Uterine Endometrioid Carcinoma Research Articles

Abstract B002: ARID1A loss activates MAPK signaling via DUSP4 downregulation: a mechanistic insight in endometrial carcinoma

Abstract The intricate interplay between chromatin remodelers, transcriptional regulation, and downstream cellular processes is gradually unraveling. AT-rich interactive domain-containing protein 1A (ARID1A), a tumor suppressor and chromatin remodeler, is frequently mutated in endometrium-related malignancies including ovarian or uterine clear cell carcinoma (CCC) and endometrioid carcinoma (EMCA). How ARID1A mutation alters downstream signaling is yet to be established. Based on the TCGA proteomics datasets, MAPK and ARID1A are negatively correlated in endometrial cancer. Yet, the underlying molecular mechanism of this association remains unclear. Using ARID1A-proficient and ARID1A-deficient isogenic human endometrial epithelial cells, we explored transcriptomic changes and discovered notable downregulation of a MAPK phosphatase, dual-specificity phosphatase 4 (DUSP4), in ARID1A-deficient cells. This expression pattern was further validated in additional pairs of isogenic cell lines, ES-2, MCF10a, and HCT116. Chromatin immunoprecipitation sequencing (ChIP-seq) was utilized to assess active and repressive transcription histone marks on global and 5’ transcriptional regulatory regions of DUSP4. ChIP-seq demonstrated decreased histone acetylation marks (H3K27Ac, H3K9Ac) on DUSP4 enhancer and promoter regions of ARID1A-deficient cells, suggesting ARID1A's role in modulating chromatin accessibility and gene expression. Furthermore, a positive correlation between ARID1A and DUSP4 expression was established using a Pax8-driven conditional knockout mouse cohort and in human endometroid carcinoma tissues. Moreover, an inverse expression correlation between ARID1A and the phosphatase substrates of DUSP4, including p-p38, p-JNK, and p-ERK in the MAPK signaling pathway, was observed in this genetically engineered murine model and in the TCGA datasets of human uterine carcinomas. Interestingly, ectopic DUSP4 expression decreased cell proliferation, and MAPK pathway targeting, specifically via ERK inhibitor Ulixertinib, significantly mitigated tumor growth in vivo. In conclusion, our findings suggest ARID1A modulates DUSP4 expression by remodeling the chromatin landscape which leads to an inhibitory effect on the MAPK pathway and suppresses tumor progression. ARID1A-DUSP4-MAPK axis offers a promising avenue for developing targeted therapies against ovarian or uterine CCC and EMCA. Citation Format: Jayaprakash Mandal, Zheng-Cheng Yu, Ie-Ming Shih, Tian-Li Wang. ARID1A loss activates MAPK signaling via DUSP4 downregulation: a mechanistic insight in endometrial carcinoma [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 B002.

Tumor Budding, Poorly Differentiated Clusters, and Stroma Percentage in Uterine Endometrioid Carcinomas Are Morphologic Findings Associated With Adverse Clinical Outcomes

Uterine endometrioid carcinoma (UEC) has well-defined morphologic features that carry prognostic significance and guide treatment. In addition to the well-known features, tumor budding (TB), poorly differentiated clusters (PDCs), and amount of stroma within the invasive front are associated with a poor prognostic outcome in many carcinomas. Here, we evaluate TB, PDCs, and the stroma percentage in UEC and correlate these findings with morphologic features known to be associated with a poor clinical outcome and with recurrence-free survival (RFS). We performed a retrospective search of our institution’s EMR for cases of hysterectomy for UEC. We collected clinical data including disease recurrence, death, and data associated with poor patient outcomes. Cases were evaluated for TB, PDCs, and percent stroma by 2 pathologists. Ten 20× fields were examined, and the one with the most PDCs and TB was evaluated. Percent stroma was evaluated in a ×10 field of tumor at the area of deepest invasion. Less than 10% stroma was defined as stroma poor, and >10% stroma was defined as stroma rich. Statistical testing and analysis were conducted, and P-value was set at 0.05. One hundred thirteen cases were evaluated. Decreased RFS was seen with TB (P=0.03), at least 5 PDCs (P=0.01), and stroma-rich tumors (P=0.043). This study shows a statistically significant association between TB presence, at least 5 PDCs, stroma-rich tumors, and decreased RFS in UEC. We conclude that TB, PDCs and stromal evaluation are strong independent prognostic indicators in UEC and provide additional value to the currently used morphologic assessment of UEC.

PD-L1 and PD-1 Expression in Early Stage Uterine Endometrioid Carcinoma.

Immune checkpoint inhibitors (ICI) and tumor-infiltrating lymphocytes (TILs) for cancer treatment in clinical oncology have revolutionized patient care. However, no gold standard exists for the criteria of analytical validity of TILs of different types of cancer. Clinicopathological data from 60 patients with endometrioid carcinoma (EC) who had undergone surgical treatment at the Gyeongsang National University Hospital between January 2002 and December 2009, were investigated. The programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PDL1) expression levels were characterized by immunohistochemical staining patterns, and the interpretations derived from machine learning morphometric analysis (Genie) and the pathologists' assessments were compared. In solid tumors, pathologists assessed the proportion of positive cells in each core of the tissue microarray. For Genie, the proportion of positive cells in the entire core and the number of positive cells per 1 mm2 were used. Both the pathologists and Genie identified the same trend in association with tumor size, with significant differences (p=0.026, p=0.033). Genie expression showed a significant association with PD1 expression, and pathologists identified a significant association with PDL1 expression in immune cells. The PD1 expression levels identified in immune cells of EC specimens were similar between the pathologists and Genie, suggesting that there is little resistance to the introduction of morphometric analysis. To our knowledge, this is the first study to introduce and validate machine learning as an integrated method for predicting prognosis and treatment based on PD1 expression in EC tumor microenvironments.

ARID1A loss activates MAPK signaling via DUSP4 downregulation

BackgroundARID1A, a tumor suppressor gene encoding BAF250, a protein participating in chromatin remodeling, is frequently mutated in endometrium-related malignancies, including ovarian or uterine clear cell carcinoma (CCC) and endometrioid carcinoma (EMCA). However, how ARID1A mutations alter downstream signaling to promote tumor development is yet to be established.MethodsWe used RNA-sequencing (RNA-seq) to explore transcriptomic changes in isogenic human endometrial epithelial cells after deleting ARID1A. Chromatin immunoprecipitation sequencing (ChIP-seq) was employed to assess the active or repressive histone marks on DUSP4 promoter and regulatory regions. We validated our findings using genetically engineered murine endometroid carcinoma models, human endometroid carcinoma tissues, and in silico approaches.ResultsRNA-seq revealed the downregulation of the MAPK phosphatase dual-specificity phosphatase 4 (DUSP4) in ARID1A-deficient cells. ChIP-seq demonstrated decreased histone acetylation marks (H3K27Ac, H3K9Ac) on DUSP4 regulatory regions as one of the causes for DUSP4 downregulation in ARID1A-deficient cells. Ectopic DUSP4 expression decreased cell proliferation, and pharmacologically inhibiting the MAPK pathway significantly mitigated tumor formation in vivo.ConclusionsOur findings suggest that ARID1A protein transcriptionally modulates DUSP4 expression by remodeling chromatin, subsequently inactivating the MAPK pathway, leading to tumor suppression. The ARID1A-DUSP4-MAPK axis may be further considered for developing targeted therapies against ARID1A-mutated cancers.

Comparison of clinical characteristics and prognosis in endometrial carcinoma with different pathological types: a retrospective population-based study

BackgroundEndometrial carcinoma (EC) is the second most common gynecological malignancy, and the differences between different pathological types are not entirely clear. Here, we retrospectively collected eligible EC patients to explore their differences regarding clinical characteristics and prognosis.MethodsFive hundred seventy EC patients from the First Affiliated Hospital of Zhengzhou University were included. Prognostic factors were measured using the univariate/multivariate Cox models. Overall survival (OS) and progression-free survival (PFS) were the primary and secondary endpoints, respectively.ResultsIn total, 396 patients with uterine endometrioid carcinoma (UEC), 106 patients with uterine serous carcinoma (USC), 34 patients with uterine mixed carcinoma (UMC), and 34 patients with uterine clear cell carcinoma (UCCC) were included. Comparison of baseline characteristics revealed patients diagnosed with UEC were younger, had more early clinical stage, and had lower incidence of menopause and lymph node metastasis. Compared to UEC, other pathological EC obtained more unfavorable OS (UCCC: HR = 12.944, 95%CI = 4.231–39.599, P < 0.001; USC: HR = 5.958, 95%CI = 2.404–14.765, P < 0.001; UMC: HR = 1.777, 95%CI = 0.209–15.114, P = 0.599) and PFS (UCCC: HR = 8.696, 95%CI = 1.972–38.354, P = 0.004; USC: HR = 4.131, 95%CI = 1.243–13.729, P = 0.021; UMC: HR = 5.356, 95%CI = 0.935–30.692, P = 0.060). Compared with UEC patients, the OS of UCCC patients in stage I–II and USC patients in stage III–IV were significantly worse, while UMC patients in stage I–II favored poorer PFS. The OS of UCCC patients receiving no postoperative adjuvant therapy or chemotherapy alone were significantly worse.ConclusionsThe baseline characteristics of UEC and other rare EC types varied greatly, and the prognostic significance of different pathological types on EC patients depended on clinical tumor stages and therapeutic options.

Effects of radiotherapy on the survival of patients with stage IA and low-grade stage IB uterine endometrioid carcinoma

The present study aimed to evaluate the effects of radiotherapy on the overall survival of patients with primary stage IA, grade I–III uterine endometrioid carcinoma or stage IB, grade I–II uterine endometrioid carcinoma. A total of 7504 patients with stage IA, grade I–III uterine endometrioid carcinoma, and 857 patients with stage IB, grade I–II uterine endometrioid carcinoma were collected for the present study. Following propensity score matching (PSM), statistical analysis was performed for the equalized number of patients with stage IA, grade I–III uterine endometrioid carcinoma (n = 383) and patients with stage IB, grade I–II uterine endometrioid carcinoma (n = 330). For patients with primary stage IA, grade I–III uterine endometrioid carcinoma, radiotherapy was found to promoted a reduced 5-year overall survival rates [hazard ratio (HR), 1.726; 95% confidence interval (CI), 1.456–2.046; P < 0.05]. In patients with primary stage IB, grade I–II uterine endometrioid carcinoma, no significant differences were observed in the 5-year overall survival rates between radiotherapy and no radiotherapy groups (P = 0.059). In conclusion, radiotherapy may not improve 5-year overall survival for patients with primary stage IA, grade I–III or stage IB, grade I–II uterine endometrioid carcinoma.

Applicability of the FDA-approved Immunohistochemical Panel for Identification of MMRd Phenotype in Uterine Endometrioid Carcinoma.

Recently, the US Food and Drug Administration (FDA) approved the Ventana MMR RxDx Panel as the first immunohistochemical companion diagnostic test for identification of tumors with mismatch repair (MMR) status. The aim of this study was to investigate the accuracy of this test in comparison with polymerase chain reaction (PCR)-based microsatellite instability (MSI) analysis. We assessed the MMR/MSI concordance rate in 140 cases of endometrioid carcinoma. MMR status was evaluated by immunohistochemistry (MMR-IHC), and MSI status was evaluated by PCR-based analysis (MSI-PCR). Potential molecular mechanisms responsible for MSH6 staining variations were also analyzed. Immunohistochemistry showed that 34 tumors (24.3%) were MMRd; these included 26 with combined MLH1/PMS2 loss, 2 with combined MSH2/MSH6 loss, and 6 with isolated MSH6 loss. Heterogeneous MSH6 loss was found in 10 tumors and was recognized only in tumors with combined MLH1/PMS2 loss. Eight of 10 tumors with heterogeneous MSH6 loss harbored MSH6 C8 tract instability, suggesting a secondary somatic event after MLH1/PMS2 loss. MSI-PCR revealed that 102 tumors were MSS, 4 were MSI-low, and 34 were MSI-high. Consequently, MMR-IHC and MSI-PCR showed perfect concordance (kappa=0.080, P <0.0001). However, 10 of the 34 MSI-high tumors, including the 6 tumors with isolated MSH6 loss, showed only minimal microsatellite shift by MSI-PCR, which may have been erroneously interpreted as MSS or MSI-low. On the basis of these findings, we consider that the FDA-approved immunohistochemical panel can detect MMR variations consistently and is more accurate than MSI-PCR for determining the applicability of immune checkpoint inhibitors for treatment of endometrioid carcinomas.

The Prognostic Impact of Substantial Lymphovascular Space Invasion in Women with FIGO Stage I Uterine Endometrioid Carcinoma with Pathologically Negative Nodal Evaluation

Substantiallymphovascular space invasion (LVSI) is an important predictor of lymph node involvement in women with endometrial carcinoma. However, its prognostic significance in women with stage I who had pathologic negative nodal evaluation (PNNE) was not fully evaluated. We aimed to evaluate the prognostic significance of substantial LVSI on recurrence-free (RFS), disease-specific (DSS) and overall survival (OS) in women with FIGO stage I uterine endometrioid adenocarcinoma (EC). Our uterine cancer database was queried for women with stage I EC who had a hysterectomy and PNNE at our institution between 1/1990 and 11/2022. Postoperatively, patients were managed with observation or adjuvant radiation therapy (RT) with pelvic external beam RT or vaginal cuff brachytherapy (VB). Women with synchronous malignancies and those who received adjuvant chemotherapy were excluded. Pathologic specimens were retrieved and LVSI was quantified by Gynecology pathologists (none, focal or substantial). Patients' demographics, surgical and pathologic variables were analyzed. Predictors of RFS, DSS and OS using univariate (UVA) and multivariate analysis (MVA) were studied. One thousand fifty-two patients were identified with a median age of 63 years and median follow-up of 9.7 years. Median number of examined lymph node (LN) were 9 (range 4-18). 907 patients (86.2%) had no LVSI, 87 (8.3%) had focal and 58 (5.5%) had substantial LVSI. In patients with focal LVSI, 32.2% received pelvic RT and 39.1% received VB. In patients with substantial LVSI, 20.7% received pelvic RT and 58.6% received VB.Recurrence was diagnosed in 86 patients (8.2%). While any LVSI was associated with tumor recurrence, there was no significant difference for the site of initial recurrence between patients with focal vs. substantial LVSI. 5-year RFS was 93.3% (95% CI 91.5-95.1), 76.8% (67.2-87.7) and 79.1% (67.6-95.3) for no, focal and substantial LVSI. The 5-year DSS was 97.6% (96.5-98.7), 83.5% (75-93.1), and 90% (81.8-99.9); and 5-year OS was 90.7% (88.7-92.8), 72.8% (62.9-84.2) and 86% (76.2-97.2), respectively. Independent predictors of worse 5-year RFS and DSS include any LVSI, age > 60 years, higher tumor grade. Independent predictors of worse 5- year OS include any LVSI, age > 60, high comorbidity burden, and higher tumor grade. Our large data suggest similar recurrence-free, disease specific and OS for women with stage I uterine endometrioid carcinoma who had pathologically negative nodal evaluation and substantial or focal LVSI. There was no significant difference for the site of initial recurrence between patients with focal or substantial LVSI. Multi-institutional pooled analyses may be needed to validate our results.

Clinicopathological correlations of endometrioid and clear cell carcinomas in the uterus and ovary.

Endometrioid carcinoma (EC) and clear cell carcinoma (CC) are associated with endometrial tissue hyperplasia and endometriosis, and they occur in the endometrium and ovaries. However, detailed differences between these tumors based on immunostaining are unclear; therefore, in this study, we aimed to analyze the clinicopathological correlations between these tumors using immunostaining and to develop new treatments based on histological subtypes. Immunohistochemistry was used to investigate differentially expressed hypoxia-associated molecules (hypoxia-inducible factor-1 subunit alpha [HIF-1α], forkhead box O1, prostate-specific membrane antigen, signal transducer and activator of transcription 3 [STAT3], hepatocyte nuclear factor 1β [HNF-1β], aquaporin-3, and vimentin [VIM]) between these carcinomas because of the reported association between CC and ischemia. Immunostaining and clinicopathological data from 70 patients (21 uterine endometrioid carcinomas [UECs], 9 uterine cell carcinomas, 20 ovarian endometrioid carcinomas [OECs], and 20 ovarian cell carcinomas [OCCs]) were compared. HIF-1α and prostate-specific membrane antigen expression levels were higher in UEC and OCC than in uterine cell carcinomas and OEC. STAT3 was slightly overexpressed in UEC. Additionally, forkhead box O1 expression was either absent or significantly attenuated in all ECs. VIM and AQ3 were highly expressed in UEC, whereas HNF-1β expression was higher in OCC. UEC, OEC, and OCC were more common in the uterine fundus, left ovary, and right ovary, respectively. Ovarian endometriosis was strongly associated with EC. Our findings suggest that UEC and OCC share a carcinogenic pathway that involves HIF-1α induction under hypoxic conditions via STAT3 expression, resulting in angiogenesis. Furthermore, the anatomical position of carcinomas may contribute to their carcinogenesis. Finally, aquaporin-3 and VIM demonstrate strong potential as biomarkers for UEC, whereas HNF-1β expression is a crucial factor in CC development. These differences in tumor site and histological subtypes shown in this study will lead to the establishment of treatment based on histological and immunohistological classification.

Recurrence Risk Stratification for Women With FIGO Stage I Uterine Endometrioid Carcinoma Who Underwent Surgical Lymph Node Evaluation.

The aim of this study was to estimate the recurrence risk based on the number of prognostic factors for patients with stage I uterine endometrioid carcinoma (EC) who underwent surgical lymph node evaluation (SLNE) and were managed with observation. We queried our database for women with FIGO-2009 stage I EC who underwent surgical staging including SLNE. Multivariate analysis with stepwise model selection was used to determine independent risk factors for 5-year recurrence-free survival (RFS). Study groups based on risk factors were compared for RFS, disease-specific survival, and overall survival. A total of 706 patients were identified: median age was 60 years (range, 30 to 93y) and median follow-up was 120 months. Median number of examined lymph nodes was 8 (range, 1 to 66). 91% were stage IA, 75% had grade 1 and lymphovascular space invasion was detected in 6%. Independent predictors of 5-year RFS included age 60 years and above ( P =0.038), grade 2 ( P =0.003), and grade 3 ( P <0.001) versus grade 1. Five-year RFS for group 0 (age less than 60y and grade 1) was 98% versus 92% for group 1 (either: age 60y and older or grade 2/3) versus 84% for group 2 (both: age 60y and above and grade 2/3), respectively ( P <0.001). Five-year disease-specific survival was 100% versus 98% versus 95%, ( P =0.012) and 5-year overall survival was 98% versus 90% versus 81%, for groups 0, 1, and 2, respectively ( P <0.001). In patients with stage I EC who received SLNE and no adjuvant therapy, only age 60 years and above and high tumor grade were independent predictors of recurrence and can be used to quantify individualized recurrence risk, whereas lymphovascular space invasion was not an independent prognostic factor in this cohort.

The Prognostic Significance of the Depth of Cervical Stromal Invasion in Women With FIGO Stage II Uterine Endometrioid Carcinoma.

The objective of this study was to investigate the prognostic significance of the depth of cervical stromal invasion (CSI) in women with FIGO stage II uterine endometrioid adenocarcinoma (EC). Our database of women with EC was quired for patients with stage II EC. Pathologic slides were retrieved and reviewed by gynecologic pathologists to determine cervical stromal thickness and depth of CSI as a percentage of stromal thickness (%CSI). Kaplan-Meier, univariate, and multivariate analyses were used to compare recurrence-free, disease-specific (DSS), and overall survival (OS) between women who had<50% versus ≥50% CSI. Univariate and multivariate analyses were used to assess other prognostic variables associated with survival endpoints. A total of 117 patients were included in our study who had hysterectomy between 1/1990 and 8/2021. Seventy-nine patients (68%) with <50% and 38 (32w%) with ≥50% CSI. After a median follow-up of 131 months, 5-year DSS was significantly worse for women with ≥50% CSI (78% vs. 91%; P =0.04). However, %CSI was not an independent predictor for any of the studied survival endpoints. Independent predictors of worse 5-year recurrence-free survival and DSS included FIGO grade 3 tumors ( P =0.02) and the presence of lymphovascular space invasion ( P =0.03). Grade 3 tumors were the only independent predictor of worse 5-year OS ( P =0.02). Our results suggest that deep CSI is not an independent prognostic factor for survival endpoints in women with stage II uterine endometroid adenocarcinoma. The lack of independent prognostic significance of the depth CSI needs to be validated in a multi-institutional analysis.

CXCL9 correlates with antitumor immunity and is predictive of a favorable prognosis in uterine corpus endometrial carcinoma.

The C-X-C motif chemokine ligand-9 (CXCL9) is related to the progression of multiple neoplasms. Yet, its biological functions in uterine corpus endometrioid carcinoma (UCEC) remain shrouded in confusion. Here, we assessed the prognostic significance and potential mechanism of CXCL9 in UCEC. Firstly, bioinformatics analysis of the public cancer database, including the Cancer Genome Atlas / the Genotype-Tissue Expression project (TCGA+ GTEx, n=552) and Gene Expression Omnibus (GEO): GSE63678 (n=7), were utilized for the CXCL9 expression-related analysis in UCEC. Then, the survival analysis of TCGA-UCEC was performed. Futher, the gene set enrichment analysis (GSEA) was carried out to reveal the potential molecular signaling pathway in UCEC associated with CXCL9 expression. Moreover, the immunohistochemistry (IHC) assay of our validation cohort (n=124) from human specimens were used to demonstrate the latent significance of CXCL9 in UCEC. The bioinformatics analysis suggested that CXCL9 expression was significantly upregulated in UCEC patients; and hyper-expression of CXCL9 was related to prolonged survival. the GSEA enrichment analysis showed various immune response-related pathways, including T/NK cell, lymphocyte activation, cytokine-cytokine receptor interaction network, and chemokine signaling pathway, mediated by CXCL9. In addition, the cytotoxic molecules (IFNG, SLAMF7, JCHAIN, NKG7, GBP5, LYZ, GZMA, GZMB, and TNF3F9) and the immunosuppressive genes (including PD-L1) were positively related to the expression of CXCL9. Further, the IHC assay indicated that the CXCL9 protein expression was mainly located in intertumoral and significantly upregulated in the UCEC patients; UCEC with high intertumoral CXCL9 cell abundance harbored an improved prognosis; a higher ratio of anti-tumor immune cells (CD4+, CD8+, and CD56+ cell) and PD-L1 was found in UCEC with CXCL9 high expression. Overexpressed CXCL9 correlates with antitumor immunity and is predictive of a favorable prognosis in UCEC. It hinted that CXCL9 may serve as an independent prognostic biomarker or therapeutic target in UCEC patients, which augmented anti-tumor immune effects to furnish survival benefits.

Recurrence Risk Stratification for Women with FIGO Stage I Uterine Endometrioid Carcinoma Who Underwent Surgical Lymph Node Evaluation

<h3>Purpose/Objective(s)</h3> To estimate the recurrence risk based on the number of prognostic factors in women with FIGO stage I uterine endometrioid carcinoma (EC) in a large cohort of patients who underwent surgical staging including surgical lymph node evaluation (SLNE) and were managed with no adjuvant therapy. <h3>Materials/Methods</h3> We queried our in-house prospectively maintained uterine cancer database for patients with FIGO stage I EC underwent surgical staging including SLNE between 1/1990-12/2020. Patients with synchronous ovarian and breast cancer diagnosis were excluded as well as those who received adjuvant therapy of any form. Patient's demographics and pathologic variables were analyzed. We used multivariate analysis (MVA) with Stepwise Model Selection to determine risk factors for 5-year recurrence-free survival (RFS). Study population was then stratified based on the number of risk factors identified (0, 1 or 2). The resultant groups were compared for RFS, disease-specific survival (DSS) and overall survival (OS) using log-rank test and Kaplan-Meier curves. Additionally, independent predictors of DSS and overall OS were estimated. <h3>Results</h3> 706 patients were identified who met our inclusion criteria with a median age of 60 years (range, 30-93) and a median follow-up of 120 months. All patients had at least pelvic SLNE with a median number of examined lymph node (LN) of 8 (range, 1-66): 66 patients (11%) had a sentinel LN sampling and 43% had paraaortic SLNE. 639 patients (91%) were stage IA and lymphovascular space invasion (LVSI) was detected in 6% (n=41). Recurrence was diagnosed in 44 patients (6%). Independent predictors of 5-year RFS include age ≥ 60 years (<i>p</i>=0.038), grade 2 vs. 1 (<i>p</i>=0.003), and grade 3 vs 1 (<i>p</i><0.001). 5-year RFS for group-0 (age < 60 years and grade 1) was 98% vs. 92% for group-1 (either: age ≥ 60 years or grade 2/3) vs 84% for group-2 (both: age ≥ 60 years and grade 2/3), respectively (<i>p</i><0.001). 5- year DSS for the three groups was (100% vs 98% vs 95%, <i>p</i>=0.012) and 5-year OS was (98% vs 90% vs 81%, <i>p</i><0.001), respectively. On MVA, stage IB vs IA was deterministic for DSS (<i>p</i>=0.02); whereas age ≥ 60 years (p<0.001) and grade 3 vs grade 1 (<i>p</i>=0.004) were predictors for worse OS. <h3>Conclusion</h3> In patients with stage I endometrioid carcinoma who had surgical staging including SLNE and no adjuvant therapy, only age ≥ 60 years and high tumor grade were independent predictors of cancer recurrence and hence can be used to quantify individualized recurrence risk. Surprisingly, LVSI was not an independent prognostic factor in this study cohort with SLNE.

The Prognostic Significance of the Depth of Cervical Stromal Invasion in Women with FIGO Stage II Uterine Endometrioid Carcinoma

<h3>Purpose/Objective(s)</h3> To explore the prognostic significance of the depth of cervical stromal invasion (CSI) on survival endpoints in women with FIGO stage II uterine endometrioid adenocarcinoma. <h3>Materials/Methods</h3> A total of 117 patients were included in this retrospective review. Between 1990 and 2021, all patients with FIGO stage II endometrial cancer (EC) underwent hysterectomy and oophorectomy at our institution, with or without lymph node dissection. Patients with synchronous ovarian or breast cancer, as well as those who had undergone adjuvant systemic chemotherapy for EC, were excluded from the study. Pathologic slides were retrieved for these patients and were reviewed by a gynecologic pathologist to determine stromal thickness and the depth of CSI. The depth of CSI was then measured as a percentage of invasion (% CSI) and used in the analysis as a continuous or dichotomous variable (< 50% vs > = 50%). Patients' demographics, pathologic, and treatment characteristics were analyzed using univariate and multivariate analysis to calculate recurrence-free (RFS) and disease-specific (DSS) rates. <h3>Results</h3> The median age for the study cohort was 65 years (range, 34–96), and the median follow-up was 131 months (range, 9–334). A total of 90 patients (77%) had lymph node dissection, with a median of 8 examined lymph nodes (range 0-18). Adjuvant radiation therapy (RT) with pelvic or vaginal cuff HDR brachytherapy, or a combination of the two, was completed in 92 patients (79 percent). The median % CSI was 27% (range, 1-100) with 68% of patients having ≥ 50% CSI. While there was a trend for a worse 5-year RFS and DSS for women with ≥ 50% CSI (69% vs. 83%, p = 0.093) and (78% vs. 91%, p = 0.034), respectively, the depth of CSI was not statistically significant as an independent predictor of 5-year RFS, DSS, or OS. The depth of CSI was not associated with a difference in the recurrence pattern (vaginal cuff, pelvic, paraaortic, or distant). In multivariate analysis, FIGO grade was the only predictor of 5-year OS. FIGO grade and the presence of lympho-vascular space invasion (LVSI) were independent predictors of 5-year RFS and DSS. <h3>Conclusion</h3> Deep cervical stromal invasion does not appear to be an independent predictive factor for survival endpoints in women with stage II uterine endometroid cancer, according to our findings. The presence of LVSI and tumor grade were both independent predictors of recurrence-free and disease-specific survival. Pooled data analysis may be needed to validate our study findings.

Comprehensive Approach to Genomic and Immune Profiling: Insights of a Real-World Experience in Gynecological Tumors.

Gynecological cancer accounts for an elevated incidence worldwide requiring responsiveness regarding its care. The comprehensive genomic approach agrees with the classification of certain tumor types. We evaluated 49 patients with gynecological tumors undergoing high-throughput sequencing to explore whether identifying alterations in cancer-associated genes could characterize concrete histological subtypes. We performed immune examination and analyzed subsequent clinical impact. We found 220 genomic aberrations mostly distributed as single nucleotide variants (SNV, 77%). Only 3% were classified as variants of strong clinical significance in BRCA1 and BRCA2 of ovarian high-grade serous (HGSC) and uterine endometrioid carcinoma. TP53 and BRCA1 occurred in 72% and 28% of HGSC. Cervical squamous cell carcinoma was entirely HPV-associated and mutations occurred in PIK3CA (60%), as well as in uterine serous carcinoma (80%). Alterations were seen in PTEN (71%) and PIK3CA (60%) of uterine endometrioid carcinoma. Elevated programmed death-ligand 1 (PD-L1) was associated with high TILs. Either PD-L1 augmented in deficient mis-matched repair (MMR) proteins or POLE mutated cases when compared to a proficient MMR state. An 18% received genotype-guided therapy and a 4% immunotherapy. The description of tumor subtypes is plausible through high-throughput sequencing by recognizing clinically relevant alterations. Additional concomitant assessment of immune biomarkers identifies candidates for immunotherapy.

Addition of External Beam Radiation Therapy to Adjuvant Chemotherapy for Patients With Stage IIIC Uterine Endometrioid Carcinoma: Utilization and Outcomes.

Evaluate whether the addition of external beam radiation (EBRT) to adjuvant chemotherapy with or without vaginal brachytherapy is associated with better survival for patients with stage IIIC endometrioid endometrial carcinoma. Patients diagnosed between 2010 and 2015 with apparent early-stage endometrioid adenocarcinoma, without a history of another tumor, who underwent hysterectomy with lymphadenectomy and had positive lymph nodes were identified in the National Cancer Database. Those who received adjuvant chemotherapy (defined as receipt of treatment within 6mo from surgery) and had at least 1 month of follow-up were selected for further analysis. Overall survival was compared between patients who did and did not receive EBRT within 6 months from surgery with the log-rank test. A Cox model was also constructed to control for confounders. A total of 3116 patients were identified; 1458 (46.8%) received chemotherapy without and 1658 (53.2%) with EBRT. Pathologic characteristics (tumor grade, size, endocervical, and lymph-vascular invasion) were comparable between the two groups. Patients who received external beam radiation had better survival compared with those who did not, P =0.001; 5-year overall survival rates were 83.1% and 77.9%, respectively. After controlling for patient age, race, presence of comorbidities, insurance status, tumor size, grade and endocervical invasion, and the presence of lymph-vascular invasion, the addition of EBRT was associated with a survival benefit (HR: 0.75, 95% CI: 0.62, 0.91). For patients with endometrioid adenocarcinoma metastatic to the lymph nodes, addition of external beam radiation to adjuvant chemotherapy may be associated with a survival benefit.

Coexistence of malignant ovarian Brenner tumor and borderline mucinous cystadenoma, combined with primary uterine corpus endometrioid carcinoma: A case report and literature review.

Malignant Brenner tumor (MBT) of the ovary is a rare malignant ovarian tumor, whereas uterine corpus endometrioid carcinoma (UEC) constitutes one of the most common malignant tumors of the female reproductive system. The present study reported on a case of the coexistence of ovarian MBT and borderline mucinous cystadenoma combined with primary UEC. Therefore, the present case is a synchronous primary cancer of both ovary and endometrium. Although synchronous primary cancers of the endometrium and ovary are relatively uncommon, they are not rare; however, due to the rarity of MBT, this case was considered singular. To the best of our knowledge, this was the first-ever reported case of the coexistence of an ovarian MBT and borderline mucinous cystadenoma combined with primary UEC. Based on a review of the literature associated with the present case, its clinicopathological features, immunohistochemical phenotype, differential diagnosis, molecular changes, prognosis and treatment were summarized and discussed. The aim of the present study was to improve the understanding of this rare synchronous primary cancer of the ovary and endometrium so as to avoid future misdiagnosis.

Abstract 80: Genomic characterization of PDX models from rare cancer patients in the NCI Patient-Derived Models Repository

Abstract Background: The National Cancer Institute’s Patient-Derived Models Repository (NCI PDMR; https://pdmr.cancer.gov) has developed a large number of patient-derived xenograft (PDX) models from a diverse set of rare cancers. These models have been genomically characterized using whole-exome sequencing (WES) and RNAseq. The resource provides a unique opportunity to explore the genomic features of rare tumor models in NCI PDMR and to understand the oncogenic processes in pre-clinical models to identify biomarkers associated with therapeutic responses. Methods: Genomic characterization was done in 4-6 PDX samples across multiple passages and lineages from each model. As the samples exhibited a high level of genomic stability within each model, consensus mutation and copy number variation (CNV), microsatellite instability (MSI), genomic loss of heterozygosity (LOH), homologous recombination deficiency score (scarHRD), and mutational signature data were generated from WES. Fusions were identified from RNASeq data using Star-Fusion and FusionInspector. Gene set enrichment analysis was conducted from the gene expression data obtained from RNAseq. Results: 1) 233 PDX models have been developed and characterized from more than 45 different rare malignancies. Most frequent cancer types are different sarcomas (n=63), head &amp; neck squamous cell carcinoma (n=61), and malignant fibrous histiocytoma (MFH) (n=11); 2) TP53 was the most frequently altered gene, mutated in 51% of models, followed by NOTCH1 (16%) and PIK3CA (11%). In terms of CNVs, ovarian epithelial cancer (OVT) showed relatively high chromosomal instability, while uterine endometrioid carcinoma (UEC) and synovial sarcoma (SYNS) had low instability; 3) MSI-H was observed in only 7 models. Esophageal adenocarcinoma (ESCA), OVT, and cervical squamous cell carcinoma (CESC) had high scarHRD and genomic LOH scores, while both scores were low in UEC and anal squamous cell carcinoma (ANSC). COSMIC v2 mutational signature 3 is significantly associated with a high scarHRD score (p-value &amp;lt; 0.01, Wilcoxon rank-sum test); 4) Characteristic fusions were observed in certain sarcoma models: SS18-SSX1 and ASPSCR1-TFE3 fusions were observed in SYNS and alveolar soft part sarcoma (ASPS) models respectively. EWSR1-FLI1 fusion was present in 2 out of 3 Ewing sarcoma (ES) models. 5) Gene set enrichment analysis from RNASeq data showed that epithelial-mesenchymal transition score could accurately distinguish carcinoma from sarcoma models, confirming the divergent gene expression programs. Conclusion: Comprehensive genomic characterization of NCI PDMR models generated from rare cancers solves an unmet need in the community. It will serve as a valuable resource for translational researchers interested in pre-clinical drug development and discovery. Citation Format: Li Chen, Rini Pauly, Ting-Chia Chang, Biswajit Das, Yvonne A. Evrard, Chris A. Karlovich, Tomas Vilimas, Alyssa Chapman, Nikitha Nair, Luis Romero, Anna Lee Fong, Amanda Peach, Shahanawaz Jiwani, Nastaran Neishaboori, Lindsay Dutko, Kelly Benauer, Gloryvee Rivera, Erin Cantu, Corinne Camalier, Thomas Forbes, Michelle Gottholm-Ahalt, John Carter, Suzanne Borgel, Chelsea McGlynn, Candace Mallow, Emily Delaney, Tiffanie Miner, Michelle A. Eugeni, Dianne Newton, Melinda G. Hollingshead, P. Mickey Williams, James H. Doroshow. Genomic characterization of PDX models from rare cancer patients in the NCI Patient-Derived Models Repository [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 80.

Abstract 3361: Distinct biological response of uterine corpus serous and endometrioid carcinomas to obesity may contribute to differences in clinical outcomes

Abstract Despite growing evidence linking obesity to the development and overall survival of cancer patients, the impact of increased body mass index (BMI) on gene expression patterns in gynecologic cancers is unclear. To address this, we herein downloaded RNAseq gene expression data from The Cancer Genome Atlas (TCGA) UCEC (uterine corpus endometrial carcinoma) dataset and matched it with clinical data entries including patient height and weight. We calculated BMI for each patient and used it to stratify patients as normoweight (BMI &amp;lt; 25), overweight (25 ≤ BMI &amp;lt; 30) or obese (BMI ≥ 30). BMI and nutritional status were matched to RNAseq gene expression data. Considering the known differences between endometrioid and serous uterine corpus tumors, analyses were performed separately for endometrioid (n = 356) and serous carcinomas (n = 117). Gene set enrichment analysis (GSEA) was performed between normoweight, overweight and obese patients. GSEA shows that tumors from obese patients display multiple dysregulated Gene Ontology (GO) terms (Biological Process, BP), which also differ between serous and endometrioid tumors. We further explored the impact of obesity on transcriptomic profiles of serous and endometrioid carcinomas by nutritional status independently by differential expression analysis using limma-voom. Significantly up- or downregulated genes were defined as those with logFC ≥ 1.5 at a non-adjusted P-value ≤ 0.01. Despite a clear enrichment or suppression of GO terms as evidenced by GSEA, transcriptomic analyses did not clearly separate patients according to their nutritional status. Therefore, obesity may impact on the dysregulation of biological processes through the cumulative effects of subtle differences in gene expression that, individually, do not seem to play a major role in oncogenesis. These results spotlight the relevance of obesity on the biology of uterine corpus cancers, which impact on the clinical course and treatment response of obese patients is yet to be determined. Funding: This work was supported by CONICYT FONDAP 15130011 (MC, IW), CONICYT-PFCHA/Doctorado Nacional 2019-Folio 21190421 (FG) and FONDECYT 1201083 (MC). Citation Format: Ignacio A. Wichmann, Fernán Gómez, Cristián Salazar, Felipe Suárez, Sumie Kato, Mauricio A. Cuello-Fredes. Distinct biological response of uterine corpus serous and endometrioid carcinomas to obesity may contribute to differences in clinical outcomes [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 3361.

Abstract 3341: Synthetic lethality by targeting ribonucleotide reductase in PP2A deficient uterine serous carcinoma

Abstract Uterine serous carcinoma (USC) is a highly aggressive endometrial cancer subtype with limited therapeutic options and a lack of targeted therapies. While mutations to PPP2R1A, encoding the predominant protein phosphatase 2A (PP2A) scaffolding protein Aα, occur in 30-40% of cases, the clinical actionability of these mutations has not been studied. Here, we show that mutation to Aα results in synthetic lethality to treatment with inhibitors of ribonucleotide reductase (RNR), and multiple models of Aα mutant uterine serous tumors were sensitive to Clofarabine, an RNR inhibitor in vivo. Aα mutant cells displayed impaired checkpoint signaling upon RNRi treatment, and subsequently accumulated more DNA damage than wild type cells. This was PP2A dependent as complete inhibition of PP2A activity using LB-100, a catalytic site inhibitor, sensitized wild type USC cells to RNRi. Analysis of TCGA data indicated that inactivation of PP2A, through loss of PP2A subunit expression, was prevalent in USC, with 88% of USC patients harboring loss of at least one PP2A gene. In contrast, loss of PP2A subunit expression was rare in uterine endometrioid carcinomas. While RNR inhibitors are not routinely used for uterine cancers, we identified a cohort of patients with recurrent disease treated with gemcitabine at MSKCC as a second or later line therapy. In a retrospective analysis of this cohort there was a trend for improved outcomes in USC patients treated with RNRi gemcitabine compared to patients with endometrioid histology. Overall, our data provide experimental evidence to support the use of ribonucleotide reductase inhibitors for the treatment of USC. Citation Format: Caitlin M. O'Connor, Sarah E. Taylor, Kathryn M. Miller, Lauren Hurst, Terrance J. Haanen, Tahra K. Suhan, Kaitlin P. Zawacki, Fallon K. Noto, Jonida Trako, Arathi Mohan, Jaya Sangodkar, Dmitriy Zamarin, Analisa DiFeo, Goutham Narla. Synthetic lethality by targeting ribonucleotide reductase in PP2A deficient uterine serous carcinoma [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 3341.