High-grade Endometrioid Research Articles

Ovarian carcinosarcoma is highly aggressive compared to other ovarian cancer histotypes

BackgroundOvarian carcinosarcoma (OCS) is an unusual ovarian cancer type characterized by distinct carcinomatous and sarcomatous components. OCS has been excluded from many of the pan-histotype studies of ovarian carcinoma, limiting our understanding of its behavior.MethodsWe performed a multi-cohort cross-sectional study of characteristics and outcomes in ovarian cancer patients from Scotland (n=2082) and the Surveillance, Epidemiology and End Results Program (SEER, n=44946) diagnosed with OCS or one of the other major histotypes: high grade serous (HGSOC), endometrioid (EnOC), clear cell (CCOC), mucinous (MOC) or low grade serous ovarian carcinoma (LGSOC). Differences in overall survival were quantified using Cox regression models to calculate hazard ratios (HR).ResultsAcross both cohorts, OCS patients were significantly older at diagnosis compared to all other histotypes (median age at diagnosis 69 and 67 in Scottish and SEER cohorts) and demonstrated the shortest survival time upon univariable analysis. Within the Scottish cohort, 59.3% and 16.9% of OCS patients presented with FIGO stage III and IV disease, respectively; this was significantly higher than in EnOC, CCOC or MOC (P<0.0001 for all), but lower than in HGSOC (P=0.004). Multivariable analysis accounting for other prognostic factors identified OCS as independently associated with significantly shorter survival time compared to HGSOC, EnOC, LGSOC and MOC in both the Scottish (multivariable HR vs OCS: HGSOC 0.45, EnOC 0.39, LGSOC 0.26, MOC 0.43) and SEER cohorts (multivariable HR vs OCS: HGSOC 0.59, EnOC 0.34, LGSOC 0.30, MOC 0.81). Within the SEER cohort, OCS also demonstrated shorter survival compared to CCOC (multivariable HR 0.63, 95% CI 0.58-0.68), but this was not replicated within the Scottish cohort (multivariable HR for CCOC: 1.05, 95% CI 0.74-1.51). Within early-stage disease specifically (FIGO I-II or SEER localized stage), OCS was associated with the poorest survival of all histotypes across both cohorts. In the context of late-stage disease (FIGO III-IV or SEER distant stage), OCS, MOC and CCOC represented the histotypes with poorest survival.ConclusionOCS is a unique ovarian cancer type that affects older women and is associated with exceptionally poor outcome, even when diagnosed at earlier stage. New therapeutic options are urgently required to improve outcomes.

Abstract IA009: Racial disparities in high grade endometrial cancers

Abstract Endometrial cancer (EC) is the most common gynecological cancer in the United States, with approximately 66,200 cases diagnosed annually. Incidence rates have been increasing over the past two decades, especially in non-white and younger populations. Additionally, population-based studies have shown that the increases are greatest among the more aggressive histologic subtypes. In unadjusted analyses, incidence rates are highest among non-Hispanic white women (NHW); however, when the greater prevalence of hysterectomies in non-Hispanic black women (NHB) is accounted for, the incidence among NHB women exceeds that of other racial and ethnic groups. In addition, survival after an EC diagnosis is significantly lower for NHB women at every stage of diagnosis, and for all histologic subtypes. EC is currently the 6th leading cause of cancer-related deaths among women but will likely overtake ovarian cancer (the 5th leading cause) before the end of the decade—it has already done so for NHB women. Factors influencing survival exist across the cancer care spectrum, starting at diagnosis and continuing through treatment and beyond. A portion of the differences in EC survival can be explained by the histologic subtype of the tumor. Low grade endometrioid ECs are the most common histologic type and tend to have a good prognosis. High grade tumors, such as serous cancers, are more common among NHB women and have poorer prognosis. A better understanding of the molecular characteristics of these more aggressive tumors is warranted, as they are increasing in incidence and cause a disproportionate amount of morbidity and mortality. To date, most studies that have included molecular profiling do not have large enough numbers or participants from diverse populations to examine whether mutations that may be clinically significant differ by race and ethnicity in high grade endometrial cancers. In a population of women with high grade EC (endometrioid, serous, clear cell, mixed) identified from two academic hospitals in Detroit, Michigan, we performed whole exome sequencing on tumor and normal tissue from 285 women. We hypothesized that somatic mutations in specific genes may vary by race and ultimately contribute to the survival disparity consistently identified in population-based studies. We report findings from the two most common high grade histologic subtypes, endometrioid (n=51 NHB, n=60 NHW) and serous (n=85 NHB, n=37 NHW). Established and emerging therapeutic targets were selected as a priori for the initial analysis. Tumor mutational burden (TMB), microsatellite instability status (MSI), mutations in genes in the PIK3 pathway, POLE, ARID1A and p53 were all examined. Findings highlight the need to consider histologic subtype in conjunction with race and ethnicity, as failure to do so may erroneously confound the estimates. Larger studies in diverse populations will be critical to disentangle the contribution of ancestry, histology and somatic mutations to the survival disparities seen after an EC diagnosis. Citation Format: Michele L. Cote. Racial disparities in high grade endometrial cancers [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 IA009.

