Endometrioid Endometrial Carcinoma Research Articles

The analysis of IVF outcomes after fertility-preserving therapy for endometrial hyperplasia or carcinoma.

This study aimed to evaluate the clinical efficacy of fertility-preserving therapy through in vitro fertilization (IVF) procedures in women who were pathologically diagnosed with endometrial hyperplasia or carcinoma. A retrospective cohort study on fertility-preserving therapy was conducted. Participants/Materials, Setting: A total of 82 women were enrolled who had simple endometrial hyperplasia (SH), complex hyperplasia (CH), complex atypical hyperplasia (CAH), and endometrioid endometrial carcinoma stage IA (EC IA) and underwent IVF at Gangnam CHA fertility center between January 2008 and December 2020. The primary endpoints were oncologic outcomes and subsequent reproductive outcomes of patients who underwent fertility-preserving treatments analyzed by χ2 test (chi-square test) or Fisher's exact test. Of the 82 patients, 33 had a cumulative clinical pregnancy (40.2%), and 25 had a cumulative live birth (30.5%) through IVF procedures following pathologic confirmation of complete remission or non-progressive status. The cumulative clinical pregnancy rates and live birth rates for, SH were 50.0% and 30.0%, for CH were 37.8% and 28.9%, for CAH were 25.0% and 25.0%, and for EC were 38.5% and 38.5%, respectively. There were no significant differences in cumulative clinical pregnancy rates or live birth rates when comparing the four groups. There was a difference in endometrial thickness between MPA treatment group and IUD group (p=0.036); however, there were no significant differences in clinical pregnancy rates among MPA, IUD, and MPA+IUD groups. Because of the retrospective nature of the study, many factors relevant to the treatment decision were not strictly controlled. All endometrial hyperplasia and carcinoma groups had competent cumulative live birth rates by IVF procedures. There may be differences in endometrial thickness depending on the treatment methods, but this does not affect clinical pregnancy rates. Therefore, the fertility-preserving treatment for endometrial hyperplasia and carcinoma is a safe and feasible method that results in good IVF outcomes.

Genetic and epigenetic alterations in precursor lesions of endometrial endometrioid carcinoma.

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.

Validating the 2023 FIGO staging system: A nomogram for endometrioid endometrial cancer and adenocarcinoma.

To find the factors impacting overall survival (OS) prognosis in patients with endometrioid endometrial carcinoma (EEC) and adenocarcinoma and to establish a nomogram model to validate the 2023 International Federation of Obstetrics and Gynecology (FIGO) staging system for endometrial cancer. Data were obtained from the Surveillance, Epidemiology, and End Results (SEER) training cohort. An independent validation cohort was obtained from the First Affiliated Hospital of Anhui Medical University between 2008 and 2023. Cox regression analysis identified independent prognostic factors for OS in EEC and adenocarcinoma patients. A nomogram predicting OS was developed and validated utilizing the C-index, calibration curves, receiver operating characteristic (ROC) curves, and decision curve analysis (DCA). The relationship between the tumor grade and prognosis of EEC and adenocarcinoma was quantified using net reclassification improvement (NRI), propensity score matching (PSM), and Kaplan-Meier curves. Cox regression analysis identified age, race, marital status, tumor grade, tumor stage, tumor size, and chemotherapy as independent prognostic factors for OS. A nomogram for predicting OS was developed based on these factors. The C-indexes for the OS nomogram was 0.743 and 0.720 for the SEER training set and external validation set, respectively. The area under the ROC (AUC) for the OS nomogram was 0.755, 0.757, and 0.741 for the SEER data subsets and 0.844, 0.719, and 0.743 for the external validation subsets. Calibration plots showed high concordance between the nomogram-predicted and observed OS. DCA also demonstrated the clinical utility of the OS nomogram. NRI, PSM, and survival analyses revealed that tumor grade was the most important histopathological factor for EEC and adenocarcinoma prognosis. Seven independent prognostic variables for the OS of patients with EEC and adenocarcinoma were identified. The established OS nomogram has good predictive ability and clinical utility and validates the 2023 endometrial cancer FIGO staging system.

