Stage High-grade Serous Ovarian Cancer Research Articles

Human Fallopian Tube-Derived Organoids with TP53 and RAD51D Mutations Recapitulate an Early Stage High-Grade Serous Ovarian Cancer Phenotype In Vitro.

RAD51D mutations have been implicated in the transformation of normal fallopian tube epithelial (FTE) cells into high-grade serous ovarian cancer (HGSOC), one of the most prevalent and aggressive gynecologic malignancies. Currently, no suitable model exists to elucidate the role of RAD51D in disease initiation and progression. Here, we established organoids from primary human FTE and introduced TP53 as well as RAD51D knockdown to enable the exploration of their mutational impact on FTE lesion generation. We observed that TP53 deletion rescued the adverse effects of RAD51D deletion on the proliferation, stemness, senescence, and apoptosis of FTE organoids. RAD51D deletion impaired the homologous recombination (HR) function and induced G2/M phase arrest, whereas concurrent TP53 deletion mitigated G0/G1 phase arrest and boosted DNA replication when combined with RAD51D mutation. The co-deletion of TP53 and RAD51D downregulated cilia assembly, development, and motility, but upregulated multiple HGSOC-associated pathways, including the IL-17 signaling pathway. IL-17A treatment significantly improved cell viability. TP53 and RAD51D co-deleted organoids exhibited heightened sensitivity to platinum, poly-ADP ribose polymerase inhibitors (PARPi), and cell cycle-related medication. In summary, our research highlighted the use of FTE organoids with RAD51D mutations as an invaluable in vitro platform for the early detection of carcinogenesis, mechanistic exploration, and drug screening.

Lifestyle and personal factors associated with having macroscopic residual disease after ovarian cancer primary cytoreductive surgery

ObjectiveThe presence of macroscopic residual disease after primary cytoreductive surgery (PCS) is an important factor influencing survival for patients with high-grade serous ovarian cancer (HGSC). More research is needed to identify factors associated with having macroscopic residual disease. We analyzed 12 lifestyle and personal exposures known to be related to ovarian cancer risk or inflammation to identify those associated with having residual disease after surgery. MethodsThis analysis used data on 2054 patients with advanced stage HGSC from the Ovarian Cancer Association Consortium. The exposures were body mass index, breastfeeding, oral contraceptive use, depot-medroxyprogesterone acetate use, endometriosis, first-degree family history of ovarian cancer, incomplete pregnancy, menopausal hormone therapy use, menopausal status, parity, smoking, and tubal ligation. Logistic regression models were fit to assess the association between these exposures and having residual disease following PCS. ResultsMenopausal estrogen-only therapy (ET) use was associated with 33% lower odds of having macroscopic residual disease compared to never use (OR = 0.67, 95%CI 0.46–0.97, p = 0.033). Compared to nulliparous women, parous women who did not breastfeed had 36% lower odds of having residual disease (OR = 0.64, 95%CI 0.43–0.94, p = 0.022), while there was no association among parous women who breastfed (OR = 0.90, 95%CI 0.65–1.25, p = 0.53). ConclusionsThe association between ET and having no macroscopic residual disease is plausible given a strong underlying biologic hypothesis between this exposure and diagnosis with HGSC. If this or the parity finding is replicated, these factors could be included in risk stratification models to determine whether HGSC patients should receive PCS or neoadjuvant chemotherapy.

Into the future: A pilot study combining imaging with molecular profiling to predict resectability in ovarian cancer

ObjectiveWe sought to determine the predictive value of combining tumor molecular subtype and computerized tomography (CT) imaging for surgical outcomes after primary cytoreductive surgery in advanced stage high-grade serous ovarian cancer (HGSOC) patients. MethodsWe identified 129 HGSOC patients who underwent pre-operative CT imaging and post-operative tumor mRNA profiling. A continuous CT-score indicative of overall disease burden was defined based on six imaging measurements of anatomic involvement. Molecular subtypes were derived from mRNA profiling of chemo-naïve tumors and classified as mesenchymal (MES) subtype (36%) or non-MES subtype (64%). Fischer exact tests and multivariate logistic regression examined residual disease and surgical complexity. ResultsWomen with higher CT-scores were more likely to have MES subtype tumors (p = 0.014). MES subtypes and a high CT-score were independently predictive of macroscopic disease and high surgical complexity. In multivariate models adjusting for age, stage and American Society of Anesthesiologists (ASA) score, patients with a MES subtype and high CT-score had significantly elevated risk of macroscopic disease (OR = 26.7, 95% CI = [6.42, 187]) and were more likely to undergo high complexity surgery (OR = 9.53, 95% CI = [2.76, 40.6], compared to patients with non-MES tumor and low CT-score. ConclusionPreoperative CT imaging combined with tumor molecular subtyping can identify a subset of women unlikely to have resectable disease and likely to require high complexity surgery. Along with other clinical factors, these may refine predictive scores for resection and assist treatment planning. Investigating methods for pre-surgical molecular subtyping is an important next step.

Abstract 2248: Environmental factors associated with residual disease after ovarian cancer primary cytoreduction surgery

Abstract Background: Ovarian cancer is the deadliest gynecologic cancer. Standard treatments for advanced stage high-grade serous ovarian cancer, the most common type, include (1) primary cytoreductive surgery (PCS) followed by adjuvant chemotherapy or (2) neoadjuvant chemotherapy (NACT) with interval debulking surgery. Patients in whom PCS is unlikely to yield optimal cytoreduction to no visible residual disease (R0) or who have medical contraindications to PCS are recommended to undergo NACT. Previous studies on associations between environmental factors and risk of any macroscopic