Drug-Resistant Epithelial Ovarian Cancer: Current and Future Perspectives.

Epithelial ovarian cancer (EOC) is a complex disease with diverse histological subtypes, which, based on the aggressiveness and course of disease progression, have recently been broadly grouped into type I (low-grade serous, endometrioid, clear cell, and mucinous) and type II (high-grade serous, high-grade endometrioid, and undifferentiated carcinomas) categories. Despite substantial differences in pathogenesis, genetics, prognosis, and treatment response, clinical diagnosis and management of EOC remain similar across the subtypes. Debulking surgery combined with platinum-taxol-based chemotherapy serves as the initial treatment for High Grade Serous Ovarian Carcinoma (HGSOC), the most prevalent one, and for other subtypes, but most patients exhibit intrinsic or acquired resistance and recur in short duration. Targeted therapies, such as anti-angiogenics (e.g., bevacizumab) and PARP inhibitors (for BRCA-mutated cancers), offer some success, but therapy resistance, through various mechanisms, poses a significant challenge. This comprehensive chapter delves into emerging strategies to address these challenges, highlighting factors like aberrant miRNAs, metabolism, apoptosis evasion, cancer stem cells, and autophagy, which play pivotal roles in mediating resistance and disease relapse in EOC. Beyond standard treatments, the focus of this study extends to alternate targeted agents, including immunotherapies like checkpoint inhibitors, CAR T cells, and vaccines, as well as inhibitors targeting key oncogenic pathways in EOC. Additionally, this chapter covers disease classification, diagnosis, resistance pathways, standard treatments, and clinical data on various emerging approaches, and advocates for a nuanced and personalized approach tailored to individual subtypes and resistance mechanisms, aiming to enhance therapeutic outcomes across the spectrum of EOC subtypes.

Causality and functional relevance of BRCA1 and BRCA2 pathogenic variants in non-high-grade serous ovarian carcinomas.

The identification of causal BRCA1/2 pathogenic variants (PVs) in epithelial ovarian carcinoma (EOC) aids the selection of patients for genetic counselling and treatment decision-making. Current recommendations therefore stress sequencing of all EOCs, regardless of histotype. Although it is recognised that BRCA1/2 PVs cluster in high-grade serous ovarian carcinomas (HGSOC), this view is largely unsubstantiated by detailed analysis. Here, we aimed to analyse the results of BRCA1/2 tumour sequencing in a centrally revised, consecutive, prospective series including all EOC histotypes. Sequencing of n = 946 EOCs revealed BRCA1/2 PVs in 125 samples (13%), only eight of which were found in non-HGSOC histotypes. Specifically, BRCA1/2 PVs were identified in high-grade endometrioid (3/20; 15%), low-grade endometrioid (1/40; 2.5%), low-grade serous (3/67; 4.5%), and clear cell (1/64; 1.6%) EOCs. No PVs were identified in any mucinous ovarian carcinomas tested. By re-evaluation and using loss of heterozygosity and homologous recombination deficiency analyses, we then assessed: (1) whether the eight 'anomalous' cases were potentially histologically misclassified and (2) whether the identified variants were likely causal in carcinogenesis. The first 'anomalous' non-HGSOC with a BRCA1/2 PV proved to be a misdiagnosed HGSOC. Next, germline BRCA2 variants, found in two p53-abnormal high-grade endometrioid tumours, showed substantial evidence supporting causality. One additional, likely causal variant, found in a p53-wildtype low-grade serous ovarian carcinoma, was of somatic origin. The remaining cases showed retention of the BRCA1/2 wildtype allele, suggestive of non-causal secondary passenger variants. We conclude that likely causal BRCA1/2 variants are present in high-grade endometrioid tumours but are absent from the other EOC histotypes tested. Although the findings require validation, these results seem to justify a transition from universal to histotype-directed sequencing. Furthermore, in-depth functional analysis of tumours harbouring BRCA1/2 variants combined with detailed revision of cancer histotypes can serve as a model in other BRCA1/2-related cancers. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

A retrospective study of consistency between immunohistochemistry and polymerase chain reaction of microsatellite instability in endometrial cancer.