Morular Metaplasia of the Endometrium: A Case Report and Literature Review: Care Pathways based on Molecular Biology

Background: Endometrial morular metaplasia, a clinical conundrum from a diagnostic and management angle given its rarity and low oncogenic potential has been linked to endometrial hyperplasia and carcinoma. Case report: A 77-year-old woman with no significant past medical history was found to have an asymptomatic thickened endometrium on pelvic imaging, after presenting with lower abdominal pain, 3 yrs ago. Diagnostic hysteroscopy identified an endometrial polyp within a pyometra. Histopathology showed focal complex hyperplasia without atypia with superimposed morular metaplasia (EMM) amongst negative microbiology. Following conservative management with a Multidisciplinary Team (MDT) overview, as per her choice with 6-monthly follow-up hysteroscopies, endometrial biopsies, and a short use of the Mirena IUS (discontinued due to poor tolerance), histopathology shows resolved hyperplasia with persistent EMM. She is considering a hysterectomy. Discussion: Current evidence suggests that a sub-type of EMM, a likely histological manifestation of beta-catenin (CTNNB1) gene mutation: could be a precursor of endometrial hyperplasia and low-grade endometrioid-endometrial carcinoma sub-type. Though low-grade in nature, the increased recurrence risk raises significant concerns. Management options which include conservative, hormonal, and surgery have been described in the literature. A few cases of premenopausal women have been managed conservatively, with one resulting in a pregnancy. However, due to the lack of a natural history timeline, the optimal frequency of endometrial sampling when uterine-sparing, is unclear, leading to a management conundrum. Conclusion: Management of morular endometrial metaplasia can be difficult but must reflect the woman’s choice with an MDT overview. Immuno-histochemical tools utilizing new molecular biological advances can simplify the diagnostic and prognostication processes, aiding clinical management.

Endometrioid Endometrial RNA Index Predicts Recurrence in Stage I Patients.

Risk prediction with genomic and transcriptomic data has the potential to improve patient outcomes by enabling clinicians to identify patients requiring adjuvant treatment approaches, while sparing low-risk patients from unnecessary interventions. Endometrioid endometrial carcinoma (EEC) is the most common cancer in women in developed countries, and rates of endometrial cancer are increasing. We collected a 105-patient case-control cohort of stage I EEC comprised of 45 patients who experienced recurrence less than 6 years after excision, and 60 FIGO grade matched controls without recurrence. We first utilized two RNA based, previously validated machine learning approaches, namely EcoTyper and Complexity Index in Sarcoma (CINSARC). We developed Endometrioid Endometrial RNA Index (EERI) which uses RNA expression data from 46 genes to generate a personalized risk score for each patient. EERI was trained on our 105-patient cohort and tested on a publicly available cohort of 263 stage I EEC patients. EERI was able to predict recurrences with 94% accuracy in the training set and 81% accuracy in the test set. In the test set, patients assigned as EERI high-risk were significantly more likely to experience recurrence (30%) than the EERI low-risk group (1%) with a hazard ratio of 9.9 (95% CI 4.1-23.8, P <0.001). Tumors with high-risk genetic features may require additional treatment or closer monitoring and are not readily identified using traditional clinicopathologic and molecular features. EERI performs with high sensitivity and modest specificity, which may benefit from further optimization and validation in larger independent cohorts.

TTN Mutation in Endometrial Endometrioid Carcinoma Is Associated with Poor Clinical Outcomes and High Tumor Mutation Burden

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.

Caveolin-1‘s dual impact on endometrioid endometrial carcinoma: a histopathological and immunohistochemical study

ABSTRACT The objectives of this study are to evaluate caveolin-1 expression in endometrioid endometrial cancer and its correlation with clinicopathological parameters. Forty-four cases of endometrioid endometrial carcinomas underwent radical hysterectomy. The archived paraffin sections that were stained for caveolin-1 by immunohistochemistry, caveolin-1 expression were detected in cancerous epithelial cells in 18.2% of the cases, and stromal caveolin-1 was detected in 65.9% of the cases. Caveolin-1 expression in the epithelium showed a significant positive association with the T stage and the FIGO stage. Positive caveolin-1 expression in epithelium has a direct, positive and significant relationship with invasion of other organs and a direct and significant relationship with the advanced FIGO stage. As for caveolin-1 expression in the stroma, it showed a significant negative inversely significant association with myometrial invasion. Also, there is a significant negative association between caveolin-1 expression in the epithelium and its expression in the stroma. We conclude that caveolin-1 expression strongly plays a critical role in endometrioid endometrial carcinoma as a tumor suppressor or promoter of invasion. In early lesions, high stromal levels appear to be protective against progression. While decreased stromal expression and increased epithelial expression were associated with aggressive tumors.

