High-grade Serous Ovarian Cancer Cases Research Articles

Abstract 2253: Plasma metabolomic profiles associated with early and late-stage high-grade serous ovarian cancer

Abstract Background: Ovarian cancer has poor survival due to more than 60% of patients being diagnosed at advanced stage. Therefore, discovery of novel, non-invasive early detection biomarkers has high potential to improve survival. Here, we identified plasma metabolomic profiles associated with early-stage and late-stage high-grade serous ovarian cancer (HGSOC), the most common histotype. Method: We examined 197 lipid and lipid-related metabolites measured using a validated, liquid chromatography tandem mass spectrometry method (Broad Institute, Cambridge, MA) in plasma collected prior to surgery from 40 early-stage and 40 late-stage HGSOC patients and 40 population-based controls matched on age, year, and menopausal status at blood draw. We used multivariable logistic regression, adjusted for matching factors, tubal ligation, oral contraceptive use, and parity, to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) of ovarian cancer risk per 1 standard deviation increase in probit-transformed metabolite levels. We used Metabolite Set Enrichment Analysis (MSEA) to identify metabolite groups. We accounted for testing multiple correlated hypotheses using the number of effective tests (NEF) or false discovery rate (FDR). Results: Compared to controls, there were 34 metabolites associated with early-stage HGSOC and 88 metabolites associate with late-stage HGSOC (unadjusted p-value<0.05). All metabolites associated with risk of early-stage HGSOC and majority (n=80, 90%) of the metabolites associated with risk of late-stage HGSOC were inversely associated with ORs ranging from 0.28 to 0.48 for early-stage and 0.08 to 0.59 for late-stage HGSOC. Interestingly, the direction of association across all these metabolites were similar in both early-stage and late-stage HGSOC, with stronger effect estimates for late-stage HGSOC. After multiple testing correction, there were 9 statistically significant metabolites associated with risk of late-stage HGSOC (NEF p-value<0.05) whereas no individual metabolites remained associated with risk of early-stage HGSOC. MSEA revealed similar patterns of association compared to controls across the 11 lipid groups assessed in early and late-stage HGSOC cases. Metabolite groups of phosphatidylethanolamine plasmalogens and triglycerides were inversely associated with early-stage HGSOC compared to controls (FDR p-value<0.05). Metabolite groups of phosphatidylethanolamine plasmalogens and phosphatidylcholines were inversely, and diglycerides were positively associated with late-stage HGSOC compared to controls (FDR p-value<0.05). Conclusion: Our results revealed early-stage and late-stage HGSOC having similar plasma metabolomic profiles overall although there were more metabolites that were significantly associated with late-stage HGSOC than early-stage HGSOC compared to population-based controls. Citation Format: Naoko Sasamoto, Oana A. Zeleznik, Allison F. Vitonis, Daniel W. Cramer, Julian Avila-Pacheco, Clary B. Clish, Shelley S. Tworoger, Kathryn L. Terry. Plasma metabolomic profiles associated with early and late-stage high-grade serous ovarian cancer [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 2253.

Data independent acquisition mass spectrometry in relation to potential diagnostic and prognostic biomarkers for high-grade serous ovarian cancer.

e17564 Background: Ovarian cancer (OC) is one of the most common causes of cancer-related death among women worldwide. High-grade serous ovarian cancer (HGSOC) represents the major OC histological type, and challenges associated with its early detection and prediction of clinical outcomes significantly contribute to the high prevalence and poor prognosis of OC. Lack of reliable biomarkers further exacerbates the low survival rate of patients with HGSOC. Methods: In this study, we performed liquid chromatography data independent acquisition tandem-mass spectrometry (LC-DIA-MS/MS) experiments on depleted serum samples [26 HGSOC cases, 24 healthy controls (HCs)] to identify potential diagnostic and prognostic biomarkers for HGSOC. Results: A total of 1,148 proteins were identified in all samples combined, representing one of the largest quantifications in the serum proteome of OC to date. Among them, 122 proteins showed differential expressions between the serum proteome of HGSOC patients and HCs, including 109 up- and 14 down-regulated proteins in HGSOC. These potential diagnostic biomarkers were involved in the pathways related to immune response, TGF- β and IGF signaling, and lipid metabolism. Moreover, we performed Kaplan-Meier survival analysis on the HGSOC patients with and without recurrence, and identified several potential prognostic biomarkers highly associated with progression free survival (PFS). Using independent cohort samples, we validated the expression levels of HGSOC serum biomarker candidates using targeted proteomics approaches (MRM and PRM). In vitro functional assays revealed that some of these biomarkers may play an essential role in cancer cell migration and proliferation in HGSOC. Conclusions: In summary, our LC-DIA-MS/MS analysis of the HGSOC serum proteome successfully identified novel diagnostic and prognostic biomarkers for HGSOC, some of which were experimentally shown to have functional relevance to the pathophysiology of OC.