Identification of endometrial cancers (EC) with mismatch repair deficiency (dMMR) or microsatellite instability-high (MSI-H) is essential for Lynch syndrome screening and treatment stratification. We aimed to assess the utility of immunohistochemistry (IHC) staining for MMR protein expression and polymerase chain reaction (PCR)-based MSI assays in EC and the correlation between MMR/MSI status and various clinicopathological parameters. We reviewed the clinical and pathological information of 333 patients with EC. MMR protein expression was assessed as retained or lost to determine MMR status by IHC staining, and MSI status was identified by PCR capillary electrophoresis (PCR-CE) testing with a National Cancer Institute (NCI) panel. The correlation of MMR/MSI status with clinicopathological features was determined by statistical analysis. Discrepant results were further analyzed using an alternative PCR-CE MSI (Promega panel) method, MLH1 promoter methylation assays, and next-generation sequencing (NGS). Among the EC patients, the overall percentage of dMMR was 25.2%, and the overall percentage of MSI-H was 24%. Among the dMMR patients, 50 (59.5%) showed loss of MLH1 and PMS2 expression, 19 (22.6%) loss of MSH2 and MSH6 expression, and seven (8.3%) and eight (9.5%) loss of PMS2 and MSH6 expression, respectively. The dMMR subgroup was significantly younger than the pMMR subgroup, especially for <60-years-old patients (p=0.038). In addition, we identified a strong correlation between MMR/MSI status and high-grade endometrioid or nonendometrioid components (p=0.004 or p=0.003). IHC staining and PCR-CE assay results showed a high level of overall concordance (98.8%, Cohen's κ=0.98). Four patients were found to have dMRR/MSS in both examinations. We reanalyzed them with additional methods. One case showed MLH1 promotor methylation, and the other three cases harbored MSH6 germline pathogenic variations. One of the cases with MSH6 deficiency was reanalyzed as MSI-H by alternative PCR-CE assay or NGS testing. This study indicates that the combined use of MMR-IHC and PCR-CE MSI analyses may effectively avoid misdiagnoses of EC patients with dMMR/MSI-H. However, use of PCR-CE alone to evaluate MMR/MSI status may lead to missed diagnosis, especially for EC patients with MSH6 deficiency and presenting MSS.

Participance in time of the different stages of medical help is the necessary factor for the success of realization of practical medical activity (with the description of own observations of ovarian cancer clinical case and its using at classes in State l

Ovarian cancer is a second by the rate gynecological malignant disorder in developed countries and has one of the worst prognosis and mortality rate. In comparison to other gynecological malignant disorders (cervical, uterіne, vaginal, vulvar), patients with ovarian cancer suffer from the biggest mortality rate. Because of the absence of the early detection methods patients most common are identified at developed stage (III or IV by FIGO), thus with limited possibilities for treatment. Epithelial ovarian cancer is the most common type of ovarian cancer with 90 % of all reported cases. This cancer is divided in five histotypes: highgrade serous, low-grade serous, mucinous, endometrioid and clear-cell. Histotypes are different in morphology of tumor cells, clinical manifestations intensity, systemic effect and response to treatment. General clinical hardship of ovarian cancer detection on early stages due to the lack of definite semiotic picture produces the big role of primary care specialists for the systemic evaluation of the female health state with consideration of the “small signs” of the disorder, which progress constantly and with time will be transformed to obvious morphological oncomanifestations. Article contains the results of own clinical observations of the features of ovarian cancer. We consider this description as demonstrative for the analysis at practical classes in State language and in English.

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

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

Investigating the suitability of in vitro cell lines as models for the major subtypes of epithelial ovarian cancer.

Epithelial ovarian cancer (EOC) is the most fatal gynaecological malignancy, accounting for over 200,000 deaths worldwide per year. EOC is a highly heterogeneous disease, classified into five major histological subtypes-high-grade serous (HGSOC), clear cell (CCOC), endometrioid (ENOC), mucinous (MOC) and low-grade serous (LGSOC) ovarian carcinomas. Classification of EOCs is clinically beneficial, as the various subtypes respond differently to chemotherapy and have distinct prognoses. Cell lines are often used as in vitro models for cancer, allowing researchers to explore pathophysiology in a relatively cheap and easy to manipulate system. However, most studies that make use of EOC cell lines fail to recognize the importance of subtype. Furthermore, the similarity of cell lines to their cognate primary tumors is often ignored. Identification of cell lines with high molecular similarity to primary tumors is needed in order to better guide pre-clinical EOC research and to improve development of targeted therapeutics and diagnostics for each distinctive subtype. This study aims to generate a reference dataset of cell lines representative of the major EOC subtypes. We found that non-negative matrix factorization (NMF) optimally clustered fifty-six cell lines into five groups, putatively corresponding to each of the five EOC subtypes. These clusters validated previous histological groupings, while also classifying other previously unannotated cell lines. We analysed the mutational and copy number landscapes of these lines to investigate whether they harboured the characteristic genomic alterations of each subtype. Finally we compared the gene expression profiles of cell lines with 93 primary tumor samples stratified by subtype, to identify lines with the highest molecular similarity to HGSOC, CCOC, ENOC, and MOC. In summary, we examined the molecular features of both EOC cell lines and primary tumors of multiple subtypes. We recommend a reference set of cell lines most suited to represent four different subtypes of EOC for both in silico and in vitro studies. We also identify lines displaying poor overall molecular similarity to EOC tumors, which we argue should be avoided in pre-clinical studies. Ultimately, our work emphasizes the importance of choosing suitable cell line models to maximise clinical relevance of experiments.