The DNA Damage Response (DDR) landscape of endometrial cancer defines discrete disease subtypes and reveals therapeutic opportunities.

Genome maintenance is an enabling characteristic that allows neoplastic cells to tolerate the inherent stresses of tumorigenesis and evade therapy-induced genotoxicity. Neoplastic cells also deploy many mis-expressed germ cell proteins termed Cancer Testes Antigens (CTAs) to promote genome maintenance and survival. Here, we present the first comprehensive characterization of the DNA Damage Response (DDR) and CTA transcriptional landscapes of endometrial cancer in relation to conventional histological and molecular subtypes. We show endometrial serous carcinoma (ESC), an aggressive endometrial cancer subtype, is defined by gene expression signatures comprising members of the Replication Fork Protection Complex (RFPC) and Fanconi Anemia (FA) pathway and CTAs with mitotic functions. DDR and CTA-based profiling also defines a subset of highly aggressive endometrioid endometrial carcinomas (EEC) with poor clinical outcomes that share similar profiles to ESC yet have distinct characteristics based on conventional histological and genomic features. Using an unbiased CRISPR-based genetic screen and a candidate gene approach, we confirm that DDR and CTA genes that constitute the ESC and related EEC gene signatures are required for proliferation and therapy-resistance of cultured endometrial cancer cells. Our study validates the use of DDR and CTA-based tumor classifiers and reveals new vulnerabilities of aggressive endometrial cancer where none currently exist.

Proteogenomic insights into early-onset endometrioid endometrial carcinoma: predictors for fertility-sparing therapy response.

Endometrial carcinoma remains a public health concern with a growing incidence, particularly in younger women. Preserving fertility is a crucial consideration in the management of early-onset endometrioid endometrial carcinoma (EEEC), particularly in patients under 40 who maintain both reproductive desire and capacity. To illuminate the molecular characteristics of EEEC, we undertook a large-scale multi-omics study of 215 patients with endometrial carcinoma, including 81 with EEEC. We reveal an unexpected association between exposome-related mutational signature and EEEC, characterized by specific CTNNB1 and SIGLEC10 hotspot mutations and disruption of downstream pathways. Interestingly, SIGLEC10Q144K mutation in EEECs resulted in aberrant SIGLEC-10 protein expression and promoted progestin resistance by interacting with estrogen receptor alpha. We also identified potential protein biomarkers for progestin response in fertility-sparing treatment for EEEC. Collectively, our study establishes a proteogenomic resource of EEECs, uncovering the interactions between exposome and genomic susceptibilities that contribute to the development of primary prevention and early detection strategies for EEECs.

Morules and β-catenin predict POLE mutation status in endometrial cancer: A pathway to more cost-effective diagnostic procedures.

The characterization of DNA polymerase epsilon (POLE) mutations has transformed the classification of endometrial endometrioid carcinomas (EECs), highlighting the need for efficient identification methods. This study aims to examine the relationship between distinct morphologic features-namely, squamous morules and squamous differentiation (SD), as well as β-catenin expression-and the POLE mutation status in endometrial cancer (EC). Our study included 35 POLE-mutated (POLEmut) EC cases and 395 non-POLEmut EEC cases. Notably, we observed no presence of morules in POLEmut cases, while SD was identified in 20% of instances. Conversely, morules and SD were identified in 12.7% and 26.1% of non-POLEmut EC cases, respectively, with morules consistently linked to a POLE wild-type status. The nuclear β-catenin expression is typically absent in tumors with wild-type POLE (wt-POLE) status. Our findings suggest that the presence of either morules or nuclear β-catenin expression in EEC could practically rule out the presence of POLE mutations. These morphologic and immunohistochemical features can be used as preliminary screening tools for POLE mutations, offering significant savings in time and resources and potentially enhancing clinical decision-making and patient management strategies. However, further validation in larger, multi-institutional studies is required to fully understand the implications of these findings on clinical practice.

