Endometrioid Research Articles

Rare Germline Genetic Variants and the Risks of Epithelial Ovarian Cancer.

Simple SummarySeveral genes have been confirmed as risk genes for epithelial ovarian cancer (EOC). There are five main types of EOC, with different molecular changes and clinical characteristics, suggesting they should be considered different diseases. This review summarises the contribution of rare inherited mutations to EOC susceptibility, focussing on the frequency in each EOC type. Susceptibility genes can have a major clinical impact, reducing ovarian cancer incidence by screening of family members to detect women at higher risk than the general population. They can also lead to the development of new targeted treatments.A family history of ovarian or breast cancer is the strongest risk factor for epithelial ovarian cancer (EOC). Germline deleterious variants in the BRCA1 and BRCA2 genes confer EOC risks by age 80, of 44% and 17% respectively. The mismatch repair genes, particularly MSH2 and MSH6, are also EOC susceptibility genes. Several other DNA repair genes, BRIP1, RAD51C, RAD51D, and PALB2, have been identified as moderate risk EOC genes. EOC has five main histotypes; high-grade serous (HGS), low-grade serous (LGS), clear cell (CCC), endometrioid (END), and mucinous (MUC). This review examines the current understanding of the contribution of rare genetic variants to EOC, focussing on providing frequency data for each histotype. We provide an overview of frequency and risk for pathogenic variants in the known susceptibility genes as well as other proposed genes. We also describe the progress to-date to understand the role of missense variants and the different breast and ovarian cancer risks for each gene. Identification of susceptibility genes have clinical impact by reducing disease-associated mortality through improving risk prediction, with the possibility of prevention strategies, and developing new targeted treatments and these clinical implications are also discussed.

Abstract B37: Germline mutations in new susceptibility genes for non-high-grade serous ovarian cancer

Abstract Improving risk prediction and prevention strategies through identifying new susceptibility genes for non-high-grade serous ovarian cancer (non-HGS) would represent an important advance in reducing incidence and mortality. Epithelial ovarian cancer (EOC) has five main histotypes that have distinct pathologies, molecular changes, clinical characteristics, and tissues of origin. They are classified as high-grade serous (HGS), low-grade serous (LGS), clear-cell (CCC), endometrioid (END), and mucinous (MUC). A family history of breast or ovarian cancer is the strongest single risk factor for EOC. Germline mutations in the high-penetrance susceptibility genes BRCA1 and BRCA2 confer EOC risks of 44% and 17% by age 80, respectively. Only 40% of the excess familial risk is known, suggesting there are many other susceptibility genes yet unidentified. The non-HGS histotypes are poorly studied due to limited sample size within individual studies. Thus, families of cases with non-HGS tumors have few risk prediction options. Whole-exome sequencing (WES) analysis was performed on 251 non-HGS cases (56 LGS, 55 CCC, 117 END, 23 MUC). Cases were screened negative for BRCA1/2 mutations and selected for a family history of ovarian or breast cancer, or young onset (<45 years) of ovarian cancer. WES identified 1,278 genes with rare predicted truncating mutation in at least one case. Predicted truncating mutations in cases were compared to 171,584 controls from the Exome Aggregation Consortium (ExAC) and the Genome Aggregation Database (gnomAD). Gene-set enrichment analysis showed enrichment for genes involved in the DNA repair pathway (p=3.08 × 10−7). Twenty-five candidate genes (including 4 DNA repair genes) were selected for validation by targeted sequencing. Five genes important in HGS (BRIP1, FANCM, PALB2, RAD51C, RAD51D) as well as two additional candidates (XRCC2 and XRCC3) were also sequenced. Targeted sequencing was performed on 1,779 cases (669 END, 356 CCC, 327 LGS, 427 MUC) and 1,863 controls from studies in the Ovarian Cancer Association Consortium (OCAC). Library preparation and target enrichment was performed using the Fluidigm Juno System and Illumina sequencing was performed on a NovaSeq 6000 Sequencing System. A case-control analysis of predicted truncating variants in the 32 genes was performed. Using a minimum alternate allele frequency of 30%, we identified a higher frequency of mutations in non-HGS cases than controls in ERCC6 (p=0.034) and IL31RA (p=0.034). ERCC6 is involved in DNA repair and IL31RA is a cytokine receptor. Sanger sequencing validation of variants to confirm these results is ongoing. Several other genes showed suggestive higher frequencies of mutations in cases than controls. A larger case control analysis will be performed to confirm those findings. Identifying novel susceptibility genes for non-HGS may have clinical impact by reducing disease-associated mortality through improving risk prediction, identifying prevention strategies, and developing new targeted treatments. Citation Format: Marina Pavanello, Ed Dicks, Honglin Song, Amir Ariff, Adelyn Bolithon, Maria P. Intermaggio, Mark Pinese, Kirsten Moysich, Kunle O. Odunsi, Ellen Goode, David D. Bowtell, Peter Fasching, Jennifer A. Doherty, Francesmary Modugno, Susanne K. Kjær, Penelope M. Webb, Anna Wu, Anna deFazio, Ovarian Cancer Association Consortium, Paul James, Deepak Subramanian, Ian Campbell, Simon A. Gayther, Paul D.P. Pharoah, Susan J. Ramus. Germline mutations in new susceptibility genes for non-high-grade serous ovarian cancer [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr B37.