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

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

Abstract 3065: Establishment and characterization of a platform of endometrial cancer organoids

Abstract Background: Endometrial cancer is the most commonly diagnosed gynecologic cancer in the US; the incidence is rising, and survival rates for this cancer are decreasing. There is a paucity of effective treatment for recurrent endometrial cancer, especially high grade endometrial cancers (HGEC) which include serous, carcinosarcoma, endometrioid, and clear cell histologies. Models that mimic the clinical and molecular characteristics of HGEC are lacking. To support the development of next generation therapeutics for endometrial cancer, we report on the establishment of 3D endometrial patient-derived organoids (PDOs) from HGEC. Methods: 26 Tumors from 21 different patients with HGEC (Serous, Carcinosarcoma, Clear Cell and High-grade Endometrioid subtypes) who underwent surgical resection (n= 13), biopsy (n = 7), paracentesis (n = 3) or thoracentesis (n = 3) were passaged as 3D organoid cultures in Matrigel in an optimized media. Robust models (defined by average days to passage &amp;lt;14 days) were viably banked. 3 frozen models were also thawed and re-cultured to assess the viability post freezing. PDOs were collected for H&amp;E staining and their histology was compared to the original diagnosis. DNA replication rate and the effect of replication stress on organoid growth were assessed by the DNA Fiber Assay and immunofluorescence (IF). Finally, an established clear cell endometrial cancer organoid model was engrafted in mice to generate a Patient-Derived Xenograft (PDX) model. Results: Endometrial PDOs were successfully developed from 19 of 26 original samples for an overall success rate of 73.1%. Successful PDOs were developed from multiple histologies, including 8 carcinosarcoma, 6 uterine serous, 2 endometrioid, 2 clear cell and 1 mixed uterine serous and endometrioid. Though biopsy samples had initially fewer viable cells, our overall success rate was similar at 85.7% compared to 84.6% for surgical resections and higher than 66.7% for paracenteses. Samples obtained via thoracentesis did not form PDOs. Endometrial PDOs were histologically validated to match the primary patient tumor. Freeze thawing had no effect on morphology and growth characteristics. DNA fiber assays could be successfully conducted in PDOs, with a reduction in replication rate observed in PDO models treated with ATR or WEE1 inhibitors, with concurrent increase in y-H2AX and decrease in pRPA2 observed by IF. We also successfully generated a validated PDX model from organoids. Studies to determine molecular fidelity between the original patient tumor and established organoids are ongoing. Conclusions: We describe the successful establishment of 19 endometrial PDO models which retain original tumor morphology and demonstrate sensitivity to drug-induced DNA damage. 3D endometrial organoids can therefore be used for further target discovery and validation as well as biomarker studies to advance targeted therapies for high-grade endometrial cancer. Citation Format: Aisha L. Saldanha, Ha V. Vo, Kevin Vasquez, Kenneth Ngo, Shrabasti Roychoudhury, Carina Feeney, Courtney H. Qi, Swati Narayan, Jennifer D. Curtis, Prafulla C. Gokhale, Dipanjan Chowdhury, Cloud P. Paweletz, Marisa R. Nucci, Ursula A. Matulonis, Elena Ivanova, Joyce F. Liu. Establishment and characterization of a platform of endometrial cancer organoids [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3065.

Clinical implications of tumor-based next-generation sequencing in ovarian cancer.

