Refining prognosis and identifying targetable pathways for high-risk endometrial cancer; a TransPORTEC initiative

Clinical features of ProMisE groups identify different phenotypes of patients with endometrial cancer

BACKGROUND

The Proactive Molecular Risk Classifier for Endometrial Cancer (ProMisE) groups has identified four molecular prognostic groups of endometrial cancer (EC): POLE-mutated (POLE-mt), mismatch repair-deficient (MMR-d), p53-abnormal (p53-abn), p53-wild-type (p53-wt). These groups might have different pathogenesis and risk factors, and might occur in different phenotypes of patients. However, these data are still lacking.

OBJECTIVE

To provide a clinical characterization of the ProMisE groups of EC.

METHODS

A systematic review and meta-analysis was performed by searching seven electronic databases from their inception to December 2020, for all studies reporting clinical characteristics of EC patients in each ProMisE group. Pooled means of age and BMI and pooled prevalence of FIGO stage I and adjuvant treatment in each ProMisE group were calculated.

RESULTS

Six studies with 1, 879 women were included in the systematic review. Pooled means (with standard error) and prevalence values were: in the MMR-d group, age = 66.5 ± 0.6; BMI = 30.6 ± 1.2; stage I = 72.6%; adjuvant treatment = 47.3%; in the POLE-mt group, age = 58.6 ± 2.7; BMI = 27.2 ± 0.9; stage I = 93.7%; adjuvant treatment = 53.6%; in the p53-wt group, age = 64.2 ± 1.9; BMI = 32.3 ± 1.4; stage I = 80.5%; adjuvant treatment = 45.3%; in the p53-abn group, age = 71.1 ± 0.5; BMI = 29.1 ± 0.5; stage I = 50.8%; adjuvant treatment = 64.4%.

CONCLUSION

The ProMisE groups identify different phenotypes of patients. The POLE-mt group included the youngest women, with the lower BMI and the highest prevalence of stage I. The p53-wt group included patients with the highest BMI. The p53-abn group included the oldest women, with the highest prevalence of adjuvant treatment and the lowest prevalence of stage I. The MMR-d group showed intermediate values among the ProMisE groups for all clinical features.

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.

Inhibiting Wnt/beta-catenin in CTNNB1-mutated endometrial cancer

The role of β-catenin/TCF transcriptional activity in endometrial cancer (EC) recurrence is not well understood. We assessed the impact of Wnt/β-catenin inhibition in EC models. In an analysis of the Cancer Genome Atlas, we confirmed that CTNNB1 mutations are enriched in recurrent low-risk EC and showed that aberrant Wnt/β-catenin pathway activation is associated with recurrence. We studied CTNNB1-wildtype (HEC1B, Ishikawa) and CTNNB1-mutant (HEC108, HEC265, HEC1B-S33Y, Ishikawa-S33Y) EC cell lines. Dose response curves were determined for 5 Wnt/β-catenin pathway inhibitors (Wnt-C59, XAV-939, PyrPam, PRI-724, SM04690). XAV939, Wnt-C59 and PyrPam inhibited function upstream of β-catenin transcriptional activity and were ineffective at inhibiting cell viability. In contrast, PRI724 and SM04690 indirectly inhibited β-catenin transcriptional activity and significantly reduced cell viability in CTNNB1-mutant cell lines. Treatment with SM04690 reduced cell viability (Licor Cell stain) in all EC cell lines, but viability was significantly lower in CTNNB1-mutant cell lines (p < 0.01). Mechanistically, SM04690 significantly inhibited proliferation measured via 5'-bromo-2'-deoxyuridine incorporation and reduced T cell factor (TCF) transcriptional activity. HEC1B, HEC1B-S33Y and HEC265 tumor-bearing mice were treated with vehicle or SM04690. Tumors treated with SM04690 had smaller mean volumes than those treated with vehicle (p < 0.001, p = 0.014, p = 0.06). In HEC1B-S33Y and HEC265 tumors, SM04690 treatment significantly reduced Ki67 H-scores compared to vehicle (p = 0.035, p = 0.024). Targeting the Wnt/β-catenin pathway in CTNNB1-mutant EC effectively inhibited proliferation and β-catenin/TCF transcriptional activity and blunted tumor progression in in vivo models. These studies suggest β-catenin transcriptional inhibitors are effective in EC and particularly in CTNNB1-mutant EC, highlighting a potential therapeutic vulnerability for treatment of CTNNB1-mutant EC.

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.

Inactivating Mutations of the IK Gene Weaken Ku80/Ku70-Mediated DNA Repair and Sensitize Endometrial Cancer to Chemotherapy

IK is a mitotic factor that promotes cell cycle progression. Our previous investigation of 271 endometrial cancer (EC) samples from the Cancer Genome Atlas (TCGA) dataset showed IK somatic mutations were enriched in a cluster of patients with high-grade and high-stage cancers, and this group had longer survival. This study provides insight into how IK somatic mutations contribute to EC pathophysiology. We analyzed the somatic mutational landscape of IK gene in 547 EC patients using expanded TCGA dataset. Co-immunoprecipitation and mass spectrometry were used to identify protein interactions. In vitro and in vivo experiments were used to evaluate IK's role in EC. The patients with IK-inactivating mutations had longer survival during 10-year follow-up. Frameshift and stop-gain were common mutations and were associated with decreased IK expression. IK knockdown led to enrichment of G2/M phase cells, inactivation of DNA repair signaling mediated by heterodimerization of Ku80 and Ku70, and sensitization of EC cells to cisplatin treatment. IK/Ku80 mutations were accompanied by higher mutation rates and associated with significantly better overall survival. Inactivating mutations of IK gene and loss of IK protein expression were associated with weakened Ku80/Ku70-mediated DNA repair, increased mutation burden, and better response to chemotherapy in patients with EC.

High-risk endometrial cancer proteomic profiling reveals that FBXW7 mutation alters L1CAM and TGM2 protein levels

BACKGROUND

FBXW7 is frequently somatically mutated in grade 3 endometrioid endometrial cancers (G3EECs) and serous endometrial cancers (SECs), which are high-risk cancers associated with poor outcomes and in need of novel treatment options. The aim of this study was to determine the proteomic effects of 3 FBXW7 mutations in high-risk endometrial cancers (ECs).

METHODS

Clustered regularly interspaced short palindromic repeats (CRISPR) editing was used to generate 3 HEC-50B G3EEC derivative cell lines, each of which harbored 1 FBXW7 mutation, and to revert an endogenous FBXW7 mutation in HEC-1-B grade 2 endometrioid endometrial cancer (G2EEC) cells to the wild-type genotype. Proteomic profiling based on liquid chromatography-tandem mass spectrometry was used to determine protein differences between the HEC-50B derivative lines and parental cells. Western blot analysis was performed to assess differential protein levels of CRISPR-edited derivative lines originating from HEC-50B, ARK1 (SEC), ARK4 (SEC), HEC-1-B, and JHUEM-1 (G2EEC) cell lines in comparison with parental cells.

RESULTS

Results of this study demonstrated the effects of FBXW7 mutations on the proteome and phosphoproteome of HEC-50B G3EEC cells and highlighted proteins that also exhibited altered levels in FBXW7-mutated ARK1 and ARK4 SEC cells, including 2 potentially druggable proteins: L1 cell adhesion molecule (L1CAM) and transglutaminase 2 (TGM2). Furthermore, they demonstrated that reversion of an endogenous FBXW7 mutation to the wild-type genotype in JHUEM-1 and HEC-1-B G2EEC cells resulted in decreased L1CAM and TGM2 protein levels.

CONCLUSIONS

L1CAM and TGM2 protein levels are affected by FBXW7 mutations in ECs.

Mismatch repair deficiency and clinicopathological characteristics in endometrial carcinoma: a systematic review and meta-analysis

Background

Loss of mismatch repair (MMR) occurs frequently in endometrial carcinoma (EC) and is an important prognostic marker. However, the frequency of MMR deficiency (D-MMR) in EC remains inconclusive. This systematic review and meta-analysis addressed this inconsistency and evaluated related clinicopathology.

Methods

Electronic databases were searched for articles: PubMed, Science Direct, Web of Science, EMBASE, and the Wiley Online Library. Data were extracted from 25 EC studies of D-MMR to generate a clinical dataset of 7,459 patients. A random-effects model produced pooled estimates of D-MMR EC frequency with 95% confidence interval (CI) for meta-analysis.