1041P - Clinical features and frequency of mismatch repair protein deficiency in ovarian clear cell and endometrioid carcinoma patients

BackgroundThe rates of mismatch repair (MMR) protein deficiency and microsatellite instability (MSI) in ovarian clear cell (CC) and endometrioid (EM) cancer patients were investigated. The clinical features of CC and EM were also analyzed. MethodsPatients postoperatively diagnosed as CC or EM carcinoma from January 2006 to December 2015 were eligible. Diagnosis of all cases was confirmed by the Central Pathological Review Board. MMR protein was analyzed by IHC using a monoclonal antibody and MSI was examined by a multiplex PCR assay for five microsatellite markers, BAT25, BAT26, NR-21, NR-24, and MONO-27. MLH1 IHC-negative cases were examined for DNA hypermethylation of the MLH1 promoter. ResultsWe enrolled 339 cases consisting of 219CC, 116 EM and 4 mixed type (MT) cases. One case could not be evaluated by IHC. MMR protein deficiency was confirmed in five CC (2.3%), 16 EM (13.9%) and 1MT case (25%). Deficiency was observed in 4 cases for MLH1 and PMS2, in 13 cases for MSH2 and MSH6, in 1 case for MSH2 and PMS2, in 2 cases for MSH6, and in 1 case for PMS2. DNA hypermethylation of the MLH1 promoter was detected in one of the four MLH1 and PMS2 deficiency cases. Three of the 339 cases could not be evaluated by MSI. A high rate of MSI was confirmed in 13 cases (3.9%) and MMR deficiency was detected by IHC in these cases. However, MSI was not detected in the other nine cases where MMR deficiency was detected by IHC. The median age of all 339 cases was 54 (CC 54, EM 51) and that of CC and EM cases with MMR deficiency was 39 and 48 years, respectively. ConclusionsThe rate of MMR deficiency in CC and EM was not high, whereas CC in young women was more frequent. IHC is a more successful screening method of MMR deficiency in ovarian CC and EM compared with MSI detection. The rate of MLH1 promoter hypermethylation (epigenetic MMR deficiency) in ovarian CC and EM was less than that of endometrial cancer. Legal entity responsible for the studyThe author. FundingNational Hospital Organization of Japan. DisclosureThe author has declared no conflicts of interest.