5545 Background: Epithelial ovarian cancer is genetically heterogeneous, both among and within histologic subtypes. Advances in next-generation sequencing have made it feasible to ascertain the somatic genetic signature of each patient, however, critical analysis of population-level sequencing results is required to maximize the potential of this technology. Here, we aimed to assess the clinical relevance of tumor-based next-generation sequencing (tbNGS) in a large cohort of patients with high-grade epithelial ovarian cancer. Methods: Our study population comprised patients with high-grade serous (n = 972), clear cell (n = 33), endometrioid (n = 28), mucinous (n = 4), and mixed (n = 34) or unspecified (n = 21) epithelial ovarian carcinoma diagnosed between April 2013 and September 2021. tbNGS results were identified within the electronic medical record using optical character recognition and natural language processing. Genetic, clinical, and demographic information was collected for patients who had undergone tbNGS. Progression-free survival (PFS) and overall survival (OS) were calculated from date of first treatment to date of first recurrence and date of death, respectively. Data were analyzed using descriptive statistics, univariate and multivariate Cox regression models, and clustering analyses. Results: Of 1092 patients in the described population, 409 (37.5%) had tbNGS results identified. Nearly all (96.1%) revealed one or more genetic aberrations. Most patients (74.6%) had an actionable mutation, defined as relaying eligibility for a targeted treatment or clinical trial. The most frequent alterations were TP53, PIK3CA, and NF1 mutations; and CCNE1 amplification. Ten different targeted institutional and commercial panels were employed, covering a range of 35 to 600+ gene loci. The median time from diagnosis to testing was 14.5 months, likely corresponding to time of recurrence. Though no standalone alterations were significantly related to survival, multivariate and clustering analyses identified several genetic patterns which corresponded to patient outcomes. Mutation of BRAF, PIK3R1, NOTCH3, MET, and/or ATR was correlated with shorter PFS (HR 1.84, p = 0.001); mutation of ATM, RB1, CDKN2A, FGFR1, and/or FGFR2 was associated with improved PFS (HR 0.64, p = 0.04), as was mutation of NBN and/or ATRX (HR 0.54, p &lt; 0.05). MYC, NOTCH3, and/or CREBBP mutations were significantly correlated with worse OS (HR 1.95, p = 0.02). In our population, 40 patients (9.78%) were enrolled in genotypically-relevant clinical trials. Conclusions: tbNGS is prevalent at our institution, and often yields actionable information. We identified several mutational patterns that correlate to patient survival. Detailed analysis of population-level tumor genomics may help to identify therapeutic targets and guide development of clinical decision support tools.

CTNNB1 -mutated High-grade Endometrioid Carcinoma With Extensive Squamous and Shadow Cell Differentiation Can Mimic Pilomatrix Carcinoma.

CTNNB1 -mutated High-grade Endometrioid Carcinoma With Extensive Squamous and Shadow Cell Differentiation Can Mimic Pilomatrix Carcinoma.

Genomic and TCR profiling data reveal the distinct molecular traits in epithelial ovarian cancer histotypes.

Epithelial ovarian cancer (EOC) is classified into five major histotypes: high-grade serous (HGSOC), low-grade serous (LGSOC), clear cell (CCOC), endometrioid (ENOC), and mucinous (MOC). However, the landscape of molecular and immunological alterations in these histotypes, especially LGSOC, CCOC, ENOC, and MOC, is largely uncharacterized. We collected 101 treatment-naive EOC patients. The resected tumor tissues and paired preoperative peripheral blood samples were collected and subjected to target sequencing of 1021 cancer-associated genes and T cell repertoire sequencing. Distinct characteristics of mutations were identified among the five histotypes. Furthermore, tumor mutation burden (TMB) was found to be higher in CCOC and ENOC, but lower in LGSOC and HGSOC. Alterations associated with DNA damage repair (DDR) pathways and homologous recombination deficiencies (HRD) were prevalent in five histotypes. CCOC demonstrated increased level of T cell clonality compared with HSGOC. Interestingly, the proportion of the 100 most common T cell clones was associated with TMB and tumor neoantigen burden in CCOC, highlighting more sensitive anti-tumor responses in this histotype, which was also evidenced by the enhanced convergent recombination of T cell clones. These findings shed light on the molecular traits of genomic alteration and T cell repertoire in the five major EOC histotypes and may help optimize clinical management of EOC with different histotypes.

Expression of epigenetic pathway related genes in association with PD-L1, ER/PgR and MLH1 in endometrial carcinoma

The distribution of Endometrial Cancer (EC)-related deaths is uneven among the morphologic subtypes of EC. Serous Cancer (SC) makes 10% of all EC and accounts for 40% of EC-related deaths. We investigated expression of selected genes involved in epigenetic pathways by immunohistochemistry in a cohort of 106 EC patients and analyzed mRNA-based expression levels for the same set of genes in EC samples from The Cancer Genome Atlas (TCGA) dataset. A tissue microarray was constructed using low-grade (n = 30) and high-grade (n = 28) endometrioid, serous (n = 31) and clear cell carcinoma (n = 17) samples. Epigenetic marker levels were associated with PD-L1, ER/PgR, and MLH1 expression. Epigenetic markers were evaluated by H-score and PD-L1 expression was recorded by using Combined Positive Score. Results were correlated with disease stage and survival outcome. BRD4, KAT6a and HDAC9 levels were higher in SC compared to other histologic subtypes (p<0.001–0.038). After adjusting for multiple comparisons, DNMT3b expression was higher in SC compared to endometrioid-type but not between SC and CCC. The expression levels of BRD4 (p = 0.021) and KAT6a (p = 0.0027) were positively associated with PD-L abundance, while PgR (p = 0.029) and PD-L1 expression were negatively associated. In addition, BRD4 expression was low in specimens with loss of MLH1 expression (p = 0.02). More importantly, BRD4 abundance had a negative impact on disease outcome (p = 0.02). Transcriptionally, BRD4, KAT6a and DNMT3b expression levels were higher in SC in TCGA dataset. The median PD-L1 expression was marginally associated with BRD4, a transcriptional activator of CD274/PD-L1 (p = 0.069) and positively with KAT6a (p = 0.0095). In conclusion, the protein expression levels of epigenetic markers involved in cancer pathogenesis are increased by immunohistochemistry in SC. PD-L1 levels are associated with BRD4 and KAT6a in EC samples. A combination therapy with BRD4/PD-L1 or KAT6a/PD-L1 inhibitors might have a potential use in EC, in particular serous-type carcinoma.