Abstract 2881: Snail-mediated regulation of MMP1 expression in the context of ovarian cancer invasiveness

Abstract Ovarian cancer ranks fifth among the causes of cancer death in US women. Despite initial positive response to cytoreductive surgery and chemotherapy treatments with platinum-based therapies, over 80% of patients with high-grade serous ovarian cancer (HGSOC), the most common type of ovarian cancer, exhibit relapse. Most recurrent cases of HGSOC are resistant to chemotherapy, and cells are highly invasive. Therefore, further studies are required to understand the mechanisms of invasiveness and chemoresistance in relapse patients. In HGSOC, invasiveness can result when epithelial cancer cells undergo epithelial-mesenchymal transition (EMT). The transcription factor SNAI1 (Snail) initiates the EMT process and increased Snail expression can result in enhancement of metastatic potential, acquisition of stem cell-like characteristics, and resistance to chemotherapeutic drugs. However, the mechanism of activation of invasiveness in ovarian cancer by Snail has not been defined. In OVCAR8, a HGSOC cell line, comparison of shSnail knockdown to control through RNA-sequencing revealed that Snail expression is directly correlated to matrix metalloprotease 1 (MMP1) expression. MMP1 is an extracellular matrix remodeler known to digest interstitial collagens. High MMP1 expression has been linked to increased cancer invasion, metastasis, angiogenesis, and apoptosis. Furthermore, in breast cancer, MMP1 has been reported to be a downstream target of Slug, another major EMT transcription factor. Some evidence for Snail activation of MMPs in liver cancer has been presented, but a direct relationship has not been established. Therefore, we hypothesize that overexpression of Snail in ovarian cancer cells results in MMP1 upregulation, leading to increased invasion. RT-qPCR was performed to analyze relative mRNA expression levels of Snail and MMP1 in eight cell lines. We found that Snail and MMP1 levels were higher in the more mesenchymal-like cell lines, some of which are known to be more invasive. Additionally, Snail overexpression led to a significant corresponding increase in MMP1 mRNA expression and resistance to cisplatin. Chromatin immunoprecipitation (ChIP) experiments demonstrate Snail binding to the MMP1 promoter. Thus, our preliminary findings have shown strong evidence of a Snail-mediated regulation of MMP1 expression in the context of HGSOC invasiveness. Citation Format: Tise Suzuki, Casey Curow, Hanmin Wang, Asis Martinez, Nozomi Hojo, Juli Unternaehrer. Snail-mediated regulation of MMP1 expression in the context of ovarian cancer invasiveness [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 2881.

EVI1 overexpression promotes ovarian cancer progression by regulating estrogen signaling

High-grade serous ovarian cancer (HGSOC) is characterized by TP53 mutation and somatic copy number alterations (SCNAs). Here we show that the oncogenic transcription factor EVI1 (ecotropic viral integration site-1) is amplified and overexpressed up to 30% of 1640 HGSOC cases in The Cancer Genome Atlas (TCGA). Functionally, EVI1 promotes proliferation/invasion in vitro and tumor growth of xenograft model in vivo. Importantly, we discover that EVI1 regulates estrogen signaling by directly activating ESR1 (estrogen receptor 1) transcription determined by the ChIP and luciferase assay. Interestingly, EVI1 and ESR1 share common regulatory targets as indicated by the analysis of ChIP-Seq data. EVI1 and ESR1 collaborate in the regulation of some estrogen receptor-regulated genes. Furthermore, EVI1 drives tumor aggressiveness partially by regulating estrogen signaling. Estrogen enhances the proliferation, invasion and xenograft growth of ovarian cancer cells. Importantly, estrogen can rescue the inhibition of proliferation, invasion and xenograft growth induced by silencing EVI1. These findings suggest that EVI1 functions as a novel regulator of the estrogen signaling network in ovarian cancer.

