OBJECTIVE: Molecular classification according to The Cancer Genome Atlas (TCGA) improves endometrial endometrioid carcinoma (EEC) prognostication and has specific treatment implications; however, original data were skewed towards low-grade and low-stage tumours. Herein, we molecularly classify EECs metastatic at the time of diagnosis or with subsequently documented recurrent/metastatic disease to examine correlation with clinical outcomes.
METHODS: TCGA categories include POLE-mutated, microsatellite instability (MSI), p53 abnormal (p53 abnl) and no specific molecular profile (NSMP). POLE targeted sequencing at exons 9, 11, 13 and 14 and immunohistochemistry (IHC) for PMS2, MSH6 and p53 were performed to establish molecular classification.
RESULTS: The distribution in our cohort of 141 EECs was similar to that generally reported in EEC, with nine POLE-mutated (6%), 45 MSI (32%), 16 p53 abnl (11%) and 71 NSMP (50%), with similar distributions between low- and high-stage cohorts. We demonstrate that when stratified by molecular subtype, disease-specific survival from the time of high-stage (stages III-IV) presentation or time of recurrence in low-stage (stages I-II) disease among metastatic and/or recurrent EEC is strongly associated with TCGA classification (high-stage P = 0.02, low-stage P = 0.017). Discordant molecular classification between primary and metastatic/recurrent tumours occurred in four of 105 (3.8%) patients, two related to PMS2/MSH6 IHC and two related to p53 IHC.
CONCLUSIONS: We demonstrate that molecular classification is prognostically relevant not only at the time of diagnosis, but also at the time of recurrence and in the metastatic setting. Rare subclonal alterations occur and suggest a role for confirming TCGA classification in recurrent/metastatic tumours.

The hyperplasia-carcinoma sequence is a stepwise tumourigenic programme towards endometrial cancer in which normal endometrial epithelium becomes neoplastic through non-atypical endometrial hyperplasia (NAEH) and atypical endometrial hyperplasia (AEH), under the influence of unopposed oestrogen. NAEH and AEH are known to exhibit polyclonal and monoclonal cell growth, respectively; yet, aside from focal PTEN protein loss, the genetic and epigenetic alterations that occur during the cellular transition remain largely unknown. We sought to explore the potential molecular mechanisms that promote the NAEH-AEH transition and identify molecular markers that could help to differentiate between these two states. We conducted target-panel sequencing on the coding exons of 596 genes, including 96 endometrial cancer driver genes, and DNA methylome microarrays for 48 NAEH and 44 AEH lesions that were separately collected via macro- or micro-dissection from the endometrial tissues of 30 cases. Sequencing analyses revealed acquisition of the PTEN mutation and the clonal expansion of tumour cells in AEH samples. Further, across the transition, alterations to the DNA methylome were characterised by hypermethylation of promoter/enhancer regions and CpG islands, as well as hypo- and hyper-methylation of DNA-binding regions for transcription factors relevant to endometrial cell differentiation and/or tumourigenesis, including FOXA2, SOX17, and HAND2. The identified DNA methylation signature distinguishing NAEH and AEH lesions was reproducible in a validation cohort with modest discriminative capability. These findings not only support the concept that the transition from NAEH to AEH is an essential step within neoplastic cell transformation of endometrial epithelium but also provide deep insight into the molecular mechanism of the tumourigenic programme. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Endometrioid endometrial carcinoma (EEC) stands as a prevalent gynecologic malignancy in developed regions. However, predicting relapse cases remains challenging, necessitating the identification of a novel biomarker for EEC relapse. The assessment of tumor mutational burden (TMB) is pivotal for immunotherapy in EEC patients. However, both whole-exome sequencing (WES) and targeted sequencing encountered application-related difficulties. In light of this, standardized and simplified techniques for TMB measurement are imperative. In this study, we employed WES on 25 EEC patients (12 relapsed cases and 13 non-relapsed cases) who accepted hysterectomy surgery (CHCAMS cohort). We additionally obtained a total of 391 tumor samples with clinicopathological features from TCGA website to broaden the study cohort. In the CHCAMS cohort, the TTN mutant group showed shorter progression-free survival (p < 0.001) and overall survival (p < 0.001) than TTN wild-type group. Additionally, we discovered that the number of TTN mutations per sample was significantly linked with TMB-WES in CHCAMS cohort and TCGA cohort (p < 0.05). And the number of TTN mutations per sample in POLE mutant group was greater than in the POLE wild-type group (p < 0.0001). In conclusion, TTN mutation may serve as a biomarker for EEC prognosis. TTN mutation is also associated with WES-TMB, and could be a simplified TMB measurement technique.