The effect of dinitrosyl iron complexes with glutathione and S-nitrosoglutathione on the development of experimental endometriosis in rats: A comparative studies

It has been established that intraperitoneal bolus administration of S-nitrosoglutathione (GS-NO) (12.5μmoles/kg; 10 injections in 10 days), beginning with day 4 after transplantation of two 2-mm autologous fragments of endometrial tissue onto the inner surface of the abdominal wall of rats with surgically induced (experimenta) endometriosis failed to prevent further growth of endometrioid (EMT) and additive tumors, while treatment of animals with dinitrosyl iron complexes (DNIC) with glutathione (12.5μmoles/kg, 10 injections in 10 days) suppressed tumor growth virtually completely. The histological analysis of EMT samples of GS-NO-treated rats revealed pathological changes characteristic of control (non-treated with GS-NO or DNIC) rats with experimental endometriosis. EPR studies established the presence of the active form of ribonucleotide reductase, a specific marker for rapidly proliferating tumors, in EMT samples of both control and GS-NO-treated animals. Noteworthy, in small-size EMT and adjacent tissues of DNIC-treated rats the active form of ribonucleotide reductase and pathological changes were not found.

Ovarian cancers arising from endometriosis: A microenvironmental biomarker study including ER, HNF1ß, p53, PTEN, BAF250a, and COX-2

BackgroundThe microenvironmental biomarkers of different subtypes of ovarian cancers arising from endometriosis have not been studied in Taiwan. Their expression can help in understanding the carcinogenic mechanism. MethodsOur study used immunohistochemistry to compare the expression of estrogen receptor (ER), hepatocyte nuclear factor-1 beta (HNF1ß), p53, phosphatase and tensin homolog (PTEN), BAF250a, and cyclooxygenase-2 (COX-2) among 79 cases of endometriosis-associated ovarian cancers, including 40 (50%) clear cell carcinomas (CCCs), 33 (41%) endometrioid (EM) adenocarcinomas, four (5%) serous carcinomas, one adenosquamous carcinoma, and one adenosarcoma. ResultsPositive stainings for ER, HNF1ß, p53, and COX-2 were identified in 34 (43%), 30 (38%), 10 (13%), and 44 (56%) cases. Loss of PTEN and BAF250a were noted in 29 (37%) and 37 (47%) cases. The expression of ER was reversely correlated with that of HNF1ß (rho = −0.417, p < 0.001) and correlated with p53 (rho = 0.284, p = 0.011). ER positivity was commonly identified in EM adenocarcinomas (91%), and rarely in CCCs (8%) and serous carcinoma (0%; p < 0.001). By contrast, HNF1ß expression was frequently noted in CCCs (65%) and serous carcinomas (50%), but less in EM adenocarcinoma (6%; p < 0.001). All staining results were similar between atypical endometriosis glandular epithelium and contiguous malignant parts. Only nine cases showed 10 minor differences (10/474, 2%) in ER, HNF1ß, and BAF250a. For the staining patterns of p53, COX-2, and PTEN, there was no difference between the invasive and precursor parts. ConclusionOur results supported the suggestion that estrogen-dependent ovarian cancer arising from endometriosis is substantially more associated with EM adenocarcinoma than CCCs. The positive HNF1ß staining was a frequent finding in CCCs, but not in EM adenocarcinoma. The similar staining patterns of atypical endometriosis glandular cells with the invasive parts confirmed their precursor status.

Genes with Bimodal Expression Are Robust Diagnostic Targets that Define Distinct Subtypes of Epithelial Ovarian Cancer with Different Overall Survival

In some cancer types, certain genes behave as molecular switches, with on and off expression states. These genes tend to define tumor subtypes associated with different treatments and different patient survival. We hypothesized that clinically relevant molecular switch genes exist in epithelial ovarian cancer. To test this hypothesis, we applied a bimodal discovery algorithm to a publicly available ovarian cancer expression microarray data set, GSE9891 [285 tumors: 246 malignant serous (MS), 20 endometrioid (EM), and 18 low malignant potential (LMP) ovarian carcinomas]. Genes with robust bimodal expression patterns were identified across all ovarian tumor types and also within selected subtypes: 73 bimodal genes demonstrated differential expression between LMP versus MS and EM; 22 bimodal genes distinguished MS from EM; and 14 genes had significant association with survival among MS tumors. When these genes were combined into a single survival score, the median survival for patients with a favorable versus unfavorable score was 65 versus 29 months (P < 0.0001, hazard ratio = 0.4221). Two independent data sets [high-grade, advanced-stage serous (n = 53) and advanced-stage (n = 119) ovarian tumors] validated the survival score performance. We conclude that genes with bimodal expression patterns not only define clinically relevant molecular subtypes of ovarian carcinoma but also provide ideal targets for translation into the clinical laboratory.