Low Expression of Circular RNA hsa_circ_0078607 Predicts Poor Prognosis in High-Grade Serous Ovarian Cancer.

ObjectiveRecent studies have shown that circRNAs participate in ovarian cancer progression and act as potential biomarkers for ovarian cancer diagnosis and prognosis. In the present study, we aimed to investigate the expression pattern and prognostic significance of circ_0078607 in high-grade serous ovarian cancer (HGSOC).MethodsThe expression of circ_0078607 was detected by quantitative real-time polymerase chain reaction (qRT-PCR) in 49 cases of HGSOC. Clinical data of patients with HGSOC were retrospectively collected, and those patients were divided according to their expression of circ_0078607. Correlation between circ_0078607 and clinical features as well as the prognosis in patients with HGSOC was analyzed. t-test and chi-square test were used to compare continuous and categorical variables. The Cox hazard regression model was used to assess prognostic factors. Both progression-free survival (PFS) and overall survival (OS) curves were generated by Kaplan–Meier method.ResultsThe expression of circ_0078607 was significantly downregulated in ovarian cancer tissues compared with adjacent non-cancerous tissues. Besides, patients with low circ_0078607 expression exhibited parameters associated with poor prognosis, including advanced FIGO stage and higher serum CA125 level. Kaplan–Meier survival curve analysis showed that patients with low circ_0078607 expression had shorter PFS and OS. Cox regression analysis showed that low expression of circ_0078607 was a predictor for poor PFS and OS in HGSOC patients.ConclusionLow expression of circ_0078607 might be an adverse prognostic indicator for HGSOC.

Discovery of a biomarker candidate for surgical stratification in high-grade serous ovarian cancer

BackgroundMaximal effort cytoreductive surgery is associated with improved outcomes in advanced high-grade serous ovarian cancer (HGSOC). However, despite complete gross resection (CGR), there is a percentage of patients who will relapse and die early. The aim of this study is to identify potential candidate biomarkers to help personalise surgical radicality.Methods136 advanced HGSOC cases who underwent CGR were identified from three public transcriptomic datasets. Candidate prognostic biomarkers were discovered in this cohort by Cox regression analysis, and further validated by targeted RNA-sequencing in HGSOC cases from Imperial College Healthcare NHS Trust (n = 59), and a public dataset. Gene set enrichment analysis was performed to understand the biological significance of the candidate biomarker.ResultsWe identified ALG5 as a prognostic biomarker for early tumour progression in advanced HGSOC despite CGR (HR = 2.42, 95% CI (1.57–3.75), p < 0.0001). The prognostic value of this new candidate biomarker was additionally confirmed in two independent datasets (HR = 1.60, 95% CI (1.03–2.49), p = 0.0368; HR = 3.08, 95% CI (1.07–8.81), p = 0.0365). Mechanistically, the oxidative phosphorylation was demonstrated as a potential biological pathway of ALG5-high expression in patients with early relapse (p < 0.001).ConclusionALG5 has been identified as an independent prognostic biomarker for poor prognosis in advanced HGSOC patients despite CGR. This sets a promising platform for biomarker combinations and further validations towards future personalised surgical care.

A comprehensive analysis of the expression, epigenetic and genetic changes of HNF1B and ECI2 in 122 cases of high-grade serous ovarian carcinoma.

High-grade serous ovarian cancer (HGSC) is the most common subtype of ovarian cancer, with a poor prognosis; however, most studies concerning ovarian carcinoma have focused mainly on clear cell carcinoma. The involvement of hepatocyte nuclear factor 1β (HNF1B) in the carcinogenesis of HGSC has not yet been fully elucidated. To the best of our knowledge, the present study is the first to analyse the expression of the possible downstream target of HNF1B, enoyl-CoA (Δ) isomerase 2 (ECI2), in HGSC. The present study performed a comprehensive analysis of HNF1B mRNA and protein expression, and epigenetic and genetic changes, as well as an analysis of ECI2 mRNA and protein expression in 122 cases of HGSC. HNF1B protein expression was detected in 28/122 cases, and was positively associated with lymphovascular invasion (P=0.025). Protein expression of ECI2 was detected in 115/122 cases, but no associations with clinicopathological variables were revealed. Therefore, ECI2 does not seem to function as a suitable prognostic marker for HGSC. In the sample set, a positive correlation between HNF1B and ECI2 protein expression was detected (P=0.005). HNF1B mRNA was also positively correlated with HNF1B protein expression (P=0.001). HNF1B promoter methylation was detected in 26/67 (38.8%) of cases. A novel pathogenic somatic HNF1B mutation was detected in 1/61 (1.6%) of the analysed HGSC cases. No other correlations between the examined SNPs (rs4430796, rs757210 and rs7405776), HNF1B promoter methylation, HNF1B/ECI2 expression or clinicopathological characteristics were found.