To evaluate the role of serum human epididymis secretory protein 4 (HE4) and carbohydrate antigen 125 (CA125) levels for predicting and monitoring the recurrence of endometrial endometrioid carcinoma (EEC) and assessing preoperative risk stratification in EEC patients. A total of 434 EEC patients were selected for this retrospective study between May 2011 and August 2018. Serum HE4 and CA125 levels were analyzed before the initial treatment, at the first postoperative follow-up, and at recurrence or the last follow-up. Patients were risk stratified according to the European Society for Medical Oncology (ESMO), European Society for Radiotherapy & Oncology (ESTRO) and European Society of Gynaecological Oncology (ESGO) guideline. We compared the ability of these biomarkers for prediction and monitoring by performing receiver operating characteristic curve analysis and identified optimal cut-off values by determining the Youden index. Kaplan-Meier analyses were also performed to determine prognostic value. Preoperative serum HE4 was identified as a significant predictor for the recurrence of EEC (p = 0.014). Preoperative serum HE4 and CA125 levels were related to depth of myometrial invasion, lymph node status and FIGO stage. Serum HE4 and CA125 levels were both statistically significant markers for monitoring the recurrence of EEC (P = 0.000 for each biomarker). When combined, the two markers showed higher levels of sensitivity and specificity. The two biomarkers were also significant biomarkers for evaluating the risk stratification of patients undergoing lymphadenectomy (P = 0.000 for each biomarker). For premenopausal stage I patients, preoperative serum HE4 and CA125 levels were significant predictors of the need for ovarian preservation (P = 0.000 and P = 0.002, respectively). For premenopausal patients with stage I intramucosal differentiation, preoperative serum levels of HE4 were significant predictors for fertility preservation (P = 0.024). Preoperative serum HE4 level can be used to predict the recurrence of EEC. Postoperative serum HE4 and CA125 levels can be used to monitor the recurrence of EEC and are more sensitive when combined. Preoperative serum levels of CA125 and HE4 levels are of significant value for risk stratification in EEC patients.

Loss of progesterone receptor (PR) expression is an established risk factor for unresponsiveness to progesterone therapy in patients with endometrial atypical hyperplasia and endometrioid carcinoma. ARID1A is one of the most commonly mutated genes in endometrioid carcinomas, and the loss of its expression is associated with tumor progression. In this study, we investigated the roles of ARID1A deficiency in PR expression in human and murine endometrial epithelial neoplasia. An analysis of genome-wide chromatin immunoprecipitation sequencing in isogenic ARID1A-/- and ARID1A+/+ human endometrial epithelial cells revealed that ARID1A-/- cells showed significantly reduced chromatin immunoprecipitation sequencing signals for ARID1A, BRG1, and H3K27AC in the PgR enhancer region. We then performed immunohistochemistry to correlate the protein expression levels of ARID1A, estrogen receptor, and PR in 50 human samples of endometrial atypical hyperplasia and 75 human samples of endometrial carcinomas. The expression levels of PR but not were significantly lower in ARID1A-deficient low-grade endometrial carcinomas and atypical hyperplasia (P = .0002). When Pten and Pten/Arid1a conditional knockout murine models were used, Pten-/-;Arid1a-/- mice exhibited significantly decreased epithelial PR expression in endometrial carcinomas (P = .003) and atypical hyperplasia (P < .0001) compared with that in the same tissues from Pten-/-;Arid1a+/+ mice. Our data suggest that the loss of ARID1A expression, as occurs in ARID1A-mutated endometrioid carcinomas, decreases PgR transcription by modulating the PgR enhancer region during early tumor development.

