Clinicopathological and molecular characterization of high-grade endometrial carcinoma with POLE mutation: a single center study

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.

Meta-analysis of the clinicopathologic features of endometrial cancer molecular staging

Objective

The 2013 TCGA identified four molecular subgroups of endometrial cancer; however, the data results for most of the pathological features were varied and of low value for clinical application. Therefore, a meta-analysis of articles related to the clinicopathological features of molecular typing was performed to observe how the prevalence of the four subgroups varied across different pathological features and whether they were associated with certain specific pathological features and to understand how molecular typing may influence current pathological assessments.

Methods

PubMed, Embase, Web of Science, CNKI, Wanfang, and VIP were searched from the time of library construction until May 2024, and the following data were extracted: histological type, FIGO grade, FIGO stage, LVSI, depth of muscularis propria infiltration, and lymph node status of each TCGA group. Two reviewers used the Cochrane Diagnostic Research Scale assessment, and the data were analyzed using Review Manager 5.4.1 and Stata 14.0.

Results

Fourteen diagnostic research papers were included in this study, with a total of 4,776 patients with endometrial cancer. Non-estrogen-related endometrial carcinoma (NEEC) vs. estrogen-related endometrial carcinoma (EEC) was low in polymerase epsilon (POLE) (OR = 0.49), microsatellite instability (MSI) (OR = 0.45), and copy number low (CNL) (OR = 0.11), while it was high in CNH (OR = 26.76). G3 EEC vs. G1-2 EEC POLE (OR = 1.98), MSI (OR = 1.74), and CNH (OR = 5.57) were high, whereas it was low in CNL (OR = 0.23), low in FIGO II-IV vs. FIGO I in POLE (OR = 0.39) and CNH (OR = 0.64), and high in FIGO II-IV vs. FIGO I in CNH (OR = 3.05). There was no difference in MSI prevalence in FIGO II-IV vs. FIGO I. POLE (OR = 0.64) and CNL (OR = 0.75) were low in myometrial invasion depths ≥50% and lower in myometrial invasion depths <50%, and CNL (OR) was higher in CNH (OR) than in myometrial invasion depths <50%. There was no difference in MSI between different myometrial invasion depths. MSI (OR = 1.69) and CNH (OR = 2.12) were higher in lymphatic vascular infiltration (LVSI) vs. no LVSI; CNL (OR = 0.39) was lower in LVSI than in no LVSI. There was no difference in POLE in the presence or absence of LVSI. Lymph node metastasis with and without lymph node metastasis in POLE (OR = 0.25) and CNL (OR = 0.31) were lower, and CNH (OR = 3.06) was higher in lymph node metastasis than in no lymph node metastasis. There was no difference in MSI in the presence or absence of lymph node metastasis.

Conclusions

POLE patients predominated in pathological features of early-stage endometrial cancer and had better prognosis. MSI patients were more likely to be found in EEC and G3 EEC as well as LVSI. Nearly half of G3 EEC as well as LVSI were present in MSI patients, and CNH patients were more likely to be found to have pathological features of advanced endometrial cancer and poor prognosis, providing evidence that CNH is a high-risk cancer. Patients with CNL were more likely to be found to have pathological features of early-stage endometrial cancer and good prognosis, and CNL was present in large numbers in both early-stage and late-stage endometrial cancers. CNL does not yet have a precise prognostic value.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42024563661.

Molecular classification of endometrial cancer: Impact on adjuvant treatment planning

Objective

The traditional histopathological analysis of endometrial cancer (EC) is the main risk group classification tool (low, intermediate, high-intermediate, and high) for the implementation of adjuvant treatment. The International Federation of Gynecology and Obstetrics staging system of EC has incorporated a new molecular classification that serves as a new triage tool for optimal treatment planning for these patients. Our study aimed to investigate the prognostic role of the new molecular classification in EC.