CXCL13 shapes immunoactive tumor microenvironment and enhances the efficacy of PD-1 checkpoint blockade in high-grade serous ovarian cancer

BackgroundMost patients with high-grade serous ovarian cancer (HGSC) lack an effective response to immune checkpoint blockade, highlighting the need for more knowledge about what is required for successful treatment. As...

Clinical and pathological significance of programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) expression in high grade serous ovarian cancer

We investigated programmed cell death 1 (PD-1) / programmed cell death ligand 1 (PD-L1) expression in high grade serous ovarian cancer (HGSOC) and its relationship to tumor infiltrating lymphocytes (TIL) and prognosis. Formalin fixed paraffin embedded (FFPE) samples of 94 HGSOC cases were included in the study. Immunohistochemical analysis (CD3, CD4, CD8, PD-1 and PD-L1) was performed. Samples were analyzed for expression of immune proteins in the peritumoral stromal and intratumoral areas, scored, and expression was correlated with overall survival, stage, and age. PD-L1 staining ratio with a score greater than 0 was found to have lower survival. There were two positive staining patterns, patchy/diffuse and patchy/focal patterns, in 24 (25.5%) cases. Considering the threshold value ≥5%, we demonstrated that the PD-L1 positive cancer cell membrane immunoreactivity rate and patchy/diffuse PD-L1 expression were 9.6% (n = 9). There was statistically significant relationship between high PD-1 scores and PD-L1 cases of ≥ 5%. A statistically significant difference was found between PD-L1 staining and survival in patients with a threshold ≥ 5%. However an appropriate rate for treatment was determined in 9.6% cases. There was a statistically significant correlation between PD-1 positive TIL score and intratumoral CD3, peritumoral stromal CD3, intratumoral CD4 and intratumoral CD8 positive cells. Survival was lower in cases with higher PD-L1 positive stromal TIL score.

Reduced RBX1 expression induces chromosome instability and promotes cellular transformation in high-grade serous ovarian cancer precursor cells.

Despite high-grade serous ovarian cancer (HGSOC) being the most common and lethal gynecological cancer in women, the early etiological events driving disease development remain largely unknown. Emerging evidence now suggests that chromosome instability (CIN; ongoing changes in chromosome numbers) may play a central role in the development and progression of HGSOC. Importantly, genomic amplification of the Cyclin E1 gene (CCNE1) contributes to HGSOC pathogenesis in ~20% of patients, while Cyclin E1 overexpression induces CIN in model systems. Cyclin E1 levels are normally regulated by the SCF (SKP1-CUL1-FBOX) complex, an E3 ubiquitin ligase that includes RBX1 as a core component. Interestingly, RBX1 is heterozygously lost in ~80% of HGSOC cases and reduced expression corresponds with worse outcomes, suggesting it may be a pathogenic event. Using both short (siRNA) and long (CRISPR/Cas9) term approaches, we show that reduced RBX1 expression corresponds with significant increases in CIN phenotypes in fallopian tube secretory epithelial cells, a cellular precursor of HGSOC. Moreover, reduced RBX1 expression corresponds with increased Cyclin E1 levels and anchorage-independent growth. Collectively, these data identify RBX1 as a novel CIN gene with pathogenic implications for HGSOC.

Targeted nanopore sequencing for the identification of ABCB1 promoter translocations in cancer