Abstract IA022: Harnessing the unique biology of CD73 for improving endometrial cancer outcomes

Abstract Uncovering mechanisms that contribute to the unique pathobiology of endometrial cancer has the potential to reveal opportunities for improving outcomes. CD73, a cell surface 5’nucleotidase that generates adenosine, has emerged as an attractive therapeutic target; inhibiting CD73 therapeutically restores antitumor immune responses. While anti-CD73 agents appear promising for several cancer types, the biology of CD73 in endometrial cancer is proving to be complex and distinct from other solid tumors. Here, we present two unpublished studies of novel roles for CD73 that diverge from current paradigms. Critically, we show how the unique biology of CD73 in endometrial cancer can be leveraged to improve patient outcomes. We previously reported that although CD73 is upregulated in many tumors, supporting tumorigenesis, CD73 is downregulated in aggressive (grade 3 endometrioid and serous) endometrial carcinomas and its loss is associated with poor outcomes. First, we show through comprehensive immunohistochemistry (n=119) and TCGA computational analyses of microsatellite stable grade 2 endometrioid endometrial carcinomas with intact mismatch repair that loss of CD73, as opposed to its upregulation (as seen in other tumors), reprograms endometrial cancer cells to develop immunosuppressive features. CD73 cancer cell downregulation results in proinflammatory cytokine/chemokine (e.g., CXCL10, CXCL9, CCL8, IL11, IL32) upregulation. Consequently, to counterbalance the inflammatory environment, cancer cells upregulate immunosuppressive genes (e.g., PD-L1). Second, we reveal that CD73 critically restrains the oncogenic transcriptional activity of mutant β-catenin. Mutations in exon 3 of CTNNB1 (the gene that encodes β-catenin) occur in ~26% of low grade endometrioid endometrial carcinomas. CD73 sequesters exon 3 mutant β-catenin (β-cateninEX3) to the membrane, dampening its oncogenic transcriptional activity. A clinical challenge with β-cateninEX3 mutant endometrioid tumors is that half of these patients recur and will have poor outcomes. We show low CD73 expression in endometrioid tumors independently predicts disease recurrence and therefore CD73 may serve as a predictive biomarker where none currently exists. Moreover, we have identified that CD73 differentially controls different patient-specific β-cateninEX3 mutants. Understanding the unique mechanisms of CD73 signaling in endometrial cancer will reveal opportunities for precision medicine strategies. Our studies highlight the continued need and opportunities that exist from focused efforts elucidating the molecular mechanisms driving endometrial cancer. Citation Format: Jessica L. Bowser, Hannah N. Lee, Rebecca H. Hirsch, Xingyuan Zhang, Russell R. Broaddus, Katherine C. Kurnit, Suzanne M. Crumley, Sunthoshini Premsankar, Emily M. Rabjohns, Lilly F. Chiou, Cyrus Vaziri. Harnessing the unique biology of CD73 for improving endometrial cancer outcomes [abstract]. In: Proceedings of the AACR Special Conference on Endometrial Cancer: Transforming Care through Science; 2023 Nov 16-18; Boston, Massachusetts. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(5_Suppl):Abstract nr IA022.

Abstract B030: DNA methylation profiling identifies subset of low-grade endometrial neoplasms with poor response to progestin therapy