Material and Methods

A prospective study was conducted in the 1st Department of Obstetrics and Gynecology from January 1, 2022, to March 30, 2024, and included all new EC cases that presented the multidisciplinary tumor (MDT) board after surgery. We considered the traditional pathologic analysis and new molecular classification after performing tests on microsatellite instability (MSI), DNA polymerase epsilon (POLE) mutation, and p53 immunohistochemistry testing.

Results

The study included 65 patients with presumed early endometrial. All patients underwent surgery and subsequent molecular testing. Among the patients, 35 (54%) had a "positive" result in all of the three markers of molecular classification: 14 patients presented with MSI-H, 5 with POLE gene mutation, and 17 with p53 abnormal expression. One case of multiple classifiers was presented. After the integration of molecular classification, a change was observed in the final MDT board decision in 23 cases (35.4%), including six cases of overtreatment and 17 cases of undertreatment, with statistical significance (P = 0.03469).

Conclusion

The data suggest that the new molecular classification, that is, testing for POLE mutation, MSI, and p53 mutation and for endometrial carcinoma, is a valuable tool for the recurrence risk prognosis and improved planning of adjuvant treatment for EC.

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 endometrial cancer: preliminary experience from a single Portuguese academic center

Background

Since the seminal publication of the TCGA consortium in 2013, the molecular classification of endometrial cancer has been widely accepted as a new and powerful tool to better understand the natural history of this malignancy. Adoption of routine molecular classification around the world has been limited. We sought to demonstrate our initial experience in incorporating the four molecular subtypes for endometrioid carcinomas.

Methods

This was a retrospective analysis at a single center in Portugal. Molecular classification was determined using immunohistochemical staining for MMR and p53 and Sanger Sequencing to determine POLE mutation status as per published PROMISE method. Descriptive statistics were reported.

Results

20 patients with endometrioid histology were included. Median age of the cohort was 64 years (range 45-76). Median Body Mass Index (kg/m2) was 29.81 (range 21.3-43.1). In terms of tumor grading, 16 (80%) of the endometrial carcinomas of the cohort were low-grade (either grade 1 or grade 2). 16 (80%) of the cases were FIGO stage I. Regarding the molecular classification the tumors were classified as: MMRd [n = 6 (30%)]; p53 abn [n = 2 (10%)]; NSMP (n = 10 (50%)), POLE ultramut [n = 2 (10%)].

Conclusion

Despite the small sample size, we were able to show that molecular classification is feasible. To our knowledge this is the first cohort of endometroid endometrial carcinomas fully characterized according to the TCGA classification in Portugal, from one single center.

Molecular profile in endometrial carcinoma: can we predict the lymph node status? A systematic review and meta-analysis

PURPOSE

Molecular classification of endometrial cancer (EC) has become a promising information to tailor preoperatively the surgical treatment. We aimed to evaluate the rate of lymph node metastases (LNM) in patients with EC according to molecular profile.

METHODS

A systematic review and meta-analysis were performed according to PRISMA guidelines by searching in two major electronic databases (PubMed and Scopus), including original articles reporting lymph node metastases according to the molecular classification of EC as categorized in the ESGO-ESMO-ESP guidelines.

RESULTS

Fifteen studies enrolling 3056 patients were included. Pooled prevalence LNM when considering only patients undergoing lymph node assessment was 4% for POLE-mutated (95%CI: 0-12%), 22% for no specific molecular profile (95% CI: 9-39%), 23% for Mismatch repair-deficiency (95%CI: 10-40%) and 31% for p53-abnormal (95%CI: 24-39%).

CONCLUSIONS

The presence of LNM seems to be influenced by molecular classification. P53-abnormal group presents the highest rate of nodal involvement, and POLE-mutated the lowest.