Comparison of Survival Outcomes Between Patients With Malignant Mixed Mullerian Tumors and High-Grade Endometrioid, Clear Cell, and Papillary Serous Endometrial Cancers

Malignant mixed mullerian tumors (MMMTs) are an aggressive subtype of endometrial cancer (EC). Previous studies compare survival between high-grade endometrioid (EM), clear cell (CC), and papillary serous (PS) ECs; yet few studies compare MMMTs to these aggressive subtypes. The goal of this study was to compare recurrence-free survival (RFS), disease-specific survival (DSS), and overall survival (OS) among EC subtypes. We conducted a retrospective cohort study of EC cases treated at Magee-Women's Hospital between 1996 and 2008. Kaplan-Meier estimates of RFS, DSS, and OS as well as and log-rank tests were used to compare survival distributions between histologic subtypes. Cox regression was used to estimate hazard ratios for histologic subtypes, adjusted for other significant prognostic factors. Interactions between histologic subtype and prognostic factors were examined to assess effect modification. This cohort included 81 MMMT (15%), 254 high-grade EM (46%), 73 CC (13%), and 147 PS (26%) cases. Compared to high-grade EM (6%) and CC (7%) cases, relatively more MMMT (12%) and PS (12%) cases were nonwhite. Stage differed significantly among the subtypes, with 36%, 34%, 37%, and 51% of MMMT, high-grade EM, CC, and PS cases, respectively, diagnosed at advanced late stage (P<0.001). Kaplan-Meier curves and log-rank tests showed similar RFS, DSS, and OS between MMMT, high-grade EM, CC, and PS cases stratified by stage. In adjusted Cox regression models, RFS and DSS were not significantly different between MMMT and other subtypes. High-grade EM cases had a significantly better OS compared to MMMT cases (HR, 0.63; 95% confidence interval [CI], 0.41-0.98). This is the first retrospective study to suggest that certain survival outcomes are similar among MMMT, high-grade EM, CC, and PS subtypes. Other large-scale studies are needed to confirm these findings.

ABCF2 expression in endometrial cancer and breast cancer

5035 Background: ABCF2 is a new member of the ATP-binding cassette transporter superfamily gene. We previously reported that ABCF2 protein is new biomarker in clear cell adenocarcinoma (CC) of the ovary and its expression may predict the response to chemotherapy and survival of CC patients (Proc ASCO 2005, Clin Cancer Res 2005). Both breast cancer (BC) and endometorial cancer (EC) are estrogen-dependent tumors, however, their biological behavior differ. In this study, we examined ABCF2 expression in EMCA and BC and evaluated the relationship between ABCF2 expression and clinical factor. Methods: Formalin-fixed surgical samples from 100 EMCA and 191 BC patients were included in this study. ABCF2 expression was investigated by immunohistochemistry. Positive expression of ABCF2 was &gt; 10% based on the cytoplasmic staining. Results: Histologic types and stage were as followed: EMCA: (Endometrioid (EM): 92; Adenosquamous (AS): 8), (I: 63; II: 5; III: 30; IV: 2). BC: (Papillo tu (PP): 60; Solid tub (SL): 38; Scirrhous (SC): 77; Other (OT): 15). Breast cancer was sub-classified into 3 types according to the criteria of the Japanese Breast Cancer Society. The relationship between ABCF2 expression and histologic type was shown in table. In EMCA and BC, there were no significant relationship between ABCF2 expression and clinical factor like stage, histologic type, grade and estrogen receptor (ER). In EMCA, ABCF2 expression was not related with disease free survival (DFS). However, in BC, ABCF2-positive tumors had longer DFS than ABCF2-negative tumors (p = 0.03). The ABCF2 expression were correlated with further biological variables such as tumor stage, lympho node metastasis, nuclear grade and ER status for DFS by univariate and multivariate Cox regression analysis. Multivariate analysis revealed that ABCF2 was an independent prognostic factor (HR 0.46; p = 0.018). Conclusion: The role of ABCF2 protein may differ between EMCA and BC. [Table: see text] No significant financial relationships to disclose.