The incidence of endometrial endometrioid carcinoma (EEC) has been gradually increasing over the past decade. Fertility-sparing therapy with progestin is a treatment option for EEC or endometrial atypical hyperplasia (AH). The present study evaluated the role of numerous prognostic factors following fertility-sparing therapy for EEC or AH. Furthermore, the present study assessed the strength of various clinicopathological indicators for the prediction of treatment efficacy. A retrospective analysis was performed of patients with EEC and AH who received fertility-sparing therapy between August 2013 and September 2021 at Peking University People\'s Hospital (Beijing, China). Endometrial specimens were obtained from each patient after 3 months of treatment and at the end of the fertility-sparing therapy, before treatment efficacy and prognosis were evaluated using the χ2 test. Furthermore, the protein expression levels of EEC biomarkers, such as estrogen receptor (ER), progesterone receptor (PR), paired box 2 (PAX2), PTEN and p53 were assessed using immunohistochemistry. The overall complete response (CR) rate of fertility-sparing treatment in the EEC group was 67.39% (31/46), whereas that in the AH group was 86.49% (32/37). The difference between the CR rates in the EEC and AH groups was statistically significant (P<0.05). There was no association between prognosis after treatment and ER, PAX2, PTEN or Ki-67 expression in the initially untreated AH or EEC groups. However, tissues with >50% positive PR expression were demonstrated to have a higher CR rate compared with those with ≤50% positive PR expression in both the EEC and AH groups. Furthermore, the PAX2-positive group tended to demonstrate higher CR rates compared with the PAX2-negative group in the patients with EEC. In conclusion, these data suggested that fertility-sparing therapy is effective for patients with EEC and AH who wish to remain fertile after treatment. Specifically, in the AH group, a higher proportion of patients achieved a CR whilst also achieving this more rapidly. Furthermore, PR was demonstrated to be a useful marker for the evaluation of EEC and AH.

Endometrioid endometrial carcinomas (EEC) are common malignant lesions of the female genital tract, with incidence and risk factors that raise issues to improve histopathological prognostic factors. The study included 50 EEC cases, for which the clinicopathological parameters represented by age, risk factors, tumor grade, histological differences, invasion pattern, tumor stage and association of endometrial hyperplasia were analyzed statistically. The results indicated the predominance of EEC in the 7th decade of life, with associated risk factors (78%), more frequently well differentiated (52%), with no other specifications related to differentiation (NOS, 60%), with irregular invasion pattern (66%) in<50% of the myometrial wall (48%). Irregular pattern, microcystic, elongated, and fragmented (MELF) pattern and myoinvasion associated with vascular invasion (MVI) pattern were significantly associated with high grade and advanced stage tumors. With the exception of EEC-NOS and squamous differentiation, all other tumors were associated with low grade (G1). In this study there was a tendency to associate the age group of 60-69 years with the presence of endometrial hyperplasia and with high grade and advanced stage. Apart from the high grade and advanced stage, in the aggressive profile of the EEC can be included as the clinicopathological parameters the 7th decade of life and the irregular, MELF and MVI invasion patterns.

BACKGROUND: In Japan, the direct smearing preparation (conventional preparation) has been widely used for cytological examination of the endometrium. Problems with the conventional preparation can be dissolved by liquid-based cytology (LBC) preparation. The Yokohama System is a method for reporting endometrial cytology, but the system lumps cancers together and does not distinguish between histological types. The objective of this study was to clarify morphometrical differences among endometrial endometrioid carcinoma grade 1 (G1), grade 3 (G3), and serous carcinoma (Serous) by image analysis of endometrial LBC.
METHODS: Using Papanicolaou smears prepared by LBC after sampling with a brush from 32 G1, 16 G3, and 16 Serous patients, image analysis was performed concerning the following 11 items: (1) number of layers of cluster, (2) area of cluster, (3) perimeter of cluster, (4) roundness of cluster, (5) complexity of cluster, (6) area of nucleus, (7) perimeter of nucleus, (8) roundness of nucleus, (9) complexity of nucleus, (10) area of nucleolus, and (11) nucleolus/nucleus (N/N) ratio. The data were statistically compared among G1, G3, and Serous.
RESULTS: Significant differences were observed in the number of layers of cluster (G1G3G3, G1>Serous), complexity of cluster (G1Serous), and N/N ratio (G1>G3, G3CONCLUSIONS: The number of layers and area of cluster, complexity of cluster, area and complexity of nucleus, area of nucleolus, and N/N ratio were suggested to be useful for the differentiation of histological types among G1, G3, and Serous. Particularly, differences in the number of layers of cluster, size of nucleus, and size of nucleolus among histological types were large and are considered to be potentially effective points of differential diagnosis.