BackgroundResistance to chemotherapy is the most common cause of treatment failure in acute myeloid leukemia (AML) and the drug efflux pump ABCB1 is a critical mediator. Recent studies have identified promoter translocations as common drivers of high ABCB1 expression in recurrent, chemotherapy-treated high-grade serous ovarian cancer (HGSC) and breast cancer. These fusions place ABCB1 under the control of a strong promoter while leaving its open reading frame intact. The mechanisms controlling high ABCB1 expression in AML are largely unknown. We therefore established an experimental system and analysis pipeline to determine whether promoter translocations account for high ABCB1 expression in cases of relapsed human AML.MethodsThe human AML cell line THP-1 was used to create a model of chemotherapy resistance in which ABCB1 expression was driven by a promoter fusion. The THP-1 model was used to establish a targeted nanopore long-read sequencing approach that was then applied to cases of ABCB1high HGSC and AML. H3K27Ac ChIP sequencing was used to assess the activity of native promoters in cases of ABCB1high AML.ResultsProlonged in vitro daunorubicin exposure induced activating ABCB1 promoter translocations in human THP-1 AML cells, similar to those recently described in recurrent high-grade serous ovarian and breast cancers. Targeted nanopore sequencing proved an efficient method for identifying ABCB1 structural variants in THP-1 AML cells and HGSC; the promoter translocations identified in HGSC were both previously described and novel. In contrast, activating ABCB1 promoter translocations were not identified in ABCB1high AML; instead H3K27Ac ChIP sequencing demonstrated active native promoters in all cases studied.ConclusionsDespite frequent high level expression of ABCB1 in relapsed primary AML we found no evidence of ABCB1 translocations and instead confirmed high-level activity of native ABCB1 promoters, consistent with endogenous regulation.

Protein anabolism is key to long-term survival in high-grade serous ovarian cancer

This study aimed to identify the biological processes associated with long-term survival in high-grade serous ovarian cancer (HGSOC). HGSOC cases obtained from The Cancer Genome Atlas Ovarian Cancer (TCGA-OV) database were divided into long-term survivors (LTS) and normal-term survivors (NTS) based on survival cutoffs defined by the HGSOC cohort in the SEER database. Differentially expressed genes (DEGs) were screened using the generalized linear modeling (GLM) method. Gene Ontology (GO) functional and KEGG pathway enrichment analyses were performed using DAVID Bioinformatics Resources. DEG-related protein-protein interactions (PPI) were extracted from the STRING database and hub genes were identified using CytoHubba in the Cytoscape program. In total, 157 DEGs, including 155 upregulated and 2 downregulated genes, were identified. Upregulated genes were statistically enriched in 80 GO terms and 11 KEGG pathways related to energy and substrate metabolism, such as protein absorption, digestion, and metabolism as well as signaling pathways, including chromatin silencing, regulation of ERK1 and ERK2 cascade, and regulation of MAPKKK. ALB and POMC were the common hub genes. These findings reveal that protein anabolism is crucial to long-term survival, regulated by activation of the MAPK/ERK signaling pathway and chromatin silencing. Comprehensive understanding of the molecular mechanisms via further exploration may contribute toward an effective treatment for ovarian cancer.

Spectrum of TP53 Mutations in BRCA1/2 Associated High-Grade Serous Ovarian Cancer.

Objective: Mutations in TP53 lead to loss of function (LOF) or gain of function (GOF) of the corresponding protein p53 and produce a different effect on the tumor. Our goal was to determine the spectrum of somatic TP53 variants in BRCA1/2 associated high-grade serous ovarian cancer (HGSOC).Methods: The population under study comprised of HGSOCs with pathogenic variants in BRCA1 (n = 78) or BRCA2 (n = 21). Only chemo-naive and platinum-sensitive patients were included in this study. The case group of the IARC database (n = 1249) with HGSOC not stratified by BRCA status was used as a reference. A custom NGS panel was used for sequencing TP53 and mutational hot-spots of other genes, and p53 expression was evaluated by immunohistochemistry for 68 cases of HGSOCs.Results: Somatic TP53 variants (95) or inhibition of wild-type p53 expression (3) were observed in 98 cases. The sample with normal p53 had CDKNA1 variants. The frequency of truncating variants was significantly higher than in the reference cohort (30.3 vs. 21.0%, p = 0.01). Most of the samples (41/68) demonstrated low (or absent) expression of p53, and 17 samples overexpressed p53. LOH was typical for TP53 nonsense variants (14/15). In total, 68/95 samples were LOH positive and showed LOH in all tumorous cells, thus indicating the driver effect of TP53 mutations. Three specimens had KRAS, BAX, APC, and CTNNB1 subclones variants.Conclusion: High frequency of TP53 truncating variants, the low expression of mutant p53, and low incidence of oncogene mutations show potential GOF properties of p53 to be poorly represented in BRCA1/2 associated HGSOC.

