All studies reporting p53 expression, MMR proteins expression and survival outcomes in endometrial CCC (either pure or mixed) were included. Kaplan-Meier and Cox regression survival analyses with hazard ratio (HR) for overall survival (OS) were performed by using the p53abn group as reference; a significant p-value<0.05 was adopted.

RESULTS

Six studies with 136 CCC (114 pure and 22 mixed) were included. Five-year OS was 95.7 ± 4.3% in the MMRd group, 48.4 ± 8.4% months in the p53wt group and 40.6 ± 10.4% in the p53abn group. The hazard of death was significantly lower in the MMRd group than in the p53abn group (HR = 0.062; p = 0.007), while it did not significantly differ between the p53wt and the p53abn group (HR = 0.673; p = 0.222). The POLEmut group could not be analyzed due to the absence of deaths. Similar results were observed in the pure CCC and mixed CCC subgroups.

CONCLUSION

MMRd CCCs seem to have a favorable prognosis and might be lumped together with MMRd endometrioid carcinoma for management purpose. On the other hand, p53wt CCCs appear prognostically more similar to p53abn CCCs.

New Pathological and Clinical Insights in Endometrial Cancer in View of the Updated ESGO/ESTRO/ESP Guidelines

Endometrial carcinoma represents the most common gynecological cancer in Europe and the USA. Histopathological classification based on tumor morphology and tumor grade has played a crucial role in the management of endometrial carcinoma, allowing a prognostic stratification into distinct risk categories, and guiding surgical and adjuvant therapy. In 2013, The Cancer Genome Atlas (TCGA) Research Network reported a large scale molecular analysis of 373 endometrial carcinomas which demonstrated four categories with distinct clinical, pathologic, and molecular features: POLE/ultramutated (7% of cases) microsatellite instability (MSI)/hypermutated (28%), copy-number low/endometrioid (39%), and copy-number high/serous-like (26%). In the present article, we report a detailed histological and molecular review of all endometrial carcinoma histotypes in light of the current ESGO/ESTRO/ESP guidelines. In particular, we focus on the distribution and prognostic value of the TCGA groups in each histotype.

Targeting Wnt Signaling in Endometrial Cancer

Simple Summary

Wnt has diverse regulatory roles at multiple cellular levels and numerous targeting points, and aberrant Wnt signaling has crucial roles in carcinogenesis, metastasis, cancer recurrence, and chemotherapy resistance; based on these facts, Wnt represents an appealing therapeutic target for cancer treatment. Although preclinical data supports a role for the Wnt signaling pathway in uterine carcinogenesis, this area remains understudied. In this review, we identify the functions of several oncogenes of the Wnt/β-catenin signaling pathway in tumorigenesis and address the translation approach with potent Wnt inhibitors that have already been established or are being investigated to target key components of the pathway. Further research is likely to expand the potential for both biomarker and cancer drug development. There is a scarcity of treatment choices for advanced and recurrent endometrial cancer; investigating the sophisticated connections of Wnt signaling networks in endometrial cancer could address the unmet need for new therapeutic targets.

Abstract

This review presents new findings on Wnt signaling in endometrial carcinoma and implications for possible future treatments. The Wnt proteins are essential mediators in cell signaling during vertebrate embryo development. Recent biochemical and genetic studies have provided significant insight into Wnt signaling, in particular in cell cycle regulation, inflammation, and cancer. The role of Wnt signaling is well established in gastrointestinal and breast cancers, but its function in gynecologic cancers, especially in endometrial cancers, has not been well elucidated. Development of a subset of endometrial carcinomas has been attributed to activation of the APC/β-catenin signaling pathway (due to β-catenin mutations) and downregulation of Wnt antagonists by epigenetic silencing. The Wnt pathway also appears to be linked to estrogen and progesterone, and new findings implicate it in mTOR and Hedgehog signaling. Therapeutic interference of Wnt signaling remains a significant challenge. Herein, we discuss the Wnt-activating mechanisms in endometrial cancer and review the current advances and challenges in drug discovery.