Identifying causality, genetic correlation, priority and pathways of large-scale complex exposures of breast and ovarian cancers.

Genetic correlations, causalities and pathways between large-scale complex exposures and ovarian and breast cancers need systematic exploration. Mendelian randomisation (MR) and genetic correlation (GC) were used to identify causal biomarkers from 95 cancer-related exposures for risk of breast cancer [BC: oestrogen receptor-positive (ER + BC) and oestrogen receptor-negative (ER - BC) subtypes] and ovarian cancer [OC: high-grade serous (HGSOC), low-grade serous, invasive mucinous (IMOC), endometrioid (EOC) and clear cell (CCOC) subtypes]. Of 31 identified robust risk factors, 16 were new causal biomarkers for BC and OC. Body mass index (BMI), body fat mass (BFM), comparative body size at age 10 (CBS-10), waist circumference (WC) and education attainment were shared risk factors for overall BC and OC. Childhood obesity, BMI, CBS-10, WC, schizophrenia and age at menopause were significantly associated with ER + BC and ER - BC. Omega-6:omega-3 fatty acids, body fat-free mass and basal metabolic rate were positively associated with CCOC and EOC; BFM, linoleic acid, omega-6 fatty acids, CBS-10 and birth weight were significantly associated with IMOC; and body fat percentage, BFM and adiponectin were significantly associated with HGSOC. Both GC and MR identified 13 shared factors. Factors were stratified into five priority levels, and visual causal networks were constructed for future interventions. With analysis of large-scale exposures for breast and ovarian cancers, causalities, genetic correlations, shared or specific factors, risk factor priority and causal pathways and networks were identified.

Distinct transcriptional programs stratify ovarian cancer cell lines into the five major histological subtypes

BackgroundEpithelial ovarian cancer (OC) is a heterogenous disease consisting of five major histologically distinct subtypes: high-grade serous (HGSOC), low-grade serous (LGSOC), endometrioid (ENOC), clear cell (CCOC) and mucinous (MOC). Although HGSOC is the most prevalent subtype, representing 70–80% of cases, a 2013 landmark study by Domcke et al. found that the most frequently used OC cell lines are not molecularly representative of this subtype. This raises the question, if not HGSOC, from which subtype do these cell lines derive? Indeed, non-HGSOC subtypes often respond poorly to chemotherapy; therefore, representative models are imperative for developing new targeted therapeutics.MethodsNon-negative matrix factorisation (NMF) was applied to transcriptomic data from 44 OC cell lines in the Cancer Cell Line Encyclopedia, assessing the quality of clustering into 2–10 groups. Epithelial OC subtypes were assigned to cell lines optimally clustered into five transcriptionally distinct classes, confirmed by integration with subtype-specific mutations. A transcriptional subtype classifier was then developed by trialling three machine learning algorithms using subtype-specific metagenes defined by NMF. The ability of classifiers to predict subtype was tested using RNA sequencing of a living biobank of patient-derived OC models.ResultsApplication of NMF optimally clustered the 44 cell lines into five transcriptionally distinct groups. Close inspection of orthogonal datasets revealed this five-cluster delineation corresponds to the five major OC subtypes. This NMF-based classification validates the Domcke et al. analysis, in identifying lines most representative of HGSOC, and additionally identifies models representing the four other subtypes. However, NMF of the cell lines into two clusters did not align with the dualistic model of OC and suggests this classification is an oversimplification. Subtype designation of patient-derived models by a random forest transcriptional classifier aligned with prior diagnosis in 76% of unambiguous cases. In cases where there was disagreement, this often indicated potential alternative diagnosis, supported by a review of histological, molecular and clinical features.ConclusionsThis robust classification informs the selection of the most appropriate models for all five histotypes. Following further refinement on larger training cohorts, the transcriptional classification may represent a useful tool to support the classification of new model systems of OC subtypes.

Survival after minimally invasive hysterectomy for type 2 uterine cancer

Objectives: Minimally invasive surgical (MIS) staging has become the standard of care for low-grade clinical stage I endometrioid uterine cancer based on randomized studies demonstrating survival outcomes comparable to laparotomy. However, there is limited data on the use of MIS for high-grade uterine cancers at much higher risk for local disease extension and metastasis. The LACC trial showed inferior survival among early-stage cervical cancer patients undergoing MIS compared to laparotomy. The aim of this study was to test the hypothesis that MIS staging of type 2 uterine cancers would be associated with inferior survival. Methods: The National Cancer Database was used to identify women with type 2 uterine cancer (serous, carcinosarcoma, high-grade endometrioid, clear cell) diagnosed from 2010-2015 who underwent primary surgical management. Patients with low grade endometrioid uterine cancer were excluded. MIS included both laparoscopic and robotic approaches. Inverse probability of treatment weighting (IPTW) was used to balance confounders between the MIS and laparotomy groups. Variables in the propensity score model included age, race, median neighborhood education and income, insurance status, year of diagnosis, tumor stage, size, and grade, medical co-morbidities, facility type, and location. Kaplan-Meier curves and Cox regression were used to compare survival. Results: A total of 54,027 women (mean age 65.0±10.1 years) were included in the analysis. 33,763 (62.5%) underwent MIS approach. Compared to those in the laparotomy group, patients treated with MIS were noted to have tumors that were smaller, had earlier stage disease, and were less likely to be graded as poorly differentiated. Following weighting, the 5 year survival rates were 63.4% for laparotomy and 66.5% for MIS. (Figure 1). Patients treated with an MIS approach demonstrated significantly improved survival compared to an open approach (HR=0.87; 95% CI [0.84, 0.91], p Download : Download high-res image (103KB) Download : Download full-size image Conclusions: MIS staging was performed in two-thirds of patients with type 2 uterine cancer yet with significant baseline differences compared to the laparotomy group. Propensity score weighted matching was used in an attempt to create equivalent cohorts from this large retrospective sample. Our findings support the null hypothesis that MIS staging is not inferior to laparotomy, which are consistent with prior literature on type 1 uterine cancer and reinforce that MIS is the preferred approach for surgical staging of all types of uterine cancer.

Abstract 2267: Alterations in TGFβ signaling in ovarian cancer patients with TGFβ receptor 1 variants

Abstract Transforming growth factor β (TGFβ) signals through the TGFβ Receptor 1 (TGFβR1) and is implicated in many aspects of malignancy. TGFβR1 gene is frequently mutated in ovarian carcinomas (OvCa) (Chen, T., et al, Cancer Research 61, 4679-4682, 2001). Susceptibility to numerous cancers is linked to two germline variants of TGFβR1, a G to A single nucleotide polymorphism in intron 7 (Int 7G24A) and a nine base pair deletion in exon 1 (TGFβR1*6A) although the mechanism(s) for this association is still unclear. Since the canonical pathway for TGFβR1 signaling is via phosphorylation of SMAD, the goal was to determine the association of either or both variants with development of subtypes of OvCa and to measure phosphorylation of pSMAD in the epithelium and stroma of OvCas from women with either or both Int 7G24A and TGFβR1*6A. FFPE tissues from 122 women without a history of cancer, and 59 women with OvCa were obtained from St. Elizabeth Healthcare (N. KY) and from 63 women with OvCa through the Cooperative Human Tissue Network (Birmingham Ala). OvCa patients and non-cancer controls were age matched. St. Elizabeth Healthcare IRB gave permission for this study. Tumors were diagnosed in H&amp;E stained histologic sections by a Board Certified Pathologist (LED) and were classified as either Low Malignant Potential (LMP), Type 1 (clear cell, mucinous and low grade serous and endometrioid) or Type 2 (high grade serous, high grade endometrioid, or carcinosarcoma). Variants were identified in extracted DNA from FFPE tissues using PCR, capillary electrophoresis (CE), RFLP, and SSCP. Histologic sections were stained by IHC using the DAKO LSAB2 kit (Agilent) and anti pSMAD 2 (Millipore AB3849-1). Stain was evaluated as cytoplasmic and nuclear Histoscores (stain Area X Intensity) by two observers (LED, JHC). Data were evaluated by “Gene Code” with Gene 1 wild type for both variants, Gene 2 homozygous or heterozygous for Int 7G24A, Gene 3 homozygous or heterozygous for TGFβR1*6A, and Gene 4 having both variants. Usual chi-tests were used to determine significance of contingency tables, ANOVA with multiple comparison adjusted were used for markers. KM plots and proportional hazards were used in survival tests. The frequency in Gene 1, 2, 3, and 4 was significantly different in controls vs. OvCa patients (p = 0.0010); 57.7% of OvCa patients had a TGFβR1 variant vs. 36.6% of controls. Frequency of TGFβR1 variants in 62 patients with Type 2 OvCa was 62.9%. Patient survival differed significantly between patients with LMP, Type 1, and Type 2 OvCa (p &amp;lt;0.0001). Differences in nuclear expression of pSMAD in both tumor epithelial and stromal cells between OvCa types were highly significant (p &amp;lt; 0.0001, p&amp;lt; 0.0092). pSMAD expression decreased significantly in the nuclei of both epithelial and stromal cells in Type 2 tumors. These data indicate that germline variations in the TGFβR1 gene are associated with high grade ovarian cancers and altered SMAD phosphorylation. Citation Format: Julia H. Carter, James P. Schaeper, Taiping Chen, Diane W. Fritz, Leah Focke, Adrian Guy, James A. Deddens, Larry E. Douglass. Alterations in TGFβ signaling in ovarian cancer patients with TGFβ receptor 1 variants [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2267.

Correlation between pre-operative diagnosis and final pathological diagnosis of endometrial malignancies; impact on primary surgical treatment

Objectivesto compare the accuracy of preoperative and postoperative endometrial sampling obtained by dilatation and curettage (D&C), Pipelle and hysteroscopy to diagnose endometrial malignancies and to evaluate the adequacy of surgical treatment for these patients. Study designThis retrospective record-based study was conducted at Gynecology Oncology Unit, Ain Shams University Maternity Hospital, Cairo, Egypt. Records of patients with an initial preoperative or a final postoperative pathological diagnosis of endometrial hyperplasia or endometrial malignancies were retrieved over a six year period from January 2013 until March 2019. The preoperative biopsy methods, results, postoperative pathology diagnosis and treatment received were recorded and analyzed. ResultsRecords of 395 patients were retrieved. Rates of agreement between initial and postoperative pathology for endometrial hyperplasia (with and without atypia) were 10% by D&C, 7.8% by Pipelle and zero % by hysteroscopy; for endometrioid adenocarcinoma grade 1, they were 40.7% by D&C, 40.6% by Pipelle and 20% by hysteroscopy; for endometrioid adenocarcinoma grades 2 and 3, they were 83.7% and 84.6% by D&C, 97% and 60% by Pipelle, and 100% by hysteroscopy, respectively. For type II endometrial cancer and endometrial stromal sarcoma, agreement rates were 100% by all biopsy methods. Out of 13 cases diagnosed with atrophic endometrium preoperatively, 11 cases were diagnosed as endometrial stromal sarcoma. Comparing accuracy of the three biopsy methods, D&C had highest sensitivity of 61.9%; hysteroscopy showed 100% specificity, while Pipelle was the least accurate method. Finally, 61.4% of the patients received adequate surgical treatment. ConclusionThere were excellent concordance rates between initial biopsy and postoperative pathology in diagnosis of high grade endometrioid and other endometrial malignancies compared to endometrial hyperplasia and low grade endometrioid adenocarcinoma. Patients diagnosed initially with atrophic endometrium or hyperplasia warranted more surveillance before their surgical treatment. It is crucial to develop protocols for increasing accuracy of endometrial sampling such as performing molecular studies for preoperative pathology.

Genetic alterations and their therapeutic implications in epithelial ovarian cancer

BackgroundGenetic alterations for epithelial ovarian cancer are insufficiently characterized. Previous studies are limited regarding included histologies, gene numbers, copy number variant (CNV) detection, and interpretation of pathway alteration patterns of individual patients.MethodsWe sequenced 410 genes to analyze mutations and CNV of 82 ovarian carcinomas, including high-grade serous (n = 37), endometrioid (n = 22) and clear cell (n = 23) histologies. Eligibility for targeted therapy was determined for each patient by a pathway-based approach. The analysis covered DNA repair, receptor tyrosine kinase, PI3K/AKT/MTOR, RAS/MAPK, cell cycle, and hedgehog pathways, and included 14 drug targets.ResultsPostulated PARP, MTOR, and CDK4/6 inhibition sensitivity were most common. BRCA1/2 alterations, PTEN loss, and gain of PIK3CA and CCND1 were characteristic for high-grade serous carcinomas. Mutations of ARID1A, PIK3CA, and KRAS, and ERBB2 gain were enriched in the other histologies. PTEN mutations and high tumor mutational burden were characteristic for endometrioid carcinomas. Drug target downstream alterations impaired actionability in all histologies, and many alterations would not have been discovered by key gene mutational analysis. Individual patients often had more than one actionable drug target.ConclusionsGenetic alterations in ovarian carcinomas are complex and differ among histologies. Our results aid the personalization of therapy and biomarker analysis for clinical studies, and indicate a high potential for combinations of targeted therapies.