Results

The overall pooled proportion of D-MMR was 24.477% (95% CI, 21.022 to 28.106) in EC. The Lynch syndrome subgroup had 22.907% pooled D-MMR (95% CI, 14.852 to 32.116). D-MMR was highest in type I EC (25.810) (95% CI, 22.503 to 29.261) compared to type II (13.736) (95% CI, 8.392 to 20.144). Pooled D-MMR was highest at EC stage and grades I–II (79.430% and 65.718%, respectively) and lowest in stages III–IV and grade III (20.168% and 21.529%). The pooled odd ratios comparing D-MMR to proficient MMR favored low-stage EC disease (1.565; 0.894 to 2.740), lymphovascular invasion (1.765; 1.293 to 2.409), and myometrial invasion >50% (1.271; 0.871 to 1.853).

Conclusions

Almost one-quarter of EC patients present with D-MMR tumors. The majority has less aggressive endometrioid histology. D-MMR presents at lower tumor stages compared to MMR-proficient cases in EC. However other metastatic parameters are comparatively higher in the D-MMR disease setting.

Immunohistochemical biomarkers are prognostic relevant in addition to the ESMO-ESGO-ESTRO risk classification in endometrial cancer

OBJECTIVE

Pre-operative immunohistochemical (IHC) biomarkers are not incorporated in endometrial cancer (EC) risk classification. We aim to investigate the added prognostic relevance of IHC biomarkers to the ESMO-ESGO-ESTRO risk classification and lymph node (LN) status in EC.

METHODS

Retrospective multicenter study within the European Network for Individualized Treatment of Endometrial Cancer (ENITEC), analyzing pre-operative IHC expression of p53, L1 cell-adhesion molecule (L1CAM), estrogen receptor (ER) and progesterone receptor (PR), and relate to ESMO-ESGO-ESTRO risk groups, LN status and outcome.

RESULTS

A total of 763 EC patients were included with a median follow-up of 5.5-years. Abnormal IHC expression was present for p53 in 112 (14.7%), L1CAM in 79 (10.4%), ER- in 76 (10.0%), and PR- in 138 (18.1%) patients. Abnormal expression of p53/L1CAM/ER/PR was significantly related with higher risk classification groups, and combined associated with the worst outcome within the 'high and advanced/metastatic' risk group. In multivariate analysis p53-abn, ER/PR- and ESMO-ESGO-ESTRO 'high and advanced/metastatic' were independently associated with reduced disease-specific survival (DSS). Patients with abnormal IHC expression and lymph node metastasis (LNM) had the worst outcome. Patients with LNM and normal IHC expression had comparable outcome with patients without LNM and abnormal IHC expression.

CONCLUSION

The use of pre-operative IHC biomarkers has important prognostic relevance in addition to the ESMO-ESGO-ESTRO risk classification and in addition to LN status. For daily clinical practice, p53/L1CAM/ER/PR expression could serve as indicator for surgical staging and refine selective adjuvant treatment by incorporation into the ESMO-ESGO-ESTRO risk classification.

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.

Salvage Radiation for Pelvic Relapse after Surgically Treated Endometrial Cancer

(1) Background: This study evaluated the clinical outcome after salvage radiotherapy for first pelvic relapse after endometrial cancer (EC). (2) Methods: This multicenter retrospective study included EC patients with first central pelvic relapse without lymph node involvement treated with curative intent. Progression-free (PFS) and overall survival (OS) were calculated with the Kaplan-Meier method and possible predictive factors for risk of relapse and mortality were identified using the Cox model. (3) Results: We included 139 patients with median EQD2 (Equivalent Dose in 2 Gy fractions) to the clinical target volume of 70.0 Gy. During follow up of median 6.66 years, 39.6% patients developed a second relapse. Risk group classification at primary diagnosis based on histology, grading and FIGO stage and how the pelvic tumor boost was administered were independently associated with PFS and OS. Five-year OS was 68% (95% CI (59-75)) for the whole cohort. Five-year OS was 88% (95% CI (75-94)), 72% (95% CI (55-84)) and 38% (95% CI (15-60)) for the stage I low-, intermediate- and high-risk group, respectively. (4) Conclusions: The majority of central pelvic recurrences in RT-naive EC women can be successfully salvaged with radiotherapy. However, survival in patients with high-risk disease remains poor and warrants a more individualized approach to optimize outcome.

Tumor-infiltrating lymphocytes and POLE mutation in endometrial carcinoma

BACKGROUND

Polymerase-ε (POLE)-mutated endometrial carcinomas (ECs) have displayed an increased number of tumor-infiltrating lymphocytes (TIL) compared to POLE-wild-type ECs. However, it is unclear if TIL may aid in identifying POLE-mutated ECs when molecular data are unavailable. The identification of a POLE mutation surrogate may be crucial to translate TCGA/ProMisE risk assessment in the clinical practice.

AIM

To assess TIL as histological surrogate of POLE mutation in EC.

MATERIALS AND METHODS

Seven electronic databases were searched from their inception to September 2020 for studies that allowed data extraction about TIL and TCGA/ProMisE groups of EC. We calculated pooled sensitivity, specificity, positive and negative likelihood ratios (LR+ and LR-), diagnostic odds ratio (DOR) and area under the curve (AUC) on SROC curves of TIL in distinguishing POLE-mutated from i) POLE-wild-type, ii) no specific molecular profile (NSMP), iii) POLE-wild-type/MMR-proficient, iii) MMR-deficient ECs.

RESULTS

10 studies assessing 1169 women were included in the qualitative analysis. TIL-high pattern showed: sensitivity = 0.65, specificity = 0.63, LR + =2.06, LR- = 0.48, DOR = 4.39, AUC = 0.7532 for POLE-mutant vs POLE-wild-type ECs; sensitivity = 0.85, specificity = 0.73, LR + =2.80, LR- = 0.22, DOR = 15.17 for POLE-mutant vs NSMP ECs; sensitivity = 0.85, specificity = 0.66, LR + =2.49, LR- = 0.25, DOR = 10.30 for POLE-mutant vs POLE-wild-type/MMR-proficient ECs; sensitivity = 0.68, specificity = 0.44, LR + =1.38, LR- = 0.64, DOR = 2.68, AUC = 0.6694 for POLE-mutant vs MMR-deficient ECs.

CONCLUSION

TIL-high pattern shows a moderate accuracy in distinguishing POLE-mutated from POLE-wild-type ECs after the exclusion of MMR-deficient cases. TIL might be considered in an integrate algorithm to identify POLE-mutated ECs when sequencing is unavailable. Further studies are necessary in this regard.

Molecular subtype diagnosis of endometrial carcinoma: comparison of the next-generation sequencing panel and Proactive Molecular Risk Classifier for Endometrial Cancer classifier

The Cancer Genome Atlas-based molecular classification of endometrial carcinoma (EC) has the potential to better identify those patients whose disease is likely to behave differently than predicted when using traditional risk stratification; however, the optimal approach to molecular subtype assignment in routine practice remains undetermined. The aim of this study was to compare the results of two different widely available approaches to diagnosis the EC molecular subtype. EC specimens from 60 patients were molecularly subclassified using two different methods, by using the FoundationOne CDx next-generation sequencing (NGS) panel and using the Proactive Molecular Risk Classifier for Endometrial Cancer (ProMisE) classifier and performing immunostaining for mismatch repair proteins and p53. POLE mutation status was derived from FoundationOne results in both settings. Molecular classification based on ProMisE was successful for all 60 tumors. Microsatellite instability status could be determined based on the NGS panel results in 53 of 60 tumors, so ProMisE and NGS molecular subtype assignment could be directly compared for these 53 tumors. Molecular subtype diagnosis based on NGS and ProMisE was in agreement for 52 of 53 tumors. One tumor was microsatellite stable but showed loss of MLH1 and PMS2 expression. Molecular subtype diagnosis of EC based on the NGS panel of formalin-fixed paraffin-embedded ECs and based primarily on immunostaining (ProMisE) yields identical results in 98.1% (52/53, kappa = 0.97) of cases. Although results obtained using these two approaches are comparable, each has advantages and disadvantages that will influence the choice of the method to be used in clinical practice.

Tumor Molecular Features Predict Endometrial Cancer Patients' Survival After Open or Minimally Invasive Surgeries

Background

The Cancer Genome Atlas (TCGA) project shed light on the vital role of tumor molecular features in predicting endometrial cancer patients’ prognosis. This study aims to investigate the survival impact of surgical approaches on patients with different genetic alterations.

Methods

473 endometrial cancer patients from TCGA database were selected. To analyze the prognostic impact of surgical approach, survival analyses were conducted in patients with different molecular features. Finally, a simplified molecular stratification model was established to select patients suitable for open or minimally invasive surgery (MIS).