Molecular characterization as new driver in prognostic signatures and therapeutic strategies for endometrial cancer

Endometrial cancer (EC) incidence and mortality rates have been increasing, particularly among young females. Although more than 90% of ECs are sporadic, 5-10% are hereditary, a majority of which occurs within Hereditary Non-Polyposis Colorectal Cancer syndrome (HNPCC) or Lynch syndrome. The traditional histopathological classification differentiates EC between two main groups: type I (or endometrioid) and type II (including all other histopathological subtypes). However, this classification lacks reproducibility and does not account for the emerging molecular heterogeneity. In 2013, The Cancer Genome Atlas (TCGA) project proposed EC molecular classification defining four groups with different prognostic and predictive values and the current international guidelines are progressively establishing EC risk stratification and treatment based on both histopathological and molecular criteria. Our manuscript aims to summarize the current state of EC molecular characterizations, including germline alterations at the basis of hereditary EC predisposition, to discuss their clinical utility as prognostic and predictive markers.

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.

DNA polymerase ε and δ variants drive mutagenesis in polypurine tracts in human tumors

Alterations in the exonuclease domain of DNA polymerase ε cause ultramutated cancers. These cancers accumulate AGA>ATA transversions; however, their genomic features beyond the trinucleotide motifs are obscure. We analyze the extended DNA context of ultramutation using whole-exome sequencing data from 524 endometrial and 395 colorectal tumors. We find that G>T transversions in POLE-mutant tumors predominantly affect sequences containing at least six consecutive purines, with a striking preference for certain positions within polypurine tracts. Using this signature, we develop a machine-learning classifier to identify tumors with hitherto unknown POLE drivers and validate two drivers, POLE-E978G and POLE-S461L, by functional assays in yeast. Unlike other pathogenic variants, the E978G substitution affects the polymerase domain of Pol ε. We further show that tumors with POLD1 drivers share the extended signature of POLE ultramutation. These findings expand the understanding of ultramutation mechanisms and highlight peculiar mutagenic properties of polypurine tracts in the human genome.

Dedifferentiated Endometrial Carcinoma: A Rare Aggressive Neoplasm-Clinical, Morphological and Immunohistochemical Features

Dedifferentiated endometrioid adenocarcinoma is characterised by the coexistence of an undifferentiated carcinoma and a low-grade endometrioid adenocarcinoma. The low-grade component in this subtype of endometrial carcinoma is Grade 1 or 2 according to the Federation of Gynaecology and Obstetrics (FIGO) grading system. The coexistence of low-grade endometrial carcinoma and solid undifferentiated carcinoma can cause diagnostic problems on histological examination. In fact, this combination can often be mistaken for a more common Grade 2 or Grade 3 endometrial carcinoma. Therefore, this subtype of uterine carcinoma can often go under-recognised. An accurate diagnosis of dedifferentiated endometrial carcinoma is mandatory because of its poorer prognosis compared to Grade 3 endometrial carcinoma, with a solid undifferentiated component that can amount to as much as 20% of the entire tumour. The aim of this review is to provide clinical, immunohistochemical, and molecular data to aid with making an accurate histological diagnosis and to establish whether there are any findings which could have an impact on the prognosis or therapeutic implications of this rare and aggressive uterine neoplasm.

Practical lessons learned from real-world implementation of the molecular classification for endometrial carcinoma

OBJECTIVES

This study aimed to explore the practical organisational aspects and difficulties in the implementation of the molecular classification of endometrial carcinoma (EC), and to demonstrate its potential impact in prognostic risk group classification.

METHODS

We conducted a multicentre, retrospective cohort study of 230 patients with EC diagnosed between 2019 and 2022. Sample processing, clinicopathological, treatment and follow-up data were collected. Molecular classification was obtained by p53 and mismatch repair proteins immunohistochemistry, and POLE next-generation sequencing.