Abstract B54: Adipogenic chemokines, body mass index, and ovarian cancer survival

Abstract Objectives: Obesity affects more than one-third of US adults and promotes the development and progression of many cancers. One mechanism by which obesity may influence ovarian cancer is via adipocyte-tumor cell communication, including the production of chemotactic cytokines, or chemokines, in the tumor microenvironment. Our goal was to measure adipogenic chemokine expression and examine associations with body mass index (BMI) and ovarian cancer survival. Methods: We selected 25 chemokines from laboratory experiments that modeled adipogenesis, of which 22 had expression data available for 302 high-grade serous ovarian cancer cases from The Cancer Genome Atlas (TCGA). We measured mRNA expression using Taqman quantitative real-time polymerase chain reaction (QPCR) in 50 high-grade serous tumor samples and ascertained BMI from electronic medical records (EMR) from the Vanderbilt University Medical Center (VUMC). We also evaluated peri-diagnosis BMI (± 4 weeks) from EMR for 298 tumor registry-confirmed (165 serous and 133 nonserous) cases. Expression data were log transformed and dichotomized at median values; associations with disease-free survival (DFS) and overall survival (OS) were quantified using proportional hazards regression. Results: In TCGA analyses, two ligands and one receptor had significant associations with better (CCL8 and CXCL13) and worse (CX3CR1) OS, respectively. Higher CXCL13 expression was also associated with better DFS in VUMC tumors, but significance was attenuated after adjustment for clinical covariates. CX3CR1 was not expressed in all tumors but was positively associated with BMI (Pearson’s r=0.69, P=0.019). Finally, among all 298 tumor registry-confirmed VUMC cases, BMI was not associated with OS, although higher BMI was associated with a 4% significantly increased risk of death among 133 nonserous cases. Conclusions: Our findings suggest that obesity impacts chemokine expression in the tumor microenvironment and ovarian cancer survival. Further, differences between serous and nonserous subtypes may influence the relationship between obesity and ovarian cancer prognosis. Citation Format: Sara Duque, Nneka Anyanwu, George Bukenya, Shriya Karam, Deok-Soo Son, Andrew J. Wilson, Marta A. Crispens, Alicia Beeghly-Fadiel. Adipogenic chemokines, body mass index, and ovarian cancer survival [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 B54.

Digital Immune-Related Gene Expression Signatures In High-Grade Serous Ovarian Carcinoma: Developing Prediction Models For Platinum Response.

PurposeResponse to platinum-based therapy is a major prognostic factor in high-grade serous ovarian cancer (HGSOC). While the exact mechanisms of platinum-resistance remain unclear, evidence is accumulating for a connection between the organism’s immune-response and response to platinum. However, predictive tools are missing. This study was performed to examine the putative role of the genetic tumor immune-microenvironment in mediating differential chemotherapy response in HGSOC patients.Patients and methodsExpression profiling of 770 immune-related genes was performed in tumor tissues from 23 HGSOC cases. Tumors were screened for prognostic and predictive biomarkers using the NanoString nCounter platform for digital gene expression analysis with the appurtenant PanCancer Immune Profiling panel. As validation cohort, gene expression data (RNA Seq) of 303 patients with epithelial ovarian carcinoma (EOC) were retrieved from the The Cancer Genome Atlas (TCGA) database. Different scoring-systems were computed for prediction of risk-of-resistance to cisplatin, disease-free survival (DFS) and overall survival (OS).ResultsValidated on the TCGA-dataset, the developed scores identified 11 significantly differentially expressed genes (p <0.01**) associated with platinum response. HSD11B1 was highly significantly associated with lower risk of recurrence and 7 targets were found highly significantly influencing OS time (p <0.01**).ConclusionOur results suggest that response to platinum-based therapy and DFS in ovarian HGSOC is associated with distinct gene-expression patterns related to the tumor immune-system. We generated predictive scoring systems which proved valid when applied to a set of 303 EOC patients.