Results

In our cohort, 291 patients received open surgery and 182 received MIS. Molecular features influenced patients’ survival after different surgical approaches. Based on survival analyses, three molecular subtypes were generated, with subtype 1 harboring POLE mutation (POLE^mt), microsatellite-instability high (MSI-H), homologous recombination repair (HRR) pathway mutation or MUC16 mutation (MUC16^mt); subtype 3 carrying TP53 mutation; and subtype 2 without specific molecular feature. The survival influence of molecular subtypes depended on surgical approaches. In the open surgery cohort, three subtypes showed similar survival outcome, while in the MIS cohort, prognosis varied significantly among three subtypes, with subtype 1 the best and subtype 3 the worst. In stepwise Cox regression, molecular subtype was an independent predictor of recurrence-free survival in patients receiving MIS (p < 0.001).

Conclusion

The molecular features of endometrial cancer are associated with patients’ prognosis after different surgical approaches. MIS should be recommended in patients with POLE^mt, MSI-H, HRR pathway mutation or MUC16^mt, while for patients with TP53 mutation, open surgery is better concerning oncological safety.

ARID1A and CTNNB1/β-Catenin Molecular Status Affects the Clinicopathologic Features and Prognosis of Endometrial Carcinoma: Implications for an Improved Surrogate Molecular Classification

The collaborative Cancer Genome Atlas (TCGA) project identified four distinct prognostic groups of endometrial carcinoma (EC) based on molecular alterations: (i) the ultramutated subtype that encompasses POLE mutated (POLE) cases; (ii) the hypermutated subtype, characterized by MisMatch Repair deficiency (MMRd); (iii) the copy-number high subtype, with p53 abnormal/mutated features (p53abn); (iv) the copy-number low subtype, known as No Specific Molecular Profile (NSMP). Although the prognostic value of TCGA molecular classification, NSMP carcinomas present a wide variability in molecular alterations and biological aggressiveness. This study aims to investigate the impact of ARID1A and CTNNB1/β-catenin alterations by targeted Next-generation sequencing (NGS) and immunohistochemistry (IHC) in a consecutive series of 125 molecularly classified ECs. NGS and IHC were used to assign surrogate TCGA groups and to identify molecular alterations of multiple target genes including POLE, PTEN, ARID1A, CTNNB1, TP53. Associations with clinicopathologic parameters, molecular subtypes, and outcomes identified NSMP category as the most heterogeneous group in terms of clinicopathologic features and outcome. Integration of surrogate TCGA molecular classification with ARID1A and β-catenin analysis showed NSMP cases with ARID1A mutation characterized by the worst outcome with early recurrence, while NSMP tumors with ARID1A wild-type and β-catenin alteration had indolent clinicopathologic features and no recurrence. This study indicates how the identification of ARID1A and β-catenin alterations in EC represents a simple and effective way to characterize NSMP tumor aggressiveness and metastatic potential.

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.

Histone Modifying Enzymes in Gynaecological Cancers

Simple Summary

Epigenetics is a process that allows genetic control, without the involvement of sequence changes to DNA or genes. In cancer, epigenetics is a key event in tumour development that can alter the expression of cancer driver genes and result in genomic instability. Due to the critical role of epigenetics in malignant transformation, therapies that target these processes have been developed to treat cancer. Here, we provide a summary of the epigenetic changes that have been described in a variety of gynaecological cancers. We then highlight how these changes are being targeted in preclinical models and clinical trials for gynaecological cancers.

Abstract

Genetic and epigenetic factors contribute to the development of cancer. Epigenetic dysregulation is common in gynaecological cancers and includes altered methylation at CpG islands in gene promoter regions, global demethylation that leads to genome instability and histone modifications. Histones are a major determinant of chromosomal conformation and stability, and unlike DNA methylation, which is generally associated with gene silencing, are amenable to post-translational modifications that induce facultative chromatin regions, or condensed transcriptionally silent regions that decondense resulting in global alteration of gene expression. In comparison, other components, crucial to the manipulation of chromatin dynamics, such as histone modifying enzymes, are not as well-studied. Inhibitors targeting DNA modifying enzymes, particularly histone modifying enzymes represent a potential cancer treatment. Due to the ability of epigenetic therapies to target multiple pathways simultaneously, tumours with complex mutational landscapes affected by multiple driver mutations may be most amenable to this type of inhibitor. Interrogation of the actionable landscape of different gynaecological cancer types has revealed that some patients have biomarkers which indicate potential sensitivity to epigenetic inhibitors. In this review we describe the role of epigenetics in gynaecological cancers and highlight how it may exploited for treatment.

p53abn Endometrial Cancer: understanding the most aggressive endometrial cancers in the era of molecular classification

Over the past decade, our understanding of endometrial cancer has changed dramatically from the two-tiered clinicopathologic classification system of type I and type II endometrial cancer through to the four distinct molecular subtypes identified by The Cancer Genome Atlas (TCGA) in 2013. In both systems there is a small subset of endometrial cancers (serous histotype/high numbers of somatic copy number abnormalities) that account for a disproportionately high percentage of endometrial cancer related deaths. This subset can be identified in routine clinical practice by first identifying the approximately one-third of endometrial cancers that are either ultramutated/POLEmut tumors, with pathogenic mutations in the exonuclease domain of POLE, or hypermutated/MMRd tumors, with loss of DNA mismatch repair. Immunostaining for p53 stratifies the remaining endometrial cancers into those with wild-type staining pattern and those with mutant pattern staining (p53abn endometrial cancer). This latter group of p53abn endometrial cancer is the subject of this review. Most p53abn endometrial cancers are serous type and high grade, but it also includes other histotypes and lower grade tumors, and has consistently been associated with the poorest clinical outcomes. Although it only accounts for 15% of all endometrial cancer cases, it is responsible for 50-70% of endometrial cancer mortality. A better understanding of the molecular alterations in the p53abn subgroup, beyond the ubiquitous and definitional TP53 mutations, is required so we can identify better treatments for these most aggressive endometrial cancers. Recent evidence has shown improved survival outcomes with the addition of chemotherapy compared with radiation alone in p53abn endometrial cancers. Opportunities for targeted therapy for p53abn endometrial cancers also exist with a proportion of p53abn endometrial cancers known to have homologous recombination deficiency (HRD) or human epidermal growth factor 2 (HER2) overexpression/amplification. This review will provide an overview of our current understanding of p53abn endometrial cancer.

Endometrial carcinoma: molecular subtypes, precursors and the role of pathology in early diagnosis

Endometrial carcinoma (EC) is classified into a wide range of morphological variants; this list has expanded over the past decade with the inclusion of mesonephric-like and dedifferentiated carcinoma as EC variants in the fifth edition of the WHO Classification of Female Genital Tumours, and recognition that carcinosarcoma is a biphasic carcinoma rather than a sarcoma. Each EC variant has distinct molecular abnormalities, including TCGA-based molecular subtypes, allowing further subclassification and adding complexity. In contrast to this rapid progress in understanding EC, there are only two recognized EC precursor lesions: endometrial atypical hyperplasia/endometrioid intraepithelial neoplasia (EAH/EIN) and serous intraepithelial carcinoma, a situation that has not changed for many years. Diagnosis of EC precursors is a cornerstone of surgical pathology practice, with early diagnosis contributing to the relatively favorable prognosis of EC. In this review we relate the precursor lesions to each of the EC morphological variants and molecular subtypes, discuss how successful early diagnosis is for each variant/molecular subtype and how it might be improved, and identify knowledge gaps where there is insufficient understanding of EC histogenesis. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

The Perspectives of Fertility Preservation in Women with Endometrial Cancer

Simple Summary

Endometrial cancer is a common gynecological malignant disease. Its incidence in women of reproductive age in developed countries is increasing. The standard treatment is surgical in the form of hysterectomy and bilateral salpingo-oophorectomy, which has a significant impact on the quality of women’s lives and precludes further fertility. Conservative management to preserve reproductive function and delay final surgery can today be considered in carefully selected women. We analyze the current approaches to select appropriate candidates and current medical regimens for fertility sparing management. We elaborate on the future perspectives of management. With better characterization of the disease and implementation of molecular biomarkers, more women should be able to benefit from conservative approaches to management of endometrial cancer.

Abstract

Endometrial cancer is the most common gynecological cancer in developed countries. The disease is diagnosed with increasing frequency in younger women, commonly also in their reproductive age. The standard treatment of endometrial cancer is surgical in the form of hysterectomy and bilateral salpingo-oophorectomy, and this precludes future fertility in younger women. The current challenge is to identify the group of women with endometrial cancer and low-risk features that would benefit from more conservative treatment options. More focus in management needs to be aimed towards the preservation of quality of life, without jeopardizing oncological outcomes. In this review, we analyze the current approaches to identification of women for conservative management and evaluate the success of different medical options for treatment and surgical techniques that are fertility sparing. We also elaborate on the future perspectives, focusing on the incorporation of molecular characterization of endometrial cancer to fertility preservation algorithms. Future studies should focus specifically on identifying reliable clinical and molecular predictive markers in this group of young women. With improved knowledge and better risk assessment, the precision medicine is the path towards improved understanding of the disease and possibly widening the group of women that could benefit from treatment methods preserving their fertility.