Abstract Purpose: We aimed to investigate the DNA methylation profile of low-grade endometrial neoplasms before and after progestin therapy. Methods: This is a retrospective cohort of patients with endometrial intraepithelial neoplasia/atypical hyperplasia (EIN/AH) and grade 1 endometrial endometrioid carcinoma (EEC) treated with progestin therapy. DNA was extracted from 24 formalin-fixed paraffin-embedded (FFPE) tumors before and 19 tumors after progestin therapy (median interval between specimens: 12.1 months). Methylation profiling was performed using the Illumina Infinium Methylation EPIC array. Laser-capture microdissection was used to enrich samples with low tumor content. Results: Twenty-four patients with a median age of 38 years were included. Majority of patients were nulligravid (58%), and self-identified as non-Hispanic (83%) and white (42%). Ten patients had a diagnosis of EIN/AH, while 14 were grade 1 EEC. Ten cases showed complete response, 7 partial responses, 8 showed no response between the pre- and post-treatment samples. Ten patients had regression of disease on follow-up, while 9 showed persistent tumor. In 5 patients, clinical outcome could not be assessed due to short time of exposure (&amp;lt;6 months). Unsupervised clustering based on top 3,000 differentially methylated sites (DMS) in 24 pre-treated tumors identified 2 different groups. Cluster 1 (n= 11) was composed of significantly older patients (p=0.047; median age: 39 vs 37 years) and more likely to have EEC on histologic examination (p=0.016; 100% vs 54%). Tumors in Cluster 1 were more likely to show absence of pathologic response following progestin therapy (p= 0.038; 55% vs 8%). Although no statistical significance was reached regarding clinical outcome (p=0.2), patients in Cluster 1 showed regression of disease in only 29% of cases (2/7), while in Cluster 2, 67% of patients showed regression of tumor (8/12). There was no difference regarding gravidity, race/ethnicity, body mass index, type of progestin, and follow-up time. KEGG pathways analysis revealed that the most significantly different pathways between the 2 clusters were: maturity onset diabetes of young, neuroactive ligand-receptor interaction, and signaling pathways regulating pluripotency of stem cells. Pairwise differential DNA methylation analysis between 15 pairs of pre- and post-treatment samples that passed quality control showed a hypermethylation effect of progestin therapy in the majority of DMS, including sites in open sea, northern and southern shores and shelves. Although there were sites in CpG islands with a hypermethylation pattern after treatment, progestin therapy had a predominantly hypomethylation effect on CpG islands. The gene set enrichment based on DMS showed significant change in genes mostly related to cell-cell adhesion following progestin therapy. Conclusion: DNA methylation profiling identifies a subset of EIN/AH and grade 1 EEC with poor response to progestin therapy. The methylation landscape of these low-grade neoplasms undergoes changes after progestin treatment. Citation Format: Lawrence H. Lin, Kyriaki Founta, Nyasha Chambwe, Deborah F. DeLair. DNA methylation profiling identifies subset of low-grade endometrial neoplasms with poor response to progestin therapy [abstract]. In: Proceedings of the AACR Special Conference on Endometrial Cancer: Transforming Care through Science; 2023 Nov 16-18; Boston, Massachusetts. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(5_Suppl):Abstract nr B030.

Abstract A018: A phase 2, open-label, single-arm, prospective, multicenter study of nab-sirolimus plus letrozole in advanced or recurrent endometrioid endometrial cancer

Abstract Introduction/Objective: This trial in progress is designed to evaluate the anti-tumor activity of nab-sirolimus in combination with letrozole in patients with advanced or recurrent endometrioid endometrial carcinoma (EEC). Despite recent pivotal data demonstrating improved outcomes with immunotherapy plus chemotherapy, regardless of mismatch repair status, alternative treatment options, particularly for advanced or recurrent EEC remain necessary. Dysregulation of mammalian target of rapamycin (mTOR) signaling is implicated in the pathology of EEC, in which &amp;gt;80% harbor PTEN or PI3K/AKT/mTOR pathway alterations. Moreover, crosstalk between mTOR and estrogen receptor signaling pathways is associated with endocrine resistance. GOG-3007 and other phase 2 studies have demonstrated that the combination of conventional mTOR inhibitors (mTORis) and endocrine therapy provides clinical benefit in patients with EC. nab-Sirolimus, a nanoparticle injectable form of mTORi, is approved in the USA for malignant perivascular epithelioid cell tumor. Preclinical data of nab-sirolimus demonstrated improved tumor accumulation, mTOR inhibition, and tumor growth suppression compared with conventional mTORis. We hypothesize that nab-sirolimus in combination with letrozole may produce synergistic antitumor activity in patients with recurrent EEC. Methods: In this phase 2, open-label, single-arm, multicenter study (NCT05997017), nab-sirolimus (100 mg/m2, intravenous, on days 1 and 8 of each 21-day cycle) and letrozole (2.5 mg, oral, daily) are administered to patients (~29 planned) with clinically confirmed, advanced, or recurrent EEC. Eligibility criteria include age ≥18 years, ≤1 prior chemo-based regimen, Eastern Cooperative Oncology Group performance status score 0 or 1, naïve to mTORi, and measurable disease (per Response Evaluation Criteria in Solid Tumors [RECIST] v1.1). The primary endpoint is best overall response rate by RECIST v1.1. Key secondary endpoints include duration of response, progression-free survival, overall survival, and safety. The relationship between biomarkers and response outcomes is an exploratory endpoint. Citation Format: Lauren E. Dockery, Anna Priebe, Linda Duska, Angela K. Green, Cara Mathews, Fernanda Musa, David O'Malley, Allison Puechl, Li Ding, Anita N. Schmid, Willis H. Navarro, Brian Slomovitz, Kathleen Moore. A phase 2, open-label, single-arm, prospective, multicenter study of nab-sirolimus plus letrozole in advanced or recurrent endometrioid endometrial cancer [abstract]. In: Proceedings of the AACR Special Conference on Endometrial Cancer: Transforming Care through Science; 2023 Nov 16-18; Boston, Massachusetts. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(5_Suppl):Abstract nr A018.