RESULTS

Implementation was achieved through centralization of molecular analysis. In practice, it was possible to optimise turnaround times of complete integrative reports for hysterectomy specimens to a median time of 18 workdays. If genetic study was started in endometrial biopsies before surgery, 82.0% were available at the time of multidisciplinary tumour board, compared to 8.4% if performed in hysterectomy. ECs were classified as follows: 37.8% no specific molecular profile, 31.7% p53 abnormal, 24.3% mismatch repair deficient, and 6.1% POLE mutant. Integration of these results with traditional clinicopathologic factors led to a change in prognostic risk group in 15 (6.5%) patients, most being initially allocated to high-intermediate (n = 8) and low (n = 5) risk groups. Eight patients changed to a higher risk, and 7 to a lower risk group, whereas 2 remained in the same group.

CONCLUSIONS

Centralization of EC molecular classification is a feasible option for countries with limited resources. Optimization of workflows may be achieved by earlier analysis in biopsies and prioritisation of patients whose results imply changes in risk group classification.

A novel somatic mutation in POLE exonuclease domain associated with ultra-mutational signature and MMR deficiency in endometrial cancer: a case report

BACKGROUND

Defect in proofreading exonuclease activity of polymerases epsilon and delta (Pols ε and δ) leads to mutagenesis and genomic instability and has been described in several cancer types. Somatic POLE exonuclease domain mutations (EDMs) have been reported in 7-12% endometrial cancers (ECs) and defined a subgroup of endometrial cancers with ultrahigh somatic mutation frequencies, high tumor infiltrated lymphocytes and favorable outcomes.

CASE PRESENTATION

Herein, we presented a novel somatic mutation in POLE exonuclease domain associated with ultra-mutational signature and MMR deficiency in endometrial cancer. A novel POLE EDM (p.T278K) was found by a 11-gene NGS panel. The MSS status detected by the MSI test was inconsistent with the dMMR status by IHC. The loss of MSH6 expression in the tumor could be interpreted by the two nonsense mutations (p.E1234* and p.E1322*) of the MSH6 gene which may lead to truncated proteins. The T278K mutation was pathogenic identified by a 602-gene NGS panel with 27.3% of C > A substitution, 0.6% of indels, 0.6% of C > G substitution and a high TMB of 203.8 mut/Mb.

CONCLUSIONS

We report an endometrial cancer patient harbored a novel somatic POLE T278K mutation. This mutation was a novel pathogenic POLE EDM should be considered as "POLE (ultramutated)" in clinical practice for the molecular classification of EC.

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.

Comprehensive Analysis and Experimental Validation of a Novel Estrogen/Progesterone-Related Prognostic Signature for Endometrial Cancer

Estrogen and progesterone are the major determinants of the occurrence and development of endometrial cancer (EC), which is one of the most common gynecological cancers worldwide. Our purpose was to develop a novel estrogen/progesterone-related gene signature to better predict the prognosis of EC and help discover effective therapeutic strategies. We downloaded the clinical and RNA-seq data of 397 EC patients from The Cancer Genome Atlas (TCGA) database. The “limma” R package was used to screen for estrogen/progesterone-related differentially expressed genes (DEGs) between EC and normal tissues. Univariate and multivariate Cox proportional hazards regression analyses were applied to identify these DEGs that were associated with prognosis; then, a novel estrogen/progesterone-related prognostic signature comprising CDC25B, GNG3, ITIH3, PRXL2A and SDHB was established. The Kaplan–Meier (KM) survival analysis showed that the low-risk group identified by this signature had significantly longer overall survival (OS) than the high-risk group; the receiver operating characteristic (ROC) and risk distribution curves suggested this signature was an accurate predictor independent of risk factors. A nomogram incorporating the signature risk score and stage was constructed, and the calibration plot suggested it could accurately predict the survival rate. Compared with normal tissues, tumor tissues had increased mRNA levels of GNG3 and PRXL2A and a reduced mRNA level of ITIH3. The knockdown of PRXL2A and GNG3 significantly inhibited the proliferation and colony formation of Ishikawa and AN3CA cells, while the inhibition of PRXL2A expression suppressed xenograft growth. In this study, five estrogen/progesterone-related genes were identified and incorporated into a novel signature, which provided a new classification tool for improved risk assessment and potential molecular targets for EC therapies.