Circulating tumor DNA as a prognostic marker in high-risk endometrial cancer

BACKGROUND

Currently, there is no reliable blood-based marker to track tumor recurrence in endometrial cancer (EC) patients. Liquid biopsies, specifically, circulating tumor DNA (ctDNA) analysis emerged as a way to monitor tumor metastasis. The objective of this study was to examine the feasibility of ctDNA in recurrence surveillance and prognostic evaluation of high-risk EC.

METHODS

Tumor tissues from nine high-risk EC patients were collected during primary surgery and tumor DNA was subjected to next generation sequencing to obtain the initial mutation spectrum using a 78 cancer-associated gene panel. Baseline and serial post-operative plasma samples were collected and droplet digital PCR (ddPCR) assays for patient-specific mutations were developed to track the mutations in the ctDNA in serial plasma samples. Log-rank test was used to assess the association between detection of ctDNA before or after surgery and disease-free survival.

RESULTS

Somatic mutations were identified in all of the cases. The most frequent mutated genes were PTEN, FAT4, ARID1A, TP53, ZFHX3, ATM, and FBXW7. For each patient, personalized ddPCR assays were designed for one-to-three high-frequent mutations. DdPCR analysis and tumor panel sequencing had a high level of agreement in the assessment of the mutant allele fractions in baseline tumor tissue DNA. CtDNA was detected in 67% (6 of 9) of baseline plasma samples, which was not predictive of disease-free survival (DFS). CtDNA was detected in serial post-operative plasma samples (ctDNA tracking) of 44% (4 of 9) of the patients, which predicted tumor relapse. The DFS was a median of 9 months (ctDNA detected) versus median DFS undefined (ctDNA not detected), with a hazard ratio of 17.43 (95% CI, 1.616-188.3). The sensitivity of post-operative ctDNA detection in estimating tumor relapse was 100% and specificity was 83.3%, which was superior to CA125 or HE4.

CONCLUSIONS

Personalized ctDNA detection was effective and stable for high-risk EC. CtDNA tracking in post-operative plasma is valuable for predicting tumor recurrence.

Homologous Recombination Repair Mechanisms in Serous Endometrial Cancer

Simple Summary

Serous endometrial cancer is an unusual and aggressive endometrial cancer subtype, conferring the highest mortality of all endometrial cancers. In many ways, it resembles the more common tumor entity high-grade serous ovarian cancer. Thus, there is an urgent need for better treatment options for serous endometrial cancer patients. It is crucial for all dividing cells that the DNA repair is functioning correctly. Our aim was to investigate deficiencies in DNA repair in serous endometrial cancer, in particular the presence of homologous recombination repair deficiency. This kind of DNA repair defect may indicate that a specific targeted therapy, so-called PARP inhibitors, which are already in use for the treatment of ovarian cancer, may be useful also in serous endometrial cancer. This study contributes to the largely unexplored field of DNA repair deficiencies in serous endometrial cancer, and may hence contribute to future improved prognosis for these patients.

Abstract

Serous endometrial cancer (SEC) resembles high-grade serous ovarian cancer (HGSOC) genetically and clinically, with recurrent copy number alterations, TP53 mutations and a poor prognosis. Thus, SEC patients may benefit from targeted treatments used in HGSOC, e.g., PARP inhibitors. However, the preclinical and clinical knowledge about SEC is scarce, and the exact role of defective DNA repair in this tumor subgroup is largely unknown. We aimed to outline the prevalence of homologous recombination repair deficiency (HRD), copy-number alterations, and somatic mutations in SEC. OncoScan SNP arrays were applied to 19 tumors in a consecutive SEC series to calculate HRD scores and explore global copy-number profiles and genomic aberrations. Copy-number signatures were established and targeted sequencing of 27 HRD-associated genes was performed. All factors were examined in relation to HRD scores to investigate potential drivers of the HRD phenotype. Ten of the 19 SEC tumors (53%) had an HRD score > 42, considered to reflect an HRD phenotype. Higher HRD score was associated with loss of heterozygosity in key HRD genes, and copy-number signatures associated with non-BRCA1/2 dependent HRD in HGSOC. A high number of SECs display an HRD phenotype. It remains to be elucidated whether this also confers PARP inhibitor sensitivity.

Distinctive genomic characteristics in POLE/POLD1-mutant cancers can potentially predict beneficial clinical outcomes in patients who receive immune checkpoint inhibitor

Background

Mutations in POLE /POLD1 proofreading domain can cause deficiencies in DNA repair, conferring ultramutated cancer phenotypes. Preliminary clinical studies have revealed an association between POLE/POLD1 mutations and beneficial clinical outcomes to immune checkpoint inhibitor (ICI) therapy This study aims to investigate the genomic characteristics of POLE/POLD-mutant tumors and the prognostic value of POLE/POLD mutation for ICI treatment.

Methods

Genomic data of 21,074 patients with 23 cancer types were retrieved from Burning Rock variant database (BR VarDB). The prevalence and spectra of POLE and POLD1 mutations were assessed and compared with that in The Cancer Genome Atlas (TCGA) samples. The correlations of POLE/POLD1 mutation with tumor mutational burden (TMB) and microsatellite instability (MSI) were investigated. The prognostic value of POLE/POLD1 mutations was also explored in 2,487 ICI-treated patients from published studies.

Results

BR VarDB samples displayed a similar mutational prevalence of POLE (3.2% vs. 3.2%) and POLD1 (1.4% vs. 1.6%, P=0.248) versusTCGA samples, but a slightly lower frequency of POLE and POLD1 co-mutations (0.21% vs. 0.43%, P<0.001). POLE/POLD1-mutant tumors harbored increased TCT→TAT and TCG→TTG transversions, and genomic signatures associated with DNA mismatch repair (MMR) deficiency and ultra-hypermuation. Furthermore, tumors with POLE/POLD1 proofreading mutation showed a significantly higher TMB than tumors with non-proofreading mutations (P<0.01), although both possessed a higher TMB than POLE/POLD1 wild-type (WT) tumors (P<0.0001 and P<0.0001, respectively). MSI was commonly observed in tumors harboring dominant clone of POLE/POLD1 mutation (10.2%), but occurred rarely in POLE/POLD1 WT tumors (0.5%) and tumors with accumulating sub-cloned POLE/POLD1 mutation (0%). Survival analysis revealed that POLE/POLD1 mutation was not independently correlated with longer survival after adjusting for TMB and other factors (HR =0.86, P=0.372). However, patients harboring POLE/POLD1 mutation demonstrated a higher response rate than patients with POLE/ POLD1 WT tumors (35.2% vs. 19.6%, P=0.0165).

Conclusions

We delineated distinctive genomic characteristics in POLE/POLD1-mutant tumors, suggesting the potential predictive role of POLE/POLD1 mutations, especially those in the proofreading domain, for beneficial outcomes of immunotherapy. Our results also suggest that MSI caused by a loss-of-function mutation in the MMR pathway tends to result from POLE/POLD1 proofreading deficiency in POLE/POLD1-mutant tumors with MSI.

Endometrial cancer: a genetic point of view

BACKGROUND

Endometrial cancer is the fourth most frequent gynecological cancer and the most frequent type of uterine cancer. There is an increase in the incidence and mortality of uterine cancers in the past few decades, and there are no well-established screening programs for endometrial cancer currently. Most endometrial cancers arise through the interplay of familial, genetic, and lifestyle factors. Although a number of genetic factors modify endometrial cancer susceptibility, they are not of standard use in the clinical assessment of prognosis. We conducted a comprehensive systematic literature review to provide an overview of the relationship between genetic factors and risk for endometrial cancer.

METHODS

MEDLINE and EMBASE databases were searched for studies between January 2010 to March 2020 reporting the genes associated with endometrial cancer.

RESULTS

Through the selection process, we retrieved 186 studies comprising 329 genes identified using several molecular methodologies in all human chromosomes and in mitochondrial DNA. Endometrial cancer exhibits a molecular complexity and heterogeneity coherent with its clinical and histologic variability. Improved characterization of molecular alterations of each histological type provides relevant information about the prognosis and potential response to new therapies.