Histopathologic subtyping of cervical adenocarcinoma reveals increasing incidence rates of endometrioid tumors in all age groups

The effect of histopathologic review and subclassification on incidence rates for nonsquamous cell carcinoma (non-SCC) of the uterine cervix in the Norwegian population was evaluated. All non-SCC from three 5-year periods (1966-70, 1976-80, and 1986-90) were reviewed, classified, and graded. Incidence rates were 1.2, 1.2, and 1.7 per 100,000 for adenocarcinoma and 0.1, 0.3, and 0.5 per 100,000 for other carcinomas in the three periods. Adenocarcinomas increased in all age groups, most markedly in women younger than 35 years. Incidence rates for both major subgroups of endocervical (EC) and endometrioid (EM) carcinomas increased for women younger than 55 years. After 1976-80, the incidence rate for EC, but not for EM, decreased in women older than 55 years. Endometrioid carcinoma became the dominant histologic subtype in 1986-90. Shifts toward lower clinical stages and younger age were found for EC, EM, and carcinoma not otherwise specified (NOS). Patients with NOS, clear cell, serous, or glassy cell/undifferentiated carcinoma were older, and their disease was diagnosed at higher stages. Distribution of International Federation of Gynecology and Obstetrics (FIGO) stages was: Stage I: 62%; Stage II: 21%; Stage III: 12%; and Stage IV: 5%. Distribution of histologic subgroups was: EC:, 24%; EM: 21%; NOS: 16%; clear cell: 7%; adenosquamous: 7%; small cell: 6%; serous: 4%; undifferentiated: 3%; and villoglandular carcinoma: 2%. Other subgroups were seen only sporadically. Incidence rates of non-SCC of the uterine cervix are increasing in Norway. Improvements in diagnostic procedures may explain shifts toward lower stage and age of patients but not the observed differences between histologic subgroups.

The Outcome of Stage I–II Clinically and Surgically Staged Papillary Serous and Clear Cell Endometrial Cancers When Compared with Endometrioid Carcinoma

Purpose. The aim of this study was to compare survival and recurrence in clinical and surgical stage I–II papillary serous (PS), clear cell (CC), and endometrioid (EM) cancers of the endometrium and examine the prognostic utility of myometrial invasion.Methods. Clinical, surgicopathologic, and survival data were retrospectively collected on 574 clinical stage I–II endometrial cancer patients, including 53 PS and 18 CC (based on postoperative histology), undergoing hysterectomy at Duke University Medical Center between 1967 and 1990. All staging material was available and reexamined prior to this analysis, and FIGO surgical staging was retrospectively assigned. Prognostic variables examined included age, stage, grade, myometrial invasion, lymph–vascular space invasion (LVSI), and histology. PS and CC histologic subtypes were compared as both common category and discrete categories versus EM, EM grade 1 (EM1), EM grade 2 (EM2), and EM grade 3 (EM3). Statistical analyses were performed using χ2, Fisher's exact, and Wilcoxon rank sum tests, Cox regression analysis, and Kaplan–Meier survival analysis.Results. PS tumors accounted for 9%, CC for 3%, and EM for 88% of cases. Recurrences were more frequent among PS (38%) and CC (22%) compared with EM (9%) (P < 0.001 and 0.08, respectively), and PS recurred more frequently than EM3 alone (20%) (P = 0.06). Among PS, CC, and EM3 patients with recurrences there were no statistical differences in the proportion that received preoperative or postoperative radiotherapy or chemotherapy. Prognostic factors for shorter survival included age >=60, surgical stage III+IV, presence of LVSI, histology (PS, CC, or EM3), and >=50% myometrial invasion. The estimated 5-year survival of PS+CC patients with <2 mm myometrial invasion is 0.56 compared to 0.93 for EM patients (P < 0.001). PS + CC tumors confined to the endometrium had a 5-year survival of 0.60 compared to 0.98 and 1.00 for EM and EM3, respectively. The 5-year survival for surgically staged IA patients (0.57) was not different from stages IB and IC combined (0.53) (P = 0.72). The 5-year survival for surgical stage I + II PS + CC patients (0.56) was comparable to that for clinical stage I + II PS + CC patients (0.46) and remained significantly smaller than that for EM patients (0.86) (P < 0.001).Conclusion. Recurrences are more frequent among PS and CC tumors compared with EM and among PS compared with EM3. When controlled for surgical stage I–II tumors, 5-year survival for PS + CC patients remains comparable to that of clinical stage I–II patients and below that of EM. Prognostic factors for survival in PS and CC patients include age, stage, and LVSI. PS, CC, and EM3 subtypes together are predictors of poor survival. Thorough extended surgical staging is indicated in PS and CC tumors, and prospective trials of aggressive adjuvant therapies for surgical stage I–II tumors are needed to improve outcome in PS and CC patients.