Clinical outcomes of postoperative intraperitoneal chemotherapy for patients with early-stage high-grade serous ovarian cancer (HGSC) treated at British Columbia cancer agency.

e17105 Background: Intraperitoneal (IP) chemotherapy has been shown to prolong overall survival in optimally debulked stage III ovarian cancer in randomized trials. In British Columbia, we extrapolated this benefit of IP chemotherapy to early stage HGSC patients for the last 10 years, as these patients are optimally debulked at surgery but still have a high rate of recurrence. We conducted a retrospective study of clinical outcomes associated with IP/IV chemotherapy compared to IV chemotherapy for optimally debulked stage I HGSC cases. Methods: This was a retrospective cohort study of women with stages IA-IC HGSC who had primary surgery between 2007-2015, and received either IV or IP/IV chemotherapy post-operatively. We compared progression-free survival (PFS) and overall survival (OS) outcomes between these 2 groups. Kaplan-Meier method evaluated chemotherapy delivery route with progression free survival (PFS) and overall survival (OS), using the statistical program R. Results: We identified 99 patients; 80 (81%) received IV chemotherapy and 19 (19%) received IP/IV chemotherapy. Among IP/IV cohort, 2/19 (11%) discontinued IP therapy during treatment due to abdominal pain at IP port site or hypersensitivity reaction to IV paclitaxel. 5-year PFS was 88.4% (74.5-100%) and 69.7% (58.7-82.7%) among the IP/IV and IV cohorts, respectively (p = 0.549). There was a trend for higher 5-year OS for the IP/IV group; however, this did not reach statistical significance (100% vs. 71.4%; p = 0.182). Conclusions: In our study, IP/IV chemotherapy for stage I HGSC patients was associated with a trend for higher 5-year PFS and OS compared to IV chemotherapy. This observation warrants further prospective investigation.

Glucocorticoid receptor expression is associated with inferior overall survival independent of BRCA mutation status in ovarian cancer.

High glucocorticoid receptor (GR) protein expression is associated with decreased progression-free survival in ovarian cancer patients and decreased sensitivity to chemotherapy in preclinical models. Prior studies suggest wild type BRCA1 promotes GR activation. The objective of this study was to characterize the relationship of tumor GR gene expression to outcome in ovarian cancer, and to evaluate the relationship of GR expression with BRCA status. Whole exome and whole genome sequencing, gene expression, and clinical data were obtained for high-grade serous ovarian cancers in The Cancer Genome Atlas. Cases with pathogenic somatic or germline BRCA1 or BRCA2 mutations were identified and classified as BRCA mutated. High or low glucocorticoid receptor expression was defined as expression above or below median of the GR/nuclear receptor subfamily 3 C1 (NR3C1) gene level. Overall survival was estimated by the Kaplan-Meier method and compared by Cox regression analysis. Combined germline DNA sequencing and tumor microarray expression data were available for 222 high-grade serous ovarian cancer cases. Among these, 47 had a deleterious germline and/or somatic mutation in BRCA1 or BRCA2. In multivariate analysis, high glucocorticoid receptor gene expression was associated with decreased overall survival among ovarian cancer patients, independently of BRCA mutation status. No correlation of GR/NR3C1 gene expression with BRCA mutation status or BRCA1 or BRCA2 mRNA level was observed. Increased GR gene expression is associated with decreased overall survival in ovarian cancer patients, independently of BRCA mutation status. High-grade serous ovarian cancers with high GR expression and wild type BRCA have a particularly poor outcome.

Pooled Clustering of High-Grade Serous Ovarian Cancer Gene Expression Leads to Novel Consensus Subtypes Associated with Survival and Surgical Outcomes.

Purpose: Here we assess whether molecular subtyping identifies biological features of tumors that correlate with survival and surgical outcomes of high-grade serous ovarian cancer (HGSOC).Experimental Design: Consensus clustering of pooled mRNA expression data from over 2,000 HGSOC cases was used to define molecular subtypes of HGSOCs. This de novo classification scheme was then applied to 381 Mayo Clinic HGSOC patients with detailed survival and surgical outcome information.Results: Five molecular subtypes of HGSOC were identified. In the pooled dataset, three subtypes were largely concordant with prior studies describing proliferative, mesenchymal, and immunoreactive tumors (concordance > 70%), and the group of tumors previously described as differentiated type was segregated into two new types, one of which (anti-mesenchymal) had downregulation of genes that were typically upregulated in the mesenchymal subtype. Molecular subtypes were significantly associated with overall survival (P < 0.001) and with rate of optimal surgical debulking (≤1 cm, P = 1.9E-4) in the pooled dataset. Among stage III-C or IV Mayo Clinic patients, molecular subtypes were also significantly associated with overall survival (P = 0.001), as well as rate of complete surgical debulking (no residual disease; 16% in mesenchymal tumors compared with >28% in other subtypes; P = 0.02).Conclusions: HGSOC tumors may be categorized into five molecular subtypes that associate with overall survival and the extent of residual disease following debulking surgery. Because mesenchymal tumors may have features that were associated with less favorable surgical outcome, molecular subtyping may have future utility in guiding neoadjuvant treatment decisions for women with HGSOC. Clin Cancer Res; 23(15); 4077-85. ©2017 AACR.

Abstract 412: Genetic variation in platinum-sensitive and platinum-resistant high-grade serous epithelial ovarian cancer

Abstract Background: We examined the association of platinum resistance with genetic mutations in high grade serous ovarian cancer (HSOC) patients undergoing high-throughput genomic tumor sequencing. Methods: Snap-frozen and fresh frozen paraffin embedded tissue samples were collected from HSOC patients enrolled on UNCseq (NCT01457196). UNCSeq is an institutional protocol which uses next generation sequencing to detect genetic mutations in a wide array of malignancies. Illumina libraries were prepared separately from tumor and a matched normal sample from each patient. Relevant targets were enriched by a custom designed Agilent SureSelect hybrid capture enrichment library using standard protocols. Samples were sequenced on Illumina HiSeq machines in a variety of formats. Mutations with a quality score &amp;lt;100 were filtered from the data set, and only mutations rated to have a moderate to high impact were retained. Medical record review determined platinum sensitivity or platinum resistance. Tumors were defined as platinum sensitive or resistant if patients were noted to have &amp;gt; or &amp;lt; 6 months of disease free interval following completion of induction therapy, respectively. Results: Overall 39 HSOC cases met inclusion criteria; 32 tumors met criteria for platinum sensitive and 7 platinum resistant. 308 mutations were noted in at least one individual across all patients. The top observed mutations in platinum sensitive HSOC were TP53 (41%, n= 13), GucylA2 (19%, n=6), MLL2 (19%, n=6) and MTOR (16%, n=5). The top observed mutations in platinum resistant tumors were TP53 (71%, n=5), TET1 (43%, n=3), NF1 (43%, n=3) and MLL3 (43%, n=3). There was a trend toward more p53 mutations in resistant tumors (71% versus 41%, p=0.21) There was no difference in the total number of mutations per tumor in platinum sensitive and resistant patients, (3 vs. 4, p=0.516). Conclusions: We did not detect a difference in the number of genetic mutations in HSOC according to platinum sensitivity. Platinum resistant tumors had a trend toward higher frequency of TP53 mutations than platinum sensitive HSOCs. Furthermore, we identified 3 frequently mutated genes in platinum resistant HSOC: TET1, an epigenetic regulator, NF1, a tumor suppressor gene and MLL3, a histone modifier gene. Ongoing tumor sequencing of HSOCs on UNCseq will help to confirm these results. Citation Format: Tara Castellano, Leslie H. Clark, Naim Rashid, Victoria Bae-Jump. Genetic variation in platinum-sensitive and platinum-resistant high-grade serous epithelial ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 412. doi:10.1158/1538-7445.AM2017-412

Control of Tumor Initiation by NKG2D Naturally Expressed on Ovarian Cancer Cells

Cancer cells may co-opt the NKG2D lymphocyte receptor to complement the presence of its ligands for autonomous stimulation of oncogenic signaling. Previous studies raise the possibility that cancer cell NKG2D may induce high malignancy traits, but its full oncogenic impact is unknown. Using epithelial ovarian cancer as model setting, we show here that ex vivo NKG2D+ cancer cells have stem-like capacities, and provide formal in vivo evidence linking NKG2D stimulation with the development and maintenance of these functional states. NKG2D+ ovarian cancer cell populations harbor substantially greater capacities for self-renewing in vitro sphere formation and in vivo tumor initiation in immunodeficient (NOD scid gamma) mice than NKG2D− controls. Sphere formation and tumor initiation are impaired by NKG2D silencing or ligand blockade using antibodies or a newly designed pan ligand-masking NKG2D multimer. In further support of pathophysiological significance, a prospective study of 47 high-grade serous ovarian cancer cases revealed that the odds of disease recurrence were significantly greater and median progression-free survival rates higher among patients with above and below median NKG2D+ cancer cell frequencies, respectively. Collectively, our results define cancer cell NKG2D as an important regulator of tumor initiation in ovarian cancer and presumably other malignancies and thus challenge current efforts in immunotherapy aimed at enhancing NKG2D function.