CONCLUSIONS

The current challenge is the integration of clinicopathologic and molecular factors to improve the diagnosis, prognosis, and treatment of endometrial cancer.

Prognostic Integrated Image-Based Immune and Molecular Profiling in Early-Stage Endometrial Cancer

Optimum risk stratification in early-stage endometrial cancer combines clinicopathologic factors and the molecular endometrial cancer classification defined by The Cancer Genome Atlas (TCGA). It is unclear whether analysis of intratumoral immune infiltrate improves this. We developed a machine-learning, image-based algorithm to quantify density of CD8+ and CD103+ immune cells in tumor epithelium and stroma in 695 stage I endometrioid endometrial cancers from the PORTEC-1 and -2 trials. The relationship between immune cell density and clinicopathologic/molecular factors was analyzed by hierarchical clustering and multiple regression. The prognostic value of immune infiltrate by cell type and location was analyzed by univariable and multivariable Cox regression, incorporating the molecular endometrial cancer classification. Tumor-infiltrating immune cell density varied substantially between cases, and more modestly by immune cell type and location. Clustering revealed three groups with high, intermediate, and low densities, with highly significant variation in the proportion of molecular endometrial cancer subgroups between them. Univariable analysis revealed intraepithelial CD8+ cell density as the strongest predictor of endometrial cancer recurrence; multivariable analysis confirmed this was independent of pathologic factors and molecular subgroup. Exploratory analysis suggested this association was not uniform across molecular subgroups, but greatest in tumors with mutant p53 and absent in DNA mismatch repair-deficient cancers. Thus, this work identified that quantification of intraepithelial CD8+ cells improved upon the prognostic utility of the molecular endometrial cancer classification in early-stage endometrial cancer.

Clinico-pathological features associated with mismatch repair deficiency in endometrial undifferentiated/dedifferentiated carcinoma: A systematic review and meta-analysis

BACKGROUND

Endometrial undifferentiated/dedifferentiated carcinoma (UDC/DDC) is a recently described aggressive variant of endometrial carcinoma, which shows mismatch repair (MMR) deficiency in about half of cases.

AIM

To assess whether MMR-deficient UDC/DDC have distinct clinico-pathological features.

MATERIALS AND METHODS

A systematic review and meta-analysis was performed by searching 4 electronic databases from their inception to October 2020 for all studies reporting clinicopathological characteristics of UDC/DDC series. Student t-test (for continuous variables), Cox regression analysis (for overall survival) and odds ratio (OR, for dichotomous variables) were used with a significant p-value < 0.05; data were pooled by using a random effect model.

RESULTS

Twelve studies were included. MMR-deficiency was significantly associated with older age (p = 0.024), p53-wild-type (p = 0.005), ARID1A loss (p = 0.001) and PD-L1 expression (p = 0.019), but not with overall survival (p = 0.307), extension beyond corpus (p = 0.787) or beyond uterus (p = 0.403), presence of a differentiated component (p = 0.461), loss of expression of cytokeratins (p = 0.698), EMA (p = 0.309), estrogen receptor (p = 0.605), PAX8 (p = 0.959), SMARCA4/BRG1 (p = 0.321), SMARCB1/INI1 (p = 0.225) or claudin-4 (p = 0.094), or POLE exonuclease domain mutation p = (0.773).

CONCLUSIONS

In UDC/DDC, MMR-deficiency appears associated with older age, p53-wild type and ARID1A loss, suggesting the possibility of a distinct pathway underlying dedifferentiation; the association with PD-L1 expression is attributable to the high mutational load and may have therapeutic implications. On the other hand, MMR-deficiency appears not to be associated with prognosis, stage, loss of differentiation markers or POLE mutation.

Urinary Biomarkers and Their Potential for the Non-Invasive Detection of Endometrial Cancer

Endometrial cancer is the most common malignancy of the female genital tract and its incidence is rising in parallel with the mounting prevalence of obesity. Early diagnosis has great potential to improve outcomes as treatment can be curative, especially for early stage disease. Current tests and procedures for diagnosis are limited by insufficient accuracy in some and unacceptable levels of invasiveness and discomfort in others. There has, therefore, been a growing interest in the search for sensitive and specific biomarkers for endometrial cancer detection based on non-invasive sampling methodologies. Urine, the prototype non-invasive sample, is attractive for biomarker discovery as it is easily accessible and can be collected repeatedly and in quantity. Identification of urinary biomarkers for endometrial cancer detection relies on the excretion of systemic biomarkers by the kidneys or urinary contamination by biomarkers shed from the uterus. In this review, we present the current standing of the search for endometrial cancer urinary biomarkers based on cytology, genomic, transcriptomic, proteomic, and metabolomic platforms. We summarize the biomarker candidates and highlight the challenges inherent in urinary biomarker discovery. We review the various technologies with promise for biomarker detection and assess these novel approaches for endometrial cancer biomarker research.

Clinicopathologic and Immunohistochemical Correlates of CTNNB1 Mutated Endometrial Endometrioid Carcinoma

Endometrial endometrioid carcinomas (EECs) with exon 3 CTNNB1 mutations characterize a more aggressive subset of tumors in patients with low-grade low-stage disease. Thus, prospectively identifying these cases may be clinically relevant. The aim of this study was to examine the feasibility of β-catenin and Cyclin D1 immunohistochemistry to identify EECs harboring CTNNB1 mutations and to evaluate the clinicopathologic features of EECs with exon 3 CTNNB1 mutations. Thirty-nine CTNNB1 mutated EECs and 40 CTNNB1 wild-type EECs were identified from a cohort of previously sequenced endometrial carcinomas using a targeted next-generation sequencing panel. Immunohistochemistry for β-catenin and Cyclin D1 was performed on all cases. Immunohistochemistry results were correlated with CTNNB1 mutation status and clinicopathologic parameters. Patients with CTNNB1 mutated EECs were younger than those with CTNNB1 wild-type (56.2 vs. 61.5 y; P=0.033). Nuclear β-catenin expression correlated with exon 3 CTNNB1 mutation (P<0.0001) with a sensitivity of 91% and a specificity of 89%. Cyclin D1 expression correlated with CTNNB1 exon 3 mutation with relatively high specificity (90%) but low sensitivity (29%). Recurrence rate in patients with stage IA disease at diagnosis was significantly higher in patients whose tumors were CTNNB1 mutated compared with CTNNB1 wild-type (30% vs. 0%; P=0.025) and included distant metastases; all recurrent tumors in this group harbored exon 3 mutations and were histologically low grade (5 grade 1, 2 grade 2). Nuclear β-catenin expression appears to be an acceptable proxy for CTNNB1 mutation.

DNA Mismatch Repair-deficient Endometrial Carcinosarcomas Portend Distinct Clinical, Morphologic, and Molecular Features Compared With Traditional Carcinosarcomas

Uterine carcinosarcomas (UCSs) are aggressive neoplasms composed of high-grade malignant epithelial and mesenchymal elements with most (∼90%) showing TP53 abnormalities. A subset, however, shows mismatch repair deficiency (MMR-D). We sought to describe their clinical, morphologic, and molecular features. Clinicopathologic data of MMR-D UCSs were recorded including age, stage, follow-up, mismatch repair and p53 immunohistochemistry (IHC), MLH1 promoter methylation status, and germline alterations, TP53 mutation status, microsatellite instability and mutational burden by massively parallel sequencing. Seventeen (6.2%) MMR-D were identified among 276 UCSs. Of MMR-D UCSs, the median age was 60 years. mismatch repair IHC loss is as follows: MLH1/PMS2 65%, MSH2/MSH6 18%, MSH6 12%, and PMS2 6%. MLH1 promoter methylation and Lynch syndrome was identified in 47% and 12% of cases, respectively. Cases with p53 IHC showed the following patterns: wild-type 70%, aberrant 20%, and equivocal 10%. Of cases with sequencing, 88% were hypermutated and microsatellite instability high. High-grade endometrioid, undifferentiated, and clear cell carcinoma was present in 53%, 41%, and 6% of cases, respectively and 47% also showed a low-grade endometrioid component. Most patients presented at an early stage (67%) and upon follow-up, 18% died of disease, 65% showed no evidence of disease, while 18% are alive with disease. Patients with MMR-D UCS are younger than the reported median age (70 y) for traditional UCS and most do not show p53 abnormalities. Low-grade endometrioid and undifferentiated carcinoma were seen in approximately half of all cases. Although UCSs have a high tendency for early extrauterine spread, most patients in our cohort presented at an early stage and at follow-up were no evidence of disease. MMR-D UCSs display distinct clinical, morphologic, and molecular features compared with traditional UCSs.