Abstract B015: A novel Cluster 3 Endometrial Cancer PDX model to test hormone therapy regimens

Abstract Endometrial cancer is the most commonly diagnosed gynecologic cancer and continues to rise in incidence and mortality rates worldwide. With the evaluation of large datasets including the TCGA, endometrial cancers have been subdivided into four different cluster groups based on molecular characteristics. The most common subtype of endometrial cancer is the Cluster 3 category, demarcated by the expression of estrogen receptors (ER) and progesterone receptors (PR) with the potential to respond to hormonal therapy. However, Cluster 3 tumors frequently lose hormone receptor expression over time, particularly PR, making them resistant to treatment. Although numerous cell line models exist to study this disease, there is a need for improved models to select best treatment options for the specific types of endometrial cancers. Here, we describe the development of an endometrial cancer patient derived xenograft (PDX), EC-PDX3. The initial tumor from which EC-PDX3 was derived was a low-grade endometrioid endometrial carcinoma that contained a low number of somatic copy number alterations. The tumor initially tested robustly positive for both ER and PR in the donor patient as well as in initial passages in athymic mice, making this model valuable for hormone therapy research. In these studies, EC-PDX3 cells were grown within immunodeficient NSG mice. We performed H&amp;E, ER and PR staining prior to experimentation and found that while ER remained highly positive, PR levels were significantly downregulated, indicating the development of a hormone resistant state similar to that occurring in patients over time. To determine if these cells respond to hormonal therapy and if PR expression could be induced, mice were initially treated with estradiol to enhance PR expression. Next, mice were further treated with progesterone or onapristone, an experimental progestin agonist/antagonist with previously reported encouraging activity in advanced endometrial cancer in phase I and II trials. Tumors were measured weekly to determine hormone effects on cancer growth. Mice treated with estradiol alone showed substantially larger tumor growth as compared to the estradiol + progesterone and estradiol + onapristone treatment groups, indicating that hormone sensitivity was likely re-instated. RNA sequencing using Ishikawa cells in culture revealed the transcriptional effects of estradiol, progesterone and onapristone which complement the data obtained from EC-PDX3 bearing mice treated similarly. These studies identify interesting growth inhibitory effects of onapristone in endometrial cancer cells primed with estradiol including the significant induction of the cell cycle regulators such as p21 and genes involved in apoptosis. In addition, EC-PDX3 provides a model to assess hormonal therapy in Cluster 3 tumors that initially respond but develop resistance to treatment over time. Citation Format: Kimberly K. Leslie, Lane E. Smith, Jamie Padilla, Adrian Quintana. A novel Cluster 3 Endometrial Cancer PDX model to test hormone therapy regimens [abstract]. In: Proceedings of the AACR Special Conference on Endometrial Cancer: Transforming Care through Science; 2023 Nov 16-18; Boston, Massachusetts. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(5_Suppl):Abstract nr B015.