BACKGROUND: The balance of pro- and anti-apoptotic proteins plays a critical role in the regulation of cell death, and a disruption of this delicate balance may eventuate in carcinogenesis through a net reduction in apoptosis. Numerous chemotherapeutic strategies directly or indirectly target apoptotic pathways. However, a thorough assessment of apoptosis-related proteins has not previously been performed in endometrial clear cell carcinoma (CCC). This study aims to determine the significance of 9 apoptosis-related proteins in the pathogenesis of CCC as compared to non-neoplastic endometrium (NNE), low- and high-grade endometrial endometrioid carcinomas (LG-EEC, HG-EEC), and endometrial serous carcinoma (ESC).
METHODS: Expression of 6 anti-apoptotic proteins (Bcl-2, Bcl-xL, cFLIPL, MCL-1, survivin, NFκB/p65) and three pro-apoptotic proteins (Bax, caspase-3, caspase-8) was assessed by immunohistochemistry on 49 CCC, 37 LG-EEC, 12 HG-ECC, 16 ESC, and 25 NNE in a tissue microarray. Objective IHC scores were assigned by an automated image capture system. Scores were then correlated with clinicopathologic values and each other.
RESULTS: Most notably, CCC showed significantly reduced expression of cFLIPL relative to ESC, LG-EEC, HG-EEC, and NNE. CCC also showed significantly reduced expression of both Caspase 8 and NF-κB/p65 relative to ESC, HG-EEC, and NNE, but not LG-EEC. Bcl-2 and Bcl-xL showed reduced expression in CCC relative to all groups except ESC for Bcl-2 and NNE for Bcl-xL. There was no significant correlation between the proteins regarding expression levels. Within the CCC group, none of the proteins showed any significant association with patient age, myometrial invasion, final stage, lymphovascular invasion, disease-free or overall survival.
CONCLUSIONS: Our analysis of the expression and correlation patterns of a panel of apoptosis-related proteins suggests that the downregulation of cFLIPL in CCC is significant relative to almost all other tissues, NNE, HG-EEC, and ESC. Other proteins, including Caspase 8, NF-κB/p65, Bcl-2 and Bcl-xL may also be significant. The regulation of apoptosis-related proteins in CCC may be important and may provide insight into chemoresistance in this enigmatic histotype. However, the paradoxical downregulation of both pro- and anti-apoptotic mediators suggests that additional study is needed to clarify the role of apoptotic mechanisms in CCC.

OBJECTIVE: Endometrial endometrioid carcinoma (EEC) is the most encountered subtype of endometrial cancer (EC). Our study aimed to investigate the factors affecting recurrence in patients with stage 1A and 1B EEC.
METHODS: Our study included 284 patients diagnosed with the International Federation of Gynecology and Obstetrics stage 1A/1B EEC in our center from 2010 to 2018. The clinicopathological characteristics of the patients were obtained retrospectively from their electronic files.
RESULTS: The median age of the patients was 60 years (range 31-89). The median follow-up time of the patients was 63.6 months (range 3.3-185.6). Twenty-two (7.74%) patients relapsed during follow-up. Among the relapsed patients, 59.1% were at stage 1A ECC, and 40.9% were at stage 1B. In our study, the one-, three-, and five-year recurrence-free survival (RFS) rates were 98.9%, 95.4%, and 92.9%, respectively. In the multivariate analysis, grade and tumor size were found to be independent parameters of RFS in all stage 1 EEC patients. Furthermore, the Ki-67 index was found to affect RFS in stage 1A EEC patients, and tumor grade affected RFS in stage 1B EEC patients. In the time-dependent receiver operating characteristic curve analysis, the statistically significant cut-off values were determined for tumor size and Ki-67 index in stage 1 EEC patients.
CONCLUSIONS: Stage 1-EEC patients in the higher risk group in terms of tumor size, Ki-67, and grade should be closely monitored for recurrence. Defining the prognostic factors for recurrence in stage 1 EEC patients may lead to changes in follow-up algorithms.