High-grade Endometrial Cancer Research Articles

Diagnostic accuracy of frozen section and patterns of nodal spread in high grade endometrial cancer: a secondary analysis of the SENTOR prospective cohort study

<h3>Objectives:</h3> Recent studies have shown that sentinel lymph node (SLN) biopsy accurately detects nodal metastases in patients with high-grade endometrial cancer (EC). SLN biopsy has the potential to replace complete lymphadenectomy for surgical staging in patients with high-grade EC, provided that an SLN algorithm is followed (side-specific pelvic and para-aortic lymphadenectomy for non-mapped hemipelves). The aim of this study was to define the accuracy of intraoperative frozen section for the detection of metastases in SLN biopsy and describe the pattern of lymph node (LN) spread in patients with high-grade EC. <h3>Methods:</h3> We performed a secondary analysis of clinicopathologic data from the SENTOR prospective cohort study evaluating SLN node biopsy at 3 designated cancer centres in Toronto, Canada (ClinicalTrials.gov ID: NCT01886066). Patients with clinical stage I high-grade EC (grade 3 endometrioid, serous, clear cell, carcinosarcoma, undifferentiated, or mixed tumors) undergoing laparoscopic or robotic primary hysterectomy were enrolled. The primary outcome was sensitivity of frozen section of the SLN specimen, compared to a standardized ultrastaging protocol. Secondary outcomes included the pattern and characteristics of LN spread. <h3>Results:</h3> There were 126 patients with high-grade EC with median age 66 years (range: 44-86) and median BMI 26.9 kg/m² (range: 17.6-49.3). Frozen section was performed on surgical specimens from 212 hemipelves; SLNs were identified in 202 specimens (95.7%) and fatty tissue alone was identified in 10 specimens (4.7%). Of the 202 hemipelves in which SLNs were identified, 24 were positive for metastatic disease. Frozen section correctly identified only 12, yielding a sensitivity of 50% (12/24, 95% CI 29.6-70.4) and negative predictive value of 94% (178/202, 95% CI 89-96.5). A total of 24 patients had LN metastases: 16 (13%) had isolated pelvic metastases, 7 (6%) had both pelvic and para-aortic metastases and 1 (0.8%) had an isolated para-aortic metastasis. All para-aortic metastases (n=8) occurred in non-sentinel LNs, among patients with serous (n=5), carcinosarcoma (n=2), and dedifferentiated (n=1) histology. One patient with isolated para-aortic metastases (carcinosarcoma, p53 abnormal) did not have a mapped SLN, but was identified by the SLN algorithm. Nodal metastases occurred in 10% of patients (3/30) with grade 3 endometrioid histology (all pelvic), compared to 33% of patients (15/46) with serous histology (10 pelvic alone, 5 pelvic and para-aortic). <h3>Conclusions:</h3> Intraoperative frozen section of SLNs in high-grade EC patients has poor sensitivity. However, frozen section may still be beneficial to confirm the presence of nodal tissue and ensure adherence to an SLN algorithm, including complete pelvic and para-aortic lymphadenectomy for non-mapped hemipelves. Because isolated para-aortic metastases are rare, para-aortic lymphadenectomy may be omitted in patients in which SLNs were successfully mapped to the pelvis.

Preoperative wait times in high-grade endometrial cancer: do surgical delays impact patient survival?

<h3>Objectives:</h3> Practice guidelines advocating for the regionalization of endometrial cancer surgery to gynecologic oncologists practicing in designated gynecologic oncology centres were released by Cancer Care Ontario in June 2013. We sought to determine the impact this policy had on contemporary surgical wait times. Moreover, a discussion about the impact of delays in treatment has never been more timely than in the context of the current COVID19 pandemic, which has burdened health care systems around the world. Our primary objective was to establish whether longer wait time to surgery is a predictor of survival in patients with high grade endometrial cancer. <h3>Methods:</h3> This was a retrospective cohort study, which included patients diagnosed with non-endometrioid high-grade endometrial cancer (serous, carcinosarcoma, clear cell, and undifferentiated) between 2003 and 2017. A total of 2 regionalization periods were defined, before and after January 2014 to allow 6 months for knowledge translation after guideline publication. Patients were identified in population-based administrative provincial data sources. Multivariable Cox proportional hazards regression with a spline function was used to model the relationship between wait time and overall survival, as measured from time of surgery. <h3>Results:</h3> We identified 3518 patients with high grade endometrial cancer. Median wait time between diagnosis and surgery for the entire cohort did not significantly change with regionalization of care (50 vs 52 days, p=0.14). Patients who had surgery with a gynecologic oncologist had a median surgical wait time from diagnosis to hysterectomy of 55 days compared to 59 days pre-regionalization (p=0.0002), and from first gynecologic oncology consultation to hysterectomy of 29 days compared to 32 days pre-regionalization (p=0.0006). Survival was worst for patients who had surgery within 14 days of diagnosis (HR death 2.7, 95% CI 1.61-4.51 for 1-7 days and HR death 1.96, 95% CI 1.5-2.57 for 8-14 days), indicating disease severity. Decreased survival occurred with surgical wait times of more than 45 days from the patient's first gynecologic-oncology appointment (HR death 1.19, 95% CI 1.04-1.36 for 46-60 days and HR death 1.42, 95% CI 1.11-1.82). <h3>Conclusions:</h3> Regionalization of surgery for high grade endometrial cancer has not had a negative impact on surgical wait times. Impact on survival is seen with patients who have surgery more than 45 days after surgical consultation.

Multi-dimensional biomarker analyses identify pembrolizumab responders in advanced-stage, high-grade endometrial cancer

<h3>Objectives:</h3> The recent FDA approval of pembrolizumab for the treatment of recurrent, tissue agnostic cancers with Microsatellite Instability-High (MSI-H) or Mismatch Repair Deficient (dMMR) has led to the treatment of a selected cohort of endometrial cancer (EC) patients. <h3>Methods:</h3> We designed a study to ascertain tumor immune modulatory effects of pembrolizumab in the front-line setting for advanced stage III/IV surgically-resectable endometrial cancers regardless of MSI-H or dMMR status. The primary objectives were to determine the safety of treatment with pembrolizumab by radiographic imaging and to determine progression-free survival at 6 months. Exploratory objective was to compare the immune response before and after treatment. In an open label, single-arm Phase I trial, 8 EC patients were treated with 2 doses of preoperative pembrolizumab IV prior to surgery followed by carboplatin and paclitaxel and 4 doses of pembrolizumab 200mg/kg q3 weeks IV. Peripheral blood was collected from EC patients at baseline level before treatment and post 2 doses of pembrolizumab treatment. Blood from healthy controls (HC) was also collected. Both were processed for high-dimensional single-cell mass cytometry (CyTOF) using an optimized lymphoid and myeloid panel. <h3>Results:</h3> Patients who responded to therapy showed lower frequency of circulating CD8+ naïve T cells but higher frequency of CD8+ effector T cells after the treatment than the poor responders. We observed post-therapy expansion of populations of CD8+ and CD4+ T cells expressing co-stimulatory receptor ICOS in responders but not in poor responders. Granzyme+CD8+ and Granzyme+CD4+ T cell populations were expanded after pembrolizumab treatment in responders but were decreased in poor responders. Higher frequency of CD27+Fas- CD4+ T cells at baseline and increased frequency of CD27-Fas+CD4+ T cells post-treatment were observed in responders but not in the poor responders. Furthermore, we identified that circulating MDSCs were reduced after pembrolizumab treatment in responders. <h3>Conclusions:</h3> Our results suggest that peripheral blood analysis may provide valuable insights into responses to anti-PD-1-targeted therapies in patients with endometrial cancers.

Racial differences in patient-reported distress among women with endometrial cancer

Objectives: There are established racial disparities in mortality from endometrial cancer (EC). In addition, distress from cancer diagnosis and treatment is associated with lower compliance and more frequent use of emergency services. Differences in distress by race/ethnicity in EC have not been previously explored. Here we characterize the association between race/ethnicity, distress scores and stressors reported by patients on the National Comprehensive Cancer Network Distress Thermometer and Problem List (NCCN DT), and referral to support services in women with EC. Methods: Patients presenting to a single academic outpatient gynecologic oncology practice for initial evaluation of known EC from January 2013-May 2020 were included. The electronic health record was used to abstract demographics, NCCN DT scores, and stressor categories (physical, emotional, spiritual, practical, and family) from the initial encounter. At our institution, patients are referred to support services for an NCCN DT score ≥4. We excluded women who received prior cancer-directed therapy and those without an NCCN DT score recorded at their initial appointment. Summary statistics were tabulated for demographics. Mann-Whitney U tests were used for inter-group difference on continuous variables and 2-sample tests for equality of proportions were used for binary variables. Results: 412 non-Hispanic White (NHW, mean age 63) and 149 non-Hispanic Black (NHB, mean age 65) women were included in our analysis. More NHB women presented with high-grade EC (53.7%) vs NHW women (21.9%) and fewer NHB women were privately insured (32% vs 52%). Median distress scores were higher in NHW women compared to their NHB counterparts (4 vs. 2, p Conclusions: The NCCN DT, a widely used tool in cancer clinics, may fail to adequately measure distress in NHB women presenting with a diagnosis of EC, despite >30% more high risk histology cancers in this cohort. This phenomenon appears to be driven by the greater frequency of ‘0’ distress scores reported by NHB women. This difference leads to disparities in referral to additional support services, which may affect quality of care and quality of life. Additional research is needed to better understand how women of different races and ethnicities approach the NCCN DT.

Phosphoproteomic response mapping to anti-angiogenic agents bevacizumab and cediranib in high-grade serous ovarian and endometrial cancer cell lines

<h3>Objectives:</h3> Antiangiogenics have become a cornerstone of treatment in advanced stage and recurrent high grade serous ovarian cancer. Both cediranib (ICON6) and bevacizumab (ICON7, GOG218) have demonstrated benefit as a maintenance treatment for ovarian cancer patients in clinical trials. Investigators have also explored their role in advanced stage and recurrent endometrial carcinoma (MITO-END 2, Rose 2017, Aghajanian 2011). There have been no head to head trials in gynecologic cancers comparing cediranib to bevacizumab, although in colorectal carcinoma, phase III data suggests equivalent efficacy (HORIZON III). We hypothesize that these drugs, although both categorized as anti-angiogenics, induce unique cellular responses and sought to explore the varying impact of each agent on cell signaling using established serous cell models. <h3>Methods:</h3> CAOV3 ovarian cancer cells and Hec50 endometrial cancer cells were exposed to 1µM bevacizumab or cediranib for 24 hours. Cell lysates were analyzed in duplicate using an antibody-based phosphoproteomic array of 875 phosphoproteins supplied by Kinexus Bioinformatics (Vancouver, BC). Priority signaling effects were defined for each drug and in each cell line as those with a significant (>75%) change from control with an acceptable sum of error (<75%). <h3>Results:</h3> Bevacizumab yielded 13 total leads, and cediranib yielded 9 in CAOV3 ovarian cancer cells (Table 1). Both agents significantly enhanced signaling events on the following epitopes: ABl, EZH2, HGK (2 sites), and IGF1R, indicating that these may be some of the core cellular effects of anti-angiogenic agents. Interestingly, all common leads induced by both agents in CAOV3 cells represent potential pro-oncogenic effects. In Hec50 cells (Table 1), both cediranib and bevacizumab treatment induced a unique set of phosphoproteins compared to the effects of these agents in CAOV3 cells, yet common findings were the phosphorylation of IGFR1 by bevacizumab and the activation of alternative MAP kinases in both cell lines. <h3>Conclusions:</h3> Angiogenesis plays a crucial role in tumor development and metastasis. Blocking angiogenesis using monoclonal antibodies such as bevacizumab or tyrosine kinase inhibitors such as cediranib is a strategy that is proving to be helpful in the care of patients with gynecologic malignancies. These molecular agents have both on-target, therapeutic effects but also may induce pathways of resistance. In these comprehensive phosphoproteomic mapping studies, we noted the activation of signaling pathways which were cell and drug specific. One consistent finding was the enhanced phosphorylation of IGFR1 and alternative MAP kinases that may portend eventual drug resistance.

Factors influencing treatment decision and guideline conformity in high-grade endometrial cancer patients: a population-based study.

Treatment according to guidelines has been demonstrated to improve survival in a number of different cancer entities. Deviations from guidelines depend on several factors, including the patient's preferences, age and comorbidities. The aim of this study was to assess the adherence to guideline recommendations concerning surgical and adjuvant treatment in endometrial cancer. Furthermore, we sought to evaluate the reasons for non-adherence to guidelines by further examining the influence of comorbidities and age. The influence of age, comorbidities, tumor stage and histological subtype on guideline adherence was evaluated by multivariable logistic regression in a cohort of 353 high-grade endometrial cancer patients. High-grade endometrial cancer was defined as carcinosarcoma, Type II (serous, clear cell, mixed cell carcinoma) and Type I G3 histology. Extensive surgical procedures, particularly systematic LNE, were less frequently applied in patients with comorbidities (p = 0.015) or higher age (p < 0.01). Guideline adherence was not affected by comorbidities (p = 0.563), but was significantly reduced with higher age (p < 0.01). In a multivariable model, higher age (p < 0.01), obesity (p = 0.011), higher FIGO Stage (p < 0.01) and histologic subtype (p < 0.01) significantly decreased OS. Surgery (p < 0.001), chemotherapy (p < 0.01) and systematic LNE (p = 0.011) were associated with higher OS. Age seems to be the strongest independent factor leading to guideline deviation. Comorbidities were associated with less aggressive treatment, but not with deviations from guidelines.

Abstract LB236: Utilizing endometrial tumor organoids to model cancer immunomodulation

Abstract Endometrial cancer is the most common gynecologic malignancy in the United States. Most women present with early stage disease and have a favorable prognosis. However, the treatment options for recurrent endometrial cancer is limited. Immunotherapy has become increasingly popular in the treatment of recurrent endometrial cancer. A hallmark of malignant cells is immune-evasion at both the genetic level and in the tumor microenvironment. We hypothesized that an endometrial cancer organoid model could be utilized to study the tumor immune microenvironment. Major Histocompatibility Complex (MHC) is a protein receptor recognized with its antigen by immune cells to screen either non-self or tumorous cells. It has a crucial role in eliminating non-self cells, such as cancer cells. We first assessed the genes involved in the regulation of MHC I and II in cultured normal and tumor organoids. RNA-Sequencing of fifty-six patients from our living organoid biobank were analyzed and we found an immunologic cluster of high-grade endometrial cancers that display significant downregulation in both MHC I and II. This was confirmed with real time-PCR which showed that high-grade cancers organoids had downregulated MHC I and II compare to organoids derived from low-grade cancer tissues and benign tissues. We next sought to demonstrate that both normal and endometrial cancer organoids retain the ability to present external antigen by using DQ-Ovalbumin. We demonstrated that endometrial organoids retain the ability to present antigen, but cancer organoids display reduced efficiency in the antigen processing. Next, we stimulated endometrial cancer organoids with interferon-gamma (IFNg), a well known cytokine for enhancing immunological response, to increase the expression of MHC I and II in cancer organoids. IFNg led to a 2-6 fold increase in MHC expression in low-grade cancer organoids, but a 5-40 fold increase in expression in high-grade cancer organoids utilizing real time-PCR. Finally, we implement the organoid-immune cell co-culture system with patient-derived organoids and CD8+ cytotoxic T-Cells in the allogeneic and syngeneic settings. Endometrial cancer organoids and matched patient-derived cytotoxic T-Cells were co-cultured for 48 hours and imaged for 16 hours. Both migratory effect and tumor killing effect were compared. As expected, in the allogeneic setting CD8+ T-Cells efficiently colocalized and killed cancer cells in the vehicle and IFNg stimulated groups. In the syngeneic setting, CD8+ T-Cells did not colocalize or kill cancer cells in the vehicle, whereas they significantly colocalized and killed cancer cells when stimulated with IFNg. Our data demonstrate that high-grade endometrial cancer cells downregulate MHC I and II, suggesting that they can evade the host immune system. We also showed that this effect is patient-specific and can be overcome by stimulating with interferon-gamma. Furthermore, we demonstrated that increasing MHC I and II among cancer organoids enhances the target cell recognition and apoptosis induction by CD8+ T-cells. Collectively, our finding offers an approach to study the tumor microenvironment that can be individualized for each patient through the use of patient-derived cancer organoids. This technology can be further developed to study targeted therapies and provides a much needed pre-clinical model for the study of endometrial cancer. Citation Format: Aaron Nizam, Charlie Chung, Gary L. Goldberg, Semir Beyaz. Utilizing endometrial tumor organoids to model cancer immunomodulation [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 LB236.

Factors associated with an increased risk of recurrence in patients diagnosed with high-grade endometrial cancer undergoing minimally invasive surgery: A study of the society of gynecologic oncology of Canada (GOC) community of practice (CoP)

BackgroundMinimally invasive surgery (MIS) is a standard surgical approach for comprehensive surgical staging in women with endometrial cancer. As rates and complexity of MIS are steadily increasing, it is important to identify potential risk factors which may be associated with this approach. This study evaluates the impact of local factors on the risk of disease recurrence. MethodsA retrospective cohort study was conducted of patients diagnosed with high grade endometrial cancer (HGEC) who underwent MIS between 2012 and 2016 at eight Canadian centers. Data was collected from medical records. The 75th percentile was calculated for estimated uterine volume and weight. All recurrences were categorized into two groups; intra-abdominal vs. extra-abdominal. To search for significant covariates associated with recurrence-free survival a Cox proportional hazard model was performed. ResultsA total of 758 patients were included in the study. Intra-uterine manipulator was used in 497 (35.8%) of patients. Vaginal lacerations were documented in 9.1%. Median follow-up was 30.5 months (interquartile range 20–47). There were 157 who had disease recurrence (20.71%), including 92 (12.14%) intra-abdominal and 60 (7.92%) extra-abdominal only recurrences. In univariate analysis myometrial invasion, LVI, stage, uterine volume and weight > 75th percentile and chemotherapy were associated with increased risk of intra-abdominal recurrence. In multivariable analysis only stage, and specimen weight > 75th percentile (OR 2.207, CI 1.123–4.337) remained significant. Uterine volume, and weight were not associated with increased risk of extra-abdominal recurrences. ConclusionFor patients diagnosed with HGEC undergoing MIS, extracting a large uterus is associated with a significantly increased risk for intra-abdominal recurrence.

Personalized tumor-specific DNA junctions to detect circulating tumor in patients with endometrial cancer.

There are no reliable blood biomarkers for monitoring endometrial cancer patients in the current clinical practice. Circulating tumor DNA (ctDNA) is emerging as a promising non-invasive method to measure tumor burden, define prognosis and monitor disease status in many solid cancers. In this pilot study, we investigated if unique tumor-specific DNA junctions can be used to detect ctDNA levels in patients with endometrial cancer. Chromosomal rearrangements in primary tumors of eleven patients with high-grade or advanced stage endometrial cancer were determined by whole-genome Mate-Pair sequencing. Identified unique tumor-specific junctions were evaluated in pre- and six-week post-surgery patient plasma using individualized quantitative polymerase chain reaction (qPCR) assays. The relationship between clinicopathological features and detection of ctDNA was investigated. CtDNA was detected in 60% (6/10) of cases pre-surgery and in 27% (3/11) post-surgery. The detection of ctDNA pre-surgery was consistent with clinical indicators of aggressive disease such as advanced stage (80% - 4/5), lymphatic spread of disease (100% - 3/3), serous histology (80% - 4/5), deep myometrial invasion (100% - 3/3), lympho-vascular space invasion (75% - 3/4). All patients in which ctDNA was detected post-surgically had type II endometrial cancer. This pilot study demonstrates the feasibility of using personalized tumor-specific junction panels for detecting ctDNA in the plasma of endometrial cancer patients. Larger studies and longer follow-up are needed to validate the potential association between pre-surgical ctDNA detection and the presence of cancers with aggressive pathologic tumor characteristics or advanced stage observed in this study.

MiR-501 promotes tumor proliferation and metastasis by targeting HOXD10 in endometrial cancer

BackgroundSeveral studies have shown the crucial role of miR-501 in regulating cellular pathology in various cancers. However, the function and expression of miR-501 in endometrial cancer (EC) remain obscure.MethodsThe expression of miR-501 was determined using quantitative real-time PCR. MTT assay, colony formation assay and cell cycle analysis were used to evaluate the proliferation ability. Migration and invasion were assessed using transwell assay. Tumor formation in nude mice was used to observe the effects of miR-501 on cell proliferation and migration in vivo. Luciferase assay, quantitative real-time PCR and western blot were applied to determine that HOXD10 was the target gene of miR-501.ResultsIn this study, we observed significantly up-regulated expression of miR-501 in endometrial cancer, which correlated with higher pelvic lymph node metastasis and shorter overall survival in high-grade endometrial cancer. High expression of miR-501 was also found in the copy-number-high group than other groups. Moreover, in vitro and in vivo assay showed that overexpression of miR-501 can promote proliferation and metastasis. Mechanistically, we found that miR-501 promotes tumor progression by directly targeting HOXD10. Further study also indicated that miR-501 overexpression can activate the AKT/mTOR pathway.ConclusionsMiR-501, which functions as an oncomir in endometrial cancer, might be a potential therapeutic target in high grade endometrial cancer.

Disparities in adjuvant treatment of high-grade endometrial cancer.

e17572 Background: To examine surgical outcomes, patterns of adjuvant therapy, and survival for non-Hispanic Black (NHB) women compared to non-Hispanic White (NHW) and Hispanic (HS) women who have undergone surgery for high grade endometrial cancer in the Medicare population. Methods: We utilized the SEER-Medicare linked database to identify women who underwent surgery as a primary treatment for uterine grade 3 endometrioid adenocarcinoma, carcinosarcoma, clear cell carcinoma, or serous carcinoma between the years 2000 and 2015. Multinomial logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI) for receiving a treatment delay or not receiving adjuvant treatment (compared to those who received adjuvant treatment within 12 weeks) adjusted for clinical and demographic characteristics. Overall survival (OS) stratified by race/ethnicity, route of surgery, operative complications, and type and timing of adjuvant therapy were analyzed using the Kaplan-Meier method. Cox Proportional hazards regression was used to estimate hazard of death by race/ethnicity adjusted for known predictors, as well as surgical outcomes and adjuvant therapy patterns. Results: 12, 201 women met study inclusion criteria. NHB patients had a significantly worse five-year overall survival (OS) than HS and NHW patients (30.9 months vs 51.0 months vs 53.6 months, respectively). Approximately 8.6% of patients who received adjuvant treatment experienced a treatment delay (632/7, 282). Delay in treatment of greater than or equal to 12 weeks was significantly different by race/ethnicity (p=0.034), with 12% of HS, 9% of NHB, and 8% of NHW women experiencing a delay. After adjustment for number of complications, age, histology (endometrioid v. non-endometroid), FIGO stage, marital status, comorbidity count, surgical approach, lymph node dissection, and urban-rural code, HS had a 71% increased risk of treatment delay (OR 1.71, CI 1.23-2.38) for all stages of disease. In the same model, NHB race was independently predictive of decreased use of adjuvant treatment for FIGO stage II and higher (OR 1.32, CI 1.04-1.68). NHB race, number of perioperative complications, and non-endometrioid histology were predictive of worse OS in univariate models. Treatment delay was not independently predictive of worse 1- or 5-year survival at any stage. Conclusions: NHB race is predictive of worse 5-year survival across all stages and is also associated with omission of adjuvant treatment in ≥FIGO Stage II high grade endometrial cancers. HS ethnicity was associated with treatment delay across all stages. In unadjusted analyses, patients who experience treatment omission or delay experienced poorer OS, but these factors were not independently associated in multivariate analyses.

Computational features of TIL architecture are differentially prognostic of uterine cancer between African and Caucasian American women.

5585 Background: Although the vast majority of endometrial cancer (EC) is early-stage and thus, curable by surgery, chemotherapy, and radiotherapy (with at least 85% 5-year OS), a fraction of them are aggressive neoplasms such as high-grade or deeply invasive lesions and thus exhibit poor prognosis. African American (AA) women are disproportionately affected by high-grade EC and have 80% higher mortality rate compared with Caucasian American (CA) women. In this work, we evaluated the prognostic ability of computational measurements of architecture of tumor-infiltrating lymphocytes (ArcTIL) from H&amp;E slide images for EC. We also investigated the presence of morphologic differences in terms of ArcTIL features between AA and CA women and whether ArcTIL based population-specific models were more prognostic of OS in AA women compared to a population-agnostic model. Methods: The study included digitized H&amp;E tissue slides from 445 post-surgery EC patients from TCGA, with further chemotherapy, or radiotherapy, including only the AA and CA patients, patients without reported race or from other populations were excluded. The dataset was divided into discovery (D1, n = 300), and a validation set (D2, n = 145), while ensuring population balance between two splits (D1(AA) = 65, D1(CA) = 235, D2(AA) = 37, D2(CA) = 108). A machine learning approach was employed to identify tumor regions, and tumor-associated stroma on the diagnostic slides and then used to automatically identify TILs within these compartments. Graph network theory based computational algorithms were used to capture 85 quantitative descriptors of the architectural patterns of intratumoral and stromal TILs. A multivariable Cox regression model (MCRM) was used to create population specific-prognostic models (MAA, MCA) and a population-agnostic model (MAA+CA)) to predict OS. All 3 models were evaluated on D2(AA), D2(CA), and D2. Results: MAA identified 4 prognostic features relating to interaction of TIL clusters with cancer nuclei in stromal compartment and was prognostic of OS on D2(AA) (see Table) but not prognostic in D2(CA) nor D2(AA+CA). MCA and MAA+CA identified respectively 7 and 6 prognostic features relating to interaction of TIL clusters with cancer nuclei (both in the epithelial and stromal regions) and were prognostic of OS on D2(CA) and D2, but not prognostic in D2(AA). Conclusions: Our findings suggest an important role of stromal TIL architecture in prognosticating OS in AA women with EC, while epithelial TIL features were more prognostic in CA women. These findings need to be validated in larger, multi-site validation sets.[Table: see text]

Comparison of survival outcomes and effects of therapy between subtypes of high-grade endometrial cancer – a population-based study

Background Similarities in outcome between grade 3 endometrioid cancer and non-endometrioid histologies have been reported by a number of studies. Other reports, however, stated a significantly better prognosis for G3 endometrioid compared to type II histology. In this population-based study, we compared the outcome and treatment approaches of high-grade endometrial cancer patients with FIGO stages I–III depending on their histology. Material and methods 284 high-grade endometrial cancer patients diagnosed between 1998 and 2015 were retrospectively analyzed. Overall survival (OS), recurrence-free survival (RFS), and recurrence rates were compared depending on histology. Results Type I G3 patients had a statistically significant OS advantage over women suffering from type II carcinoma (HR 1.527, 95%-CI 1.024–2.276; p = 0.038) and carcinosarcoma (HR 2.106, 95%-CI 1.270–3.493; p = 0.004) in univariable and multivariable Cox-regression analysis. RFS in Type I G3 was significantly superior compared to patients with carcinosarcoma (HR 1.719, 95%-CI 1.018–2.901; p = 0.043) and not significantly superior to type II patients (HR 1.368, 95%-CI 0.920–2.036; p = 0.122). Cumulative recurrence rates were significantly higher in carcinosarcoma compared to type I G3 (HR 2.217, 95%-CI 1.096–4.485; p = 0.027) in univariable analysis, but not after risk adjustment (HR of 1.472, 95%-CI 0.654–3.311; p = 0.350). Conclusion The prognosis of patients with type I G3 endometrial cancer patients seems to be significantly superior to patients with type II cancer and particularly carcinosarcoma. Systematic LND seemed to be beneficial in all of the three subtypes. The benefit of adjuvant treatment methods may differ between histologies.

Evaluation of Survival, Recurrence Patterns and Adjuvant Therapy in Surgically Staged High-Grade Endometrial Cancer with Retroperitoneal Metastases.

Simple SummaryHigh-grade endometrial carcinomas present a clinical challenge due to their propensity to metastasize beyond the pelvis. Stage IIIC disease represents a unique entity relative to all other stages, as the retroperitoneal lymph nodes are involved. Prior randomized controlled trials have suggested that chemotherapy alone is sufficient to treat stage III and IV endometrial carcinoma. However, no prospective trial has specifically evaluated adjuvant therapy strategies in stage IIIC disease; therefore, it is difficult to generalize the results of trials including all advanced stage patients to this unique group. In the present study, we observed improved progression-free and overall survival in those patients with stage IIIC disease receiving a combination of both chemotherapy and radiation, suggesting that radiation plays a key role in the management of retroperitoneal metastasis and should be considered in addition to chemotherapy.Background: We seek to evaluate the difference in recurrence patterns and survival among stage IIIC high-grade endometrial cancer treated with surgery followed by adjuvant chemotherapy alone, radiation therapy alone, or both (chemoradiation). Methods: A multicenter retrospective analysis of surgically staged IIIC HGEC receiving adjuvant therapy was conducted. HGEC was defined as grade 3 endometrioid adenocarcinoma, serous, clear cell and carcinosarcoma. Differences in the frequency of recurrence sites and treatment delays were identified using Pearson’s χ2 test. Progression-free survival (PFS) and overall survival (OS) were calculated using Kaplan–Meier estimates. Results: A total of 155 patients were evaluable: 41.9% carcinosarcoma, 36.8% serous, 17.4% grade 3 and 3.9% clear cell. Of these, 67.1% received chemoradiation, 25.8% received chemotherapy and 7.1% received radiation therapy. There was no difference in the frequency of treatment delays between regimens (p = 0.571). There was a trend towards greater retroperitoneal recurrence with chemotherapy (25.9%) versus chemoradiation (8.4%) and radiation therapy (7.7%) (p = 0.252). Grade 3 tumors had improved progression-free and overall survival (26 and 42 months, respectively) versus serous (17 and 30 months, respectively), carcinosarcoma (14 and 24 months, respectively) and clear cell (24 and 30 months respectively) (p = 0.002, p < 0.001). Overall, chemoradiation was superior to chemotherapy and radiation therapy in PFS (p < 0.001) and OS (p < 0.001). Upon multivariate analysis, only histology and receipt of chemoradiation were independent predictors of survival. Conclusion: The majority of stage IIIC high-grade endometrial carcinomas recurred. Chemoradiation was associated with improved survival and less retroperitoneal recurrence. Grade 3 tumors demonstrated improved survival versus other histologies regardless of adjuvant treatment modality.

POLE and Mismatch Repair Status, Checkpoint Proteins and Tumor-Infiltrating Lymphocytes in Combination, and Tumor Differentiation: Identify Endometrial Cancers for Immunotherapy.

ObjectiveAlthough Polymerase-epsilon (POLE)-mutated and mismatch repair (MMR)-deficient endometrial cancers (ECs) are considered as promising candidates for anti-PD-1/PD-L1 therapy, selecting only these patients may exclude other patients who could potentially respond to this treatment strategy, highlighting the need of additional biomarkers for better patient selection. This study aims to evaluate potential predictive biomarkers for anti-PD-1/PD-L1 therapy in addition to POLE mutation (POLEm) and MMR deficiency (MMRd).MethodsWe performed next generation sequencing for POLE from 202 ECs, and immunohistochemistry for MLH1, MSH2, MSH6, PMS2, CD3, CD8, PD-1 and PD-L1 on full-section slides from these ECs. We assessed the association of POLEm and MMRd with clinicopathologic features, expression of check point proteins, and density of tumor-infiltrating lymphocytes (TILs). Prognostic impact of these immune markers was also evaluated.ResultsPOLEm, MMRd and high-grade tumors exhibited elevated level of TILs. Increased expression of PD-1 and PD-L1 was observed in MMRd and high-grade ECs. A subgroup of MMR proficient ECs also harbored increased density of TILs, and positive expression of PD-1 and PD-L1. In addition, negative expression of checkpoint proteins and high density of TILs in combination was associated with good prognosis.ConclusionsCandidates for PD-1 blockade may extend beyond POLEm and MMRd ECs, additional factors such as tumor grade, and combination of TILs levels and expression of checkpoint proteins may need to be considered for better patient selection.

92741 Racial differences in patient-reported distress among women with endometrial cancer

ABSTRACT IMPACT: This work will inform and improve the way we assess and treat distress in women with endometrial cancer. OBJECTIVES/GOALS: Distress from cancer is associated with worse processes of care. Differences in outcomes by race/ethnicity in endometrial cancer (EC) are well documented, but differences in distress have not been previously explored. Here we characterize the association between race/ethnicity, distress scores, and stressors reported by patients with EC. METHODS/STUDY POPULATION: Patients presenting to a single academic outpatient gynecologic oncology practice for initial evaluation of known EC from January 2013-May 2020 were included. The electronic health record was used to abstract demographics, National Comprehensive Cancer Network Distress Thermometer and Problem List (NCCN DT) scores and stressor categories (physical, emotional, spiritual, practical, and family) from the initial encounter. Referral to support services occurs at NCCN DT score ≥4. We excluded women who received prior cancer-directed therapy and those without an initial NCCN DT score. Summary statistics were tabulated for demographics. Mann-Whitney U tests were used for inter-group difference on continuous variables and 2-sample tests for equality of proportions were used for binary variables. RESULTS/ANTICIPATED RESULTS: 412 non-Hispanic White (NHW, mean age 63) and 149 non-Hispanic Black (NHB, mean age 65) women were included in our analysis. More NHB women presented with high-grade EC (53.7%) vs NHW women (21.9%) and fewer NHB women were privately insured (32% vs 52%). Median distress scores were higher in NHW women compared to their NHB counterparts (4 vs. 2, p&lt;0.001) and NHB women were more likely to report a distress score of 0 compared to their NHW counterparts (32% vs 19%, p=0.001). 50.5% NHW women had a score ≥4 and thus qualified for referral to services compared to 20.7% of NHB women (p=0.02). Of those referred, NHB and NHW women declined referral to support services at similar rates (35.1% vs 34.5%; NS). There was a significant difference in the median number of stressors reported by NHW and NHB women, (4 vs 3 stressors; p=0.02). DISCUSSION/SIGNIFICANCE OF FINDINGS: The NCCN DT, a widely used tool in cancer clinics, may fail to adequately measure distress in NHB women presenting with a diagnosis of EC, despite &gt;30% more high-risk histology cancers in this cohort. This difference leads to disparities in referral to additional support services, which may affect quality of care and quality of life.

The role of sarcopenic obesity in high-grade endometrial cancer.

To investigate the relationship between obesity and sarcopenia in relation to overall survival (OS) and disease-specific survival (DSS) in high-grade endometrial cancer patients. We conducted a retrospective study in women diagnosed with high-grade endometrial cancer (EC) between February 2006 and August 2017 in the Royal Cornwall Hospital who had abdominal computerized tomography (CT)-scan as part of routine staging work-up. Sarcopenia was assessed by measuring psoas-, paraspinal- and abdominal wall muscles on CT and defined by skeletal muscle index ≤41cm2 /m2 . Sarcopenic obesity was defined as sarcopenia combined with body mass index (BMI) ≥30kg/m2 . A total of 176 patients with median age of 70years and median BMI of 29.4kg/m2 were included in the study. The majority of patients (38%) had endometrioid type histology. Sarcopenia was not associated with OS (P=0.951) or DSS (P=0.545) However, in multivariate analysis, sarcopenic obesity was associated with reduced OS in endometrioid endometrial cancer (EEC) patients (P=0.048). Sarcopenic obesity is associated with OS in high-grade EEC patients, while sarcopenia without obesity is not related to OS or DSS in high-grade EC. In non-endometrioid endometrial cancer, there is no association between sarcopenic obesity and survival.

Low Expression of miR-375 and miR-190b Differentiates Grade 3 Patients with Endometrial Cancer.

Endometrial cancer (EC) is treated according to the stage and prognostic risk factors. Most EC patients are in the early stages and they are treated surgically. However some of them, including those with high grade (grade 3) are in the intermediate and high intermediate prognostic risk groups and may require adjuvant therapy. The goal of the study was to find differences between grades based on an miRNA gene expression profile. Tumor samples from 24 patients with grade 1 (n = 10), 2 (n = 7), and 3 (n = 7) EC were subjected to miRNA profiling using next generation sequencing. The results obtained were validated using the miRNA profile of 407 EC tumors from the external Cancer Genome Atlas (TCGA) cohort. We obtained sets of differentially expressed (DE) miRNAs with the largest amount between G2 to G1 (50 transcripts) and G3 to G1 (40 transcripts) patients. Validation of our results with external data (TCGA) gave us a reasonable gene overlap of which we selected two miRNAs (miR-375 and miR190b) that distinguish the high grade best from the low grade EC. Unsupervised clustering showed a high degree of heterogeneity within grade 2 samples. MiR-375 as well as 190b might be useful to create grading verification test for high grade EC. One of the possible mechanisms that is responsible for the high grade is modulation by virus of host morphology or physiology.

Abstract PR004: Multi-dimensional biomarker analyses identify pembrolizumab responders in advanced stage, high grade endometrial cancer

Abstract Objectives: The recent FDA approval of pembrolizumab for the treatment of recurrent, tissue agnostic cancers with Microsatellite Instability-High (MSI-H) or Mismatch Repair Deficient (dMMR) has led to the treatment of a selected cohort of endometrial cancer (EC) patients. Methods: We designed a study to ascertain tumor immune modulatory effects of pembrolizumab in the front-line setting for advanced stage III/IV surgically-resectable endometrial cancers regardless of MSI-H or dMMR status. The primary objectives were to determine the safety of treatment with pembrolizumab by radiographic imaging and to determine progression-free survival at 6 months. Exploratory objective was to compare the immune response before and after treatment. In an open label, single-arm Phase I trial, 8 EC patients were treated with 2 doses of preoperative pembrolizumab IV prior to surgery followed by carboplatin and paclitaxel and 4 doses of pembrolizumab 200mg/kg q3 weeks IV. Peripheral blood was collected from EC patients at baseline level before treatment and post 2 doses of pembrolizumab treatment. Blood from healthy controls (HC) was also collected. Both were processed for high-dimensional single-cell mass cytometry (CyTOF) using an optimized lymphoid and myeloid panel. Results: Patients who responded to therapy showed lower frequency of circulating CD8+ naïve T cells but higher frequency of CD8+ effector T cells after the treatment than the poor responders. We observed post-therapy expansion of populations of CD8+ and CD4+ T cells expressing co-stimulatory receptor ICOS in responders but not in poor responders. Granzyme+CD8+ and Granzyme+CD4+ T cell populations were expanded after pembrolizumab treatment in responders but were decreased in poor responders. Higher frequency of CD27+Fas- CD4+ T cells at baseline and increased frequency of CD27-Fas+CD4+ T cells post-treatment were observed in responders but not in the poor responders. Furthermore, we identified that circulating MDSCs were reduced after pembrolizumab treatment in responders. Conclusions: Our results suggest that peripheral blood analysis may provide valuable insights into responses to anti-PD-1-targeted therapies in patients with endometrial cancers. Citation Format: Katherine Fuh, Elena Lomonosova, Russell Pachynski, Olga Malkova, Stephen Oh, Andrea Hagemann, Carolyn McCourt, Matthew Powell, Wendy Fantl, Premal Thaker. Multi-dimensional biomarker analyses identify pembrolizumab responders in advanced stage, high grade endometrial cancer [abstract]. In: Proceedings of the AACR Virtual Special Conference: Endometrial Cancer: New Biology Driving Research and Treatment; 2020 Nov 9-10. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(3_Suppl):Abstract nr PR004.

Abstract PO037: Identifying effective combinations of targeted therapies, using novel pre-clinical models, to improve treatment options for high-grade serous endometrial cancer

Abstract High-grade serous endometrial carcinoma (HGSEC) accounts for just 10% of endometrial cancer (EC) cases but is responsible for at least 40% of all EC-related deaths. It typically arises in post-menopausal women, with 70% of patients presenting with stage III or IV disease, does not respond to hormone therapy unlike the less aggressive forms of EC, and has a lower overall survival rate of just 18-27%, which has not improved over the past two decades. The primary treatment for HGSEC is surgery, followed by a combination of standard chemotherapies (platinum and taxane) with or without localised radiotherapy. However, recurrent HGSEC is less responsive to chemotherapy than are other subtypes of EC and even initial responses to chemotherapy are poor. Therefore, there is a great unmet clinical need to find better treatment options for women with this aggressive cancer. Apart from TP53 (mutated in up to 90% of cases), the other most frequently mutated genes in HGSEC are PPP2R1A (31%), PIK3CA (22%), FBXW7 (28%), CHD4 (17%) and BRCA2 (12%). Focal amplifications of the genes MYC, ERBB2, CCNE1, FGFR3 and SOX17 are also common. The presence of ERBB2 amplification and/or HER2 over-expression in around 30% of HGSEC suggests these patients may respond to HER2-targeting drugs, such as trastuzumab. However, only modest benefit has so far been seen for single-agent HER2-targeted therapies (ie trastuzumab or lapatinib) against HGSEC, suggesting resistance mechanisms are present. Another feature of HGSEC that could be exploited therapeutically is homologous recombination deficiency (HRD), which may be targeted with PARP inhibitors (PARPi). It is not clear what proportion of HGSEC are HRD and neither HER2-targeting drugs or PARPi have been approved for the treatment of HGSEC. Due to its rarity and a lack of pre-clinical models, HGSEC has so far been understudied, resulting in a lack of effective treatment options. We currently have 33 HGSEC patients consented to the WEHI-Stafford Fox Rare Cancer Program and have developed pre-clinical models from fresh patient tumour samples received (4 patient-derived xenograft (PDX) models validated, with 3 pending). Preliminary molecular analysis of whole-genome sequencing (5 samples, one of which gave rise to a PDX model), whole-exome sequencing (4 samples), and cancer panel sequencing (3 samples, 2 of which gave rise to PDX models; one harbouring ERBB2 amplification and one harbouring an AKT mutation) data from our HGSEC cohort has been performed. This has identified potential treatment targets, including ERBB2 amplifications and mutations in HR genes. I am using the PDX models for initial in vivo therapeutic characterization studies and to develop organoid models for use in high-throughput drug assays in vitro. This will guide subsequent novel drug combination testing in our PDX models. By combining specific targeted drugs I hope to overcome de novo resistance mechanisms and prevent acquired resistance. Results from this study will guide future decisions about therapeutic strategies to improve survival of women with HGSEC. Citation Format: Holly E. Barker, Ratana Lim, Amandine Carmagnac, Cassandra Vandenberg, Gayanie Ratnayake, Genevieve Dall, Briony Milesi, Angela Komiti, Emily O'Grady, Joshua Tram, Kym Pham Stewart, Justin Bedo, Jocelyn Penington, Joep Vissers, Sean Grimmond, Matthew Wakefield, Tony Papenfuss, Clare Scott. Identifying effective combinations of targeted therapies, using novel pre-clinical models, to improve treatment options for high-grade serous endometrial cancer [abstract]. In: Proceedings of the AACR Virtual Special Conference: Endometrial Cancer: New Biology Driving Research and Treatment; 2020 Nov 9-10. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(3_Suppl):Abstract nr PO037.