Integration of the Molecular Classification of Endometrial Carcinoma to Select Patients for Fertility Sparing Strategies.

Fertility-sparing treatment (FST) for endometrial carcinoma (EC) is an option for a subgroup of young women with low-risk disease. The low-risk group comprises patients with endometrioid EC stage IA, grade 1, with or without focal lymphovascular invasion. In the era of molecular subtyping, treatment de-escalation for some EC subtypes is recommended. Recommendations for fertility-preserving treatments were developed regardless of the molecular classification of EC. However, few studies have focused on this topic. In this review, we summarize the actual data available in the literature and discuss the impact of some molecular subtypes of FST.

Clinical Significance of Tumor Immune Microenvironment in Endometrial Endometrioid Carcinoma, Grade 1 With DNA Mismatch Repair Protein Loss.

The administration of immune checkpoint inhibitors (ICIs) is increasing in endometrial cancer, especially in the mismatch repair (MMR)-deficient group. To prevent unnecessary immune-related adverse events, ICIs need to be administered to more appropriate patients. The tumor immune microenvironment has been reported to be a predictive marker of the efficacy of ICI therapies. This study evaluated CD8, FoxP3, CD68, PD-L1, and β-catenin expression in endometrial endometrioid carcinoma, grade 1 (G1) with DNA mismatch repair protein loss (MMR loss), and their association with clinicopathological features. We retrospectively analyzed tumor samples from 107 patients with endometrial endometrioid carcinoma, G1 (MMR-deficient group: n=67; MMR-proficient group: n=40). Overall, 47 cases of MLH1/PMS2 loss and 20 cases of MSH2/MSH6 loss were observed. The patients with low intraepithelial CD8 expression significantly more frequently exhibited deep myometrial invasion, and the elderly group (≥60 y) significantly more frequently showed low stromal CD8 expression. In addition, FoxP3-positive cell count and FoxP3/CD8+ ratio were significantly correlated with the International Federation of Obstetrics and Gynecology 2023 stage and lymph node metastasis. In the Kaplan-Meier analysis, the patients with low intraepithelial or stromal CD8 expression had shorter progression-free survival (PFS) than those with high intraepithelial or stromal CD8 expression, albeit not significantly. We clarified that the tumor immune microenvironment had an impact on clinicopathological features within the group with MMR loss, which is the main target for ICIs, limited to endometrioid carcinoma, G1. Further studies are needed, including on patients administered ICIs.

The interplay between the epithelial permeability barrier, cell migration and mitochondrial metabolism of growth factors and their inhibitors in a human endometrial carcinoma cell line

ABSTRACT It is known that there are abnormalities of tight junction functions, cell migration and mitochondrial metabolism in human endometriosis and endometrial carcinoma. In this study, we investigated the effects of growth factors and their inhibitors on the epithelial permeability barrier, cell migration and mitochondrial metabolism in 2D and 2.5D cultures of human endometrioid endometrial carcinoma Sawano cells. We also investigated the changes of bicellular and tricellular tight junction molecules and ciliogenesis induced by these inhibitors. The growth factors TGF-β and EGF affected the epithelial permeability barrier, cell migration and expression of bicellular and tricellular tight junction molecules in 2D and 2.5D cultures of Sawano cells. EW-7197 (a TGF-β receptor inhibitor), AG1478 (an EGFR inhibitor) and SP600125 (a JNK inhibitor) affected the epithelial permeability barrier, cell migration and mitochondrial metabolism and prevented the changes induced by TGF-β and EGF in 2D and 2.5D cultures. EW-7197 and AG1478 induced ciliogenesis in 2.5D cultures. In conclusion, TGF-β and EGF promoted the malignancy of endometrial cancer via interplay among the epithelial permeability barrier, cell migration and mitochondrial metabolism. EW-7197 and AG1478 may be useful as novel therapeutic treatments options for endometrial cancer.

Abnormal p53 expression is associated with poor outcomes in grade I or II, stage I, endometrioid carcinoma: a retrospective single-institute study.