Histomolecular features of high-grade endometrial cancers

High-grade endometrial cancers (ECs) are an aggressive subset of ECs accounting for 70-80% of EC-related deaths. Currently, staging surgery, together with chemotherapy or radiotherapy, is the primary treatment strategy for these cancers. The widespread use of next-generation sequencing has led to a refined understanding of EC's genomics with important information for diagnosis and therapy for individual patients (precision medicine). However, advances in the genomics assessment of high-grade tumors have been slower due to their lower incidence than low-grade EC. This article will briefly introduce the current state of knowledge of the genomics of G3 endometrioid EC, serous uterine cancer, clear cell uterine carcinoma and uterine carcinosarcoma and discuss its implications for diagnosis and targeted therapy.

Integrating pathology, chromosomal instability and mutations for risk stratification in early-stage endometrioid endometrial carcinoma

Background

Risk stratifications for endometrial carcinoma (EC) depend on histopathology and molecular pathology. Histopathological risk stratification lacks reproducibility, neglects heterogeneity and contributes little to surgical procedures. Existing molecular stratification is useless in patients with specific pathological or molecular characteristics and cannot guide postoperative adjuvant radiotherapies. Chromosomal instability (CIN), the numerical and structural alterations of chromosomes resulting from ongoing errors of chromosome segregation, is an intrinsic biological mechanism for the evolution of different prognostic factors of histopathology and molecular pathology and may be applicable to the risk stratification of EC.

Results

By analyzing CIN25 and CIN70, two reliable gene expression signatures for CIN, we found that EC with unfavorable prognostic factors of histopathology or molecular pathology had serious CIN. However, the POLE mutant, as a favorable prognostic factor, had elevated CIN signatures, and the CTNNB1 mutant, as an unfavorable prognostic factor, had decreased CIN signatures. Only if these two mutations were excluded were CIN signatures strongly prognostic for outcomes in different adjuvant radiotherapy subgroups. Integrating pathology, CIN signatures and POLE/CTNNB1 mutation stratified stageIendometrioid EC into four groups with improved risk prognostication and treatment recommendations.

Conclusions

We revealed the possibility of integrating histopathology and molecular pathology by CIN for risk stratification in early-stage EC. Our integrated risk model deserves further improvement and validation.

Uterine clear cell carcinoma risk in White versus non-White US subpopulations: does race matter?

OBJECTIVE

To determine incidence rates of uterine clear cell carcinoma among non-White US subpopulations.

METHODS

Data from the United States Cancer Statistics and National Cancer Database from 2004 to 2016 were analyzed using descriptive statistics.

RESULTS

A total of 488,811 women were diagnosed with uterine cancer from 2004-2016. Of these, 73.3% were endometrioid, 6.6% were serous, 5.3% were carcinosarcoma, 1.4% were clear cell, and 13.4% were other. Blacks had the highest incidence rate of uterine clear cell compared with Whites, Asian/Pacific Islanders, and American Indian/Alaska Natives (0.59 vs. 0.31, 0.29, and 0.24, respectively). Overall mean age at diagnosis was 68.6 years, with the youngest age in Asian/Pacific Islanders compared to Whites, Blacks, and American Indian/Alaska Natives (65.9 vs. 68.7, 68.6, and 66.3 years, respectively). Analysis of the Asian subpopulation revealed significantly younger age at diagnosis in Vietnamese women (55.8 years) compared with 72.4 years in Japanese, 68.6 years in Pacific Islander, 66.6 years in Indian/Pakistani, 65.9 years in Filipino, 65.8 years in Chinese, 65.2 years in Korean, and 63.7 years in other Asians.

CONCLUSIONS

Black women are two times more likely to be diagnosed with uterine clear cell carcinoma compared with other races. Asians present at younger ages, with Vietnamese women most likely to be diagnosed at the youngest age.

Molecular Profiles of Mixed Endometrial Carcinoma

Mixed endometrial carcinomas are defined as a combination of 2 or more distinct histologic subtypes, one of which must be a type II tumor comprising at least 5% of the tumor volume. The oncogenesis of these tumors remains unclear, particularly in light of the increasingly appreciated morphologic overlap among subtypes, as well as evolving molecular data. We evaluated 8 cases of mixed endometrial carcinoma, including 4 endometrioid (EC)/serous (SC), 1 SC/clear cell (CC), and 3 EC/CC cases, to study the underlying molecular features and oncogenic mechanisms at play. Each component was analyzed by a targeted next-generation sequencing assay. All tumors shared mutations in both components. In 6 cases, one component showed additional mutations. Two EC/SC cases showed shared mutations and mutations unique to each component. When present, unique mutations were typically seen in the SC component, including variants in POLE and TP53, as well as potentially targetable genes DDR2, MAP2K1, and CCNE1. In EC/SC tumors, ERBB2 abnormalities were seen in 2 cases. EC/CC cases showed FGFR2 activating mutations in the EC component only. No fusion drivers were identified. Our data suggest that the majority of these tumors begin as a single clone and diverge along 2 pathways: (1) tumor progression, with one component showing additional mutations, and (2) tumor divergence, in which tumor components have both shared mutations and mutations unique to each component. In addition, the findings suggest a component of morphologic mimicry in these tumors. Our findings are clinically relevant since targetable mutations may be present in only one component of mixed tumors.

Molecular Oncology of Gynecologic Tumors

Oncologists and pathologists alike have recognized that the broad histologic categories, especially for ovarian and endometrial carcinomas, do not reliably segregate groups with similar clinical courses or responses to therapeutic interventions. During the last decade a paradigm shift was invoked when the results from The Cancer Genome Atlas (TCGA) project were published. Comprehensive genomic profiling data from TCGA has shown that there are four molecular subgroups of endometrioid carcinomas instead of the two subtypes proposed by Bokhman in the 1970s. For ovarian carcinomas (OC) it is now evident that molecular parameters are also significant. Although traditionally referred to as a single entity, OC is not a homogeneous disease but rather a group of diseases, each with different morphology and biologic behavior. Similar to endometrial cancers, advanced cervical cancer and recurrent disease remain particularly problematic due to chemotherapy resistance. Effective prophylactic vaccines against the most important carcinogenic human papillomaviruses (HPV) types are available, but uptake remains poor. The E6 and E7 oncoproteins are attractive targets for cancer therapy. They are constitutively expressed in HPV-positive tumors, specific to the tumor, functionally important to the tumor cells and recognized by the adaptive immune system as tumor antigens. This review summarizes recent advances in the molecular pathology, which have greatly improved our understanding of the biology of gynecologic cancers.

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.

The frequency of POLE-mutation in endometrial carcinoma and prognostic implications: a systemic review and meta-analysis

Background

Endometrial carcinoma (EC) is classified into four distinct molecular subgroups including ultramutated DNA polymerase epsilon (POLE). POLE-mutated tumors have the best prognosis and are a promising target for immunotherapy. This meta-analysis consolidated the reported variation of POLE-mutant frequency and assessed prognostic value in EC.

Methods

Internet searches explored scientific data bases: EMBASE, PubMed, and the Cochrane Central Register of Controlled Trials databases. Data was extracted from eligible studies including: sample size, number of positive POLE-mutant cases, sequencing information, clinicopathologic data, and survival data. Meta-analysis and a random-effects model produced pooled estimates of POLE frequency and prognostic parameters using 95% confidence intervals (CI), hazard ratios (HR), and odd ratios (OR).

Results

Six thousand three hundred and forty-six EC patient cases were pooled from 25 studies. The pooled proportion of POLE gene mutation in EC was 8.59% (95% CI, 7.01 to 10.32), of which 8.22% (95% CI, 6.27 to 10.42) were type I and 0.93% (95% CI, 0.34 to 1.81) type 2. Clinicopathologic data showed that POLE-mutated tumors are mostly endometrioid. They present at higher levels in earlier stages (I–II) of EC (89.51%; 95% CI, 81.11 to 95.66) at the highest grade III (51.53%; 95% CI, 36.08 to 66.84) with reduced myometrial invasion (OR, 1.48, 95% CI, 0.99 to 2.20). Survival analysis indicated favorable overall survival (HR, 0.90), disease-specific survival (HR, 0.41), and progression-free survival (HR, 0.23) for POLE mutant EC.

Conclusions

Almost one-tenth of EC patients have POLE-mutated tumors. Given their improved prognostic potential, identifying the POLE mutation status is key for the management of EC patients.

The proportion of endometrial tumours associated with Lynch syndrome (PETALS): A prospective cross-sectional study

BACKGROUND

Lynch syndrome (LS) predisposes to endometrial cancer (EC), colorectal cancer, and other cancers through inherited pathogenic variants affecting mismatch-repair (MMR) genes. Diagnosing LS in women with EC can reduce subsequent cancer mortality through colonoscopic surveillance and aspirin chemoprevention; it also enables cascade testing of relatives. A growing consensus supports LS screening in EC; however, the expected proportion of test positives, and optimal testing strategy is uncertain. Previous studies from insurance-based healthcare systems were limited by narrow selection criteria, failure to apply reference standard tests consistently, and poor conversion to definitive testing. The aim of this study was to establish the prevalence of LS and the diagnostic accuracy of LS testing strategies in an unselected EC population.

METHODS AND FINDINGS

This was a prospective cross-sectional study carried out at a large United Kingdom gynaecological cancer centre between October 2015 and January 2017. Women diagnosed with EC or atypical hyperplasia (AH) were offered LS testing. Tumours underwent MMR immunohistochemistry (IHC), microsatellite instability (MSI), and targeted MLH1-methylation testing. Women <50 years, with strong family histories and/or indicative tumour molecular features, underwent MMR germline sequencing. Somatic MMR sequencing was performed when indicative molecular features were unexplained by LS or MLH1-hypermethylation. The main outcome measures were the prevalence of LS in an unselected EC population and the diagnostic accuracy of clinical and tumour testing strategies for risk stratifying women with EC for MMR germline sequencing. In total, 500 women participated in the study; only 2 (<1%) declined. Germline sequencing was indicated and conducted for 136 and 135 women, respectively. A total of 16/500 women (3.2%, 95% CI 1.8% to 5.1%) had LS, and 11 more (2.2%) had MMR variants of uncertain significance. Restricting testing to age <50 years, indicative family history (revised Bethesda guidelines or Amsterdam II criteria) or endometrioid histology alone would have missed 9/16 (56%), 8/13 (62%) or 9/13 (69%), and 5/16 (31%) cases of LS, respectively. In total 132/500 tumours were MMR deficient by IHC of which 83/132 (63%) had MLH1-hypermethylation, and 16/49 (33%) of the remaining patients had LS (16/132 with MMR deficiency, 12%). MMR-IHC with targeted MLH1-methylation testing was more discriminatory for LS than MSI with targeted methylation testing, with 100% versus 56.3% (16/16 versus 9/16) sensitivity (p = 0.016) and equal 97.5% (468/484) specificity; 64% MSI-H and 73% MMR deficient tumours unexplained by LS or MLH1-hypermethylation had somatic MMR mutations. The main limitation of the study was failure to conduct MMR germline sequencing for the whole study population, which means that the sensitivity and specificity of tumour triage strategies for LS detection may be overestimated, although the risk of LS in women with no clinical or tumour predictors is expected to be extremely low.

CONCLUSIONS

In this study, we observed that age, family history, and histology are imprecise clinical correlates of LS-EC. IHC outperformed MSI for tumour triage and reliably identified both germline and somatic MMR mutations. The 3.2% proportion of LS-EC is similar to colorectal cancer, supporting unselected screening of EC for LS.

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.

Single cell transcriptomes of normal endometrial derived organoids uncover novel cell type markers and cryptic differentiation of primary tumours

Endometrial carcinoma, the most common gynaecological cancer, develops from endometrial epithelium which is composed of secretory and ciliated cells. Pathologic classification is unreliable and there is a need for prognostic tools. We used single cell sequencing to study organoid model systems derived from normal endometrial endometrium to discover novel markers specific for endometrial ciliated or secretory cells. A marker of secretory cells (MPST) and several markers of ciliated cells (FAM92B, WDR16, and DYDC2) were validated by immunohistochemistry on organoids and tissue sections. We performed single cell sequencing on endometrial and ovarian tumours and found both secretory-like and ciliated-like tumour cells. We found that ciliated cell markers (DYDC2, CTH, FOXJ1, and p73) and the secretory cell marker MPST were expressed in endometrial tumours and positively correlated with disease-specific and overall survival of endometrial cancer patients. These findings suggest that expression of differentiation markers in tumours correlates with less aggressive disease, as would be expected for tumours that retain differentiation capacity, albeit cryptic in the case of ciliated cells. These markers could be used to improve the risk stratification of endometrial cancer patients, thereby improving their management. We further assessed whether consideration of MPST expression could refine the ProMiSE molecular classification system for endometrial tumours. We found that higher expression levels of MPST could be used to refine stratification of three of the four ProMiSE molecular subgroups, and that any level of MPST expression was able to significantly refine risk stratification of the copy number high subgroup which has the worst prognosis. Taken together, this shows that single cell sequencing of putative cells of origin has the potential to uncover novel biomarkers that could be used to guide management of cancers. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Clinical relevance of high-intermediate risk endometrial cancer according to European risk classification

OBJECTIVE

Risk models in endometrial cancer define prognosis and indicate adjuvant therapy. One of the currently used classifications was designed in 2016 in collaboration with the European Society of Medical Oncology (ESMO), the European Society of Gynecologic Oncology (ESGO), and the European Society of Radiotherapy (ESTRO). A high-intermediate risk group was introduced within the intermediate risk group. The purpose of this study was to evaluate the clinical relevance of this subclassification.

METHODS

A multicenter retrospective study was carried out at five international tertiary institutions. Patients diagnosed with intermediate risk endometrial cancer on the basis of definitive pathology findings were included. Patients were stratified into intermediate and high-intermediate risk groups. Incidence of nodal metastases, and disease free and overall survival were compared between the two risk groups in univariate and multivariate analysis.

RESULTS

477 patients were included: 325 (68%) patients were identified as intermediate and 152 (32%) as high-intermediate endometrial cancer patients. Nodal metastases were found in 18 patients (11.8%) in the high-intermediate risk endometrial cancer group and 16 patients (4.9%) in the intermediate risk group. Lymphovascular space invasion was found to be a strong predictive factor of lymph node involvement. High-intermediate risk was found to be an independent factor of disease free survival (hazard ratio (HR) 1.76; 95% confidence interval (CI) 1.00 to 3.08; p=0.050) and overall survival (HR 1.99; 95% CI 1.10 to 3.60; p=0.022) in the multivariate analysis.

CONCLUSIONS

The study validates the clinical significance of the intermediate risk endometrial cancer subclassification. Prognosis for high-intermediate risk endometrial cancer was significantly poorer. The prevalence of lymph node metastases was higher in this group of patients.

POLE mutation combined with microcystic, elongated and fragmented (MELF) pattern invasion in endometrial carcinomas might be associated with poor survival in Chinese women

OBJECTIVE

POLE mutation is a prognostic marker associated with excellent outcome in endometrial carcinoma (EC). However, these EC tumors frequently have aggressive histology. The aim of this study was to determine how to integrate the implications of POLE mutations into existing risk assessment strategies and further stratify patients.

METHODS

We detected POLE mutations in a cohort of 426 ECs from Chinese women and observed their prognostic significance in terms of survival and recurrence outcomes in combination with histological and other molecular characteristics, including microcystic, elongated and fragmented (MELF) pattern invasion, histologic subtype, tumor grade, myometrial invasion and p53 protein and mismatch repair protein expression status.

RESULTS

POLE mutations were identified in 38 of 426 ECs (8.9%). The most common mutations were P286R (31.6%), V411L (15.8%) and Q453R (15.8%). We confirmed that POLE mutation was associated with improved overall survival (P = .047), although it did not show a statistically significant relationship with progression-free survival (P = .45). Interestingly, further analyses indicated that in POLE-mutant tumors, MELF pattern invasion was associated with a 15.1-fold increase in tumor recurrence or progression risk (HR = 15.1, 95%CI = 1.57-145.3, P = .018), whereas this phenomenon was not present in the POLE-wild-type subgroup (HR = 0.90, 95%CI = 0.39-2.08, P = .80). Furthermore, higher staging and deeper myometrial invasion also showed much higher risk in patients harboring POLE mutations compared with those without POLE mutations.

CONCLUSIONS

Although POLE mutation was associated with favorable overall survival, the combined consideration of POLE mutation status and established clinicopathologic factors in the risk assessment of endometrial cancer is more accurate than the consideration of clinicopathologic factors alone and might lead to precise and individualized therapeutic strategies.

Incorporation of molecular characteristics into endometrial cancer management

Histopathological evaluation including subtyping and grading is the current cornerstone for endometrial cancer (EC) classification. This provides clinicians with prognostic information and input for further treatment recommendations. Nonetheless, patients with histologically similar ECs may have very different outcomes, notably in patients with high‐grade endometrial carcinomas. For endometrial cancer, four molecular subgroups have undergone extensive studies in recent years: POLE ultramutated (POLEmut), mismatch repair‐deficient (MMRd), p53 mutant (p53abn) and those EC lacking any of these alterations, referred to as NSMP (non‐specific molecular profile). Several large studies confirm the prognostic relevance of these molecular subgroups. However, this ‘histomolecular’ approach has so far not been implemented in clinical routine. The ongoing PORTEC4a trial is the first clinical setting in which the added value of integrating molecular parameters in adjuvant treatment decisions will be determined. For diagnostics, the incorporation of the molecular parameters in EC classification will add a level of objectivity which will yield biologically more homogeneous subclasses. Here we illustrate how the management of individual EC patients may be impacted when applying the molecular EC classification. We describe our current approach to the integrated diagnoses of EC with a focus on scenarios with conflicting morphological and molecular findings. We also address several pitfalls accompanying the diagnostic implementation of molecular EC classification and give practical suggestions for diagnostic scenarios.

Metabolomic Biomarkers for Detection, Prognosis and Identifying Recurrence in Endometrial Cancer

Metabolic reprogramming is increasingly recognised as one of the defining hallmarks of tumorigenesis. There is compelling evidence to suggest that endometrial cancer develops and progresses in the context of profound metabolic dysfunction. Whilst the incidence of endometrial cancer continues to rise in parallel with the global epidemic of obesity, there are, as yet, no validated biomarkers that can aid risk prediction, early detection, prognostic evaluation or surveillance. Advances in high-throughput technologies have, in recent times, shown promise for biomarker discovery based on genomic, transcriptomic, proteomic and metabolomic platforms. Metabolomics, the large-scale study of metabolites, deals with the downstream products of the other omics technologies and thus best reflects the human phenotype. This review aims to provide a summary and critical synthesis of the existing literature with the ultimate goal of identifying the most promising metabolite biomarkers that can augment current endometrial cancer diagnostic, prognostic and recurrence surveillance strategies. Identified metabolites and their biochemical pathways are discussed in the context of what we know about endometrial carcinogenesis and their potential clinical utility is evaluated. Finally, we underscore the challenges inherent in metabolomic biomarker discovery and validation and provide fresh perspectives and directions for future endometrial cancer biomarker research.

Targeted therapies in gynecological cancers: a comprehensive review of clinical evidence

Advanced and recurrent gynecological cancers are associated with poor prognosis and lack of effective treatment. The developments of the molecular mechanisms on cancer progression provide insight into novel targeted therapies, which are emerging as groundbreaking and promising cancer treatment strategies. In gynecologic malignancies, potential therapeutic targeted agents include antiangiogenic agents, poly (ADP-ribose) polymerase (PARP) inhibitors, tumor-intrinsic signaling pathway inhibitors, selective estrogen receptor downregulators, and immune checkpoint inhibitors. In this article, we provide a comprehensive review of the clinical evidence of targeted agents in gynecological cancers and discuss the future implication.

POLE Mutation Characteristics in a Chinese Cohort with Endometrial Carcinoma

Objective

To study the characteristics of polymerase epsilon (POLE) exonuclease domain mutations in Chinese patients with endometrial carcinoma (EC).

Methods

This study analyzed data from 529 patients with EC in The Cancer Genome Atlas (TCGA) and 467 EC patients evaluated at the Shanghai First Maternity and Infant Hospital (SFMIH). POLE mutation heterogeneity was analyzed in paired curettage and hysterectomy samples from 120 SFMIH patients. Sanger sequencing identified mutations in the POLE exonuclease domain, and correlations between POLE mutation status and various clinicopathological features were determined by chi-squared testing and Cohen’s kappa analysis, with Kaplan–Meier survival curves generated to assess correlations between POLE mutation status and overall survival (OS).

Results

Thirty-five mutations were identified in 467 samples (7.5%), and novel mutations were detected in the SFMIH cohort. Compared to the TCGA cohort, the SFMIH cohort had fewer POLE mutations when matched by age (<60) and histology (endometrioid) (p < 0.001 and p = 0.010, respectively). In our study cohort, POLE mutations were significantly associated with adjuvant treatment (p = 0.029), and patients with POLE mutations who underwent chemoradiotherapy had a poor OS (p < 0.0001). Notably, shorter OS was significantly associated with POLE mutations in hysterectomy samples from patients aged >60 years or with stage I disease in the paired curettage-hysterectomy group.

Conclusion

The significant difference in POLE mutation profiles between the TCGA and SFMIH cohorts, as well as the poor consistency between the curettage and hysterectomy samples, suggests that different parameters need to be applied to determine the prognosis of patients with EC in China.

Identification of core genes in the progression of endometrial cancer and cancer cell-derived exosomes by an integrative analysis

Endometrial cancer is one of the most prevalent tumors of the female reproductive system causing serious health effects to women worldwide. Although numerous studies, including analysis of gene expression profile and cellular microenvironment have been reported in this field, pathogenesis of this disease remains unclear. In this study, we performed a system bioinformatics analysis of endometrial cancer using the Gene Expression Omnibus (GEO) datasets (GSE17025, GSE63678, and GSE115810) to identify the core genes. In addition, exosomes derived from endometrial cancer cells were also isolated and identified. First, we analyzed the differentially expressed genes (DEGs) between endometrial cancer tissues and normal tissues in clinic samples. We found that HAND2-AS1, PEG3, OGN, SFRP4, and OSR2 were co-expressed across all 3 datasets. Pathways analysis showed that several pathways associated with endometrial cancer, including "p53 signaling pathway", "Glutathione metabolism", "Cell cycle", and etc. Next, we selected DEGs with highly significant fold change and co-expressed across the 3 datasets and validated them in the TCGA database using Gene Expression Profiling Interactive Analysis (GEPIA). Finally, we performed a survival analysis and identified four genes (TOP2A, ASPM, EFEMP1, and FOXL2) that play key roles in endometrial cancer. We found up-regulation of TOP2A and ASPM in endometrial cancer tissues or cells, while EFEMP1 and FOXL2 were down-regulated. Furthermore, we isolated exosomes from the culturing supernatants of endometrial cancer cells (Ishikawa and HEC-1-A) and found that miR-133a, which regulates expression of FOXL2, were present in exosomes and that they could be delivered to normal endometrial cells. The common DEGs, pathways, and exosomal miRNAs identified in this study might play an important role in progression as well as diagnosis of endometrial cancer. In conclusion, our results provide insights into the pathogenesis and risk assessment of endometrial cancer. Even so, further studies are required to elucidate on the precise mechanism of action of these genes in endometrial cancer.

Wnt Signaling in Gynecologic Malignancies

Gynecologic malignancies, including ovarian cancer, endometrial cancer, and cervical cancer, affect hundreds of thousands of women worldwide every year. Wnt signaling, specifically Wnt/β-catenin signaling, has been found to play an essential role in many oncogenic processes in gynecologic malignancies, including tumorigenesis, metastasis, recurrence, and chemotherapy resistance. As such, the Wnt/β-catenin signaling pathway has the potential to be a target for effective treatment, improving patient outcomes. In this review, we discuss the evidence supporting the importance of the Wnt signaling pathways in the development, progression, and treatment of gynecologic malignancies.

Adjuvant treatment of endometrial cancer in molecular era: Are we ready to move on?

For many decades, the Bokhman dualist vision was used to stratify endometrial cancer (EC) in good or bad tumors. Nowadays, a more robust and reliable molecular stratification is taking place with the The Cancer Genome Atlas Research Network (TCGA) classification bringing new and important information in the field. Collaborative groups are replicating TCGA using accessible tools with immunohistochemistry. It's time to move on and include this information along with pathology features to better delineate adjuvant treatment in EC.

TCGA Classification of Endometrial Cancer: the Place of Carcinosarcoma

In 2013, The Cancer Genome Atlas (TCGA) Research Network found four novel prognostic subgroups of endometrial carcinoma: POLE/ultramutated (POLE), microsatellite-instable/hypermutated (MSI), copy-number-low/TP53-wild-type (CNL), and copy-number-highTP53-mutant (CNH). However, poor is known regarding uncommon histotypes of endometrial cancer. We aimed to assess the genetic profile of uterine carcinosarcoma (UCS) on the light of these findings. A systematic review and meta-analysis was performed through electronic databases searching (up to July 2019). All studies assessing UCS series for the TCGA classification were included. For each TCGA subgroup, pooled prevalence on the total UCS number was calculated. Four studies with 231 patients were included. Pooled prevalence of the TCGA subgroups were: 5.3% for the POLE subgroup, 7.3% for the MSI subgroup, 73.9% for the CNH subgroup, 13.5% for the CNL subgroup. The CNH subgroup predominates in UCS, while subgroups with high mutational load (POLE and MSI) are less common. UCS appears as a preferential evolution of CNH carcinomas.