Epidemiologic and Surgicopathologic Findings of Papillary Serous and Clear Cell Endometrial Cancers When Compared to Endometrioid Carcinoma

Purpose. The aim of this study was to identify similarities and differences in epidemiologic and surgicopathologic staging results for papillary serous (PS) and clear cell (CC) endometrial cancers compared with endometrioid (EM) carcinoma of the endometrium.Methods. Clinical and surgicopathologic data were retrospectively collected on 574 clinical stage I–II endometrial cancer patients, including 53 PS and 18 CC (based on postoperative histology), undergoing hysterectomy at Duke University Medical Center between 1967 and 1990. All staging material was available and reexamined prior to this analysis, and FIGO surgical staging was retrospectively assigned. PS and CC histologic subtypes were compared both as a common category and as discrete categories versus EM, EM grade 1 (EM1), EM grade 2 (EM2), and EM grade 3 (EM3). Fisher's exact test was used to compare proportions with unordered categories (2 × 2 tables), while the χ2 test for trend was used to compare proportions in 3 × 2 tables with ordered categories. Differences in medians were compared with the Wilcoxon rank-sum test.Results. PS tumors accounted for 8%, CC for 2%, and EM for 90% of cases. Overall, 14% of tumors were changed to a different postoperative histology including 64% of PS, 50% of CC, and 8% of EM. Postoperative histology changes were 4% for EM1 and 21% for EM3. PS, CC, and EM3 had more surgical sampling performed than for other EM. Rates for lymph node dissections were similar for EM3 (81%), PS (72%), and CC (67%) tumors, although metastases were more frequent for PS and CC compared with EM3. When PS tumors were confined to the endometrium, paraaortic metastases occurred in 13%. LVSI increased with EM grade and was highest for PS and CC. Upstaging to surgical stage III–IV occurred in 47% of PS, 39% of CC, and 12% of EM. The majority of PS and CC tumors were confined to the inner one-third of the myometrium, compared with EM tumors, where grade correlated with depth of myometrial invasion. Extrauterine metastases occurred in 55% of PS and 45% of CC tumors confined to the inner one-half, compared with 17% of EM3.Conclusion. Frequent changes from preoperative to postoperative histology and grade may contribute to misassignment of preoperative and intraoperative risk as determined by depth of myometrial invasion for PS and CC patients. The higher frequency of extrauterine metastases in PS and CC tumors compared with EM3, despite similar surgical sampling rates, supports a more virulent behavior. The poor correlation between depth of myometrial invasion and risk for extrauterine metastases helps to explain poorer survival in PS and CC patients, in addition to more frequent upstaging. These results support routine extended surgical staging for women with preoperative or intraoperative diagnosis of PS and CC tumors. Intraoperative assessment of tumor grade and histology may be indicated and warrants further investigation.