The Cancer Genome Atlas study revealed an association between copy-number high (p53 abnormal) genetic mutation and poor prognosis in endometrial cancer in 2013. This retrospective study investigated outcomes in patients with abnormal p53 expression and stage I, low-grade endometrial endometrioid carcinoma (EEC). We enrolled women with stage I, grade 1 or 2 EEC who received comprehensive staging and adjuvant therapy between January 2019 and December 2022 at MacKay Memorial Hospital, Taipei, Taiwan. Pathologists interpreted immunohistochemistry stains of cancerous tissues to detect p53 mutation. We compared recurrence, survival, progression-free survival, and overall survival between p53 abnormal and p53 normal groups. Of the 115 patients included, 26 had pathologically confirmed abnormal p53 expression. Of these 26 patients, five (19.2%) experienced recurrence, and two died due to disease progression. By contrast, no patients in the normal p53 group experienced disease recurrence or died due to disease progression. Significant intergroup differences were discovered in recurrent disease status (19.4% vs. 0%, p<0.001), mortality (7.7% vs. 0%, p<0.001), and progression-free survival (p<0.001). The overall survival (p=0.055) also showed powerful worse trend. For patients with stage I, low-grade EEC, abnormal p53 expression may be used as an indicator of poor prognosis. Therefore, we suggest considering aggressive adjuvant therapies for these patients.

Next-generation sequencing and immunohistochemistry approaches for microsatellite instability detection in endometrial cancer.

The purpose was to determine the effectiveness of immunohistochemical observation, a quick and easy method for determining Microsatellite instability MSI and/or other types of endometrial cancer (EC) based on modern classification. As molecular study takes more cost we want to compare both methods and show the possibility of doing IHC instead of molecular study. This study was designed to establish a small gene panel of Next Generation Sequencing (NGS) of endometrial cancer patients targeting 4 mismatch repair genes; MSH6, MSH2, MLH1 and PMS2. Using the DNBSEQ-G400 Platform, the Human Core Exome kit and Python software for analysis were used. At the same time, the Dako kit was used to perform IHC for six primary antibodies used to detect each of MSH6, MSH2, MLH and PMS2. The primary antibodies were applied on 5 µm formalin-fixed paraffin-embedded (FFPE). Results showed that histopathological examinations of all patients were at stage I endometrioid endometrial carcinoma. The FIGO classifications were Ia and Ib. Microsatellite instability (MIS) was observed through the IHC study. The molecular studies detected several polymorphisms that have clinical significance and some of them have conflicting interpretations. In conclusion, we considered that a simple immunoreaction staining procedure can be used as an alternative method for MSI phenotype detection rather than any type of more expensive and complex method of NGS.

Molecular landscape of ERBB2/HER2 gene amplification among patients with gynecologic malignancies; clinical implications and future directions

ObjectiveInvestigate the prevalence of ERBB2/HER2 gene amplification among patients with gynecologic malignancies. MethodsThe American Association of Cancer Research (AACR) Genomics Evidence of Neoplasia Information Exchange (GENIE) (version 13.1) database was accessed and patients with endometrial, ovarian, and cervical cancer were identified. Patients with available data on the presence of copy-number gene alterations were selected for further analysis. Incidence of ERBB2 amplification following stratification by tumor site and histology was evaluated. Data from the OncoKB database, as provided by cBioPortal, was utilized to determine presence of pathogenic genomic alterations. ResultsA total of 6961 patients who met the inclusion criteria were identified: 49.1% with ovarian cancer, 45.2% with endometrial cancer and 5.7% with cervical cancer respectively. Overall incidence of ERBB2 amplification was 3.8%. Highest incidence of ERBB2 amplification was observed among patients with mucinous ovarian (14.4%), uterine serous (13.2%), uterine clear cell (9.4%), and uterine carcinosarcoma (7.9%). ERBB2 amplification was rare among patients with TP53 wild-type endometrioid endometrial cancer (0.4%). High incidence of mutations in genes of the PI3K pathway was observed among patients with ERBB2 amplified tumors. ConclusionERBB2 amplification is frequently encountered among patients with uterine serous carcinoma, and mucinous ovarian carcinoma. In addition, a high incidence was also observed among those with uterine clear cell carcinoma, and uterine carcinosarcoma. For patients with endometrioid endometrial carcinoma, incidence of ERBB2 amplification is low, especially in the absence of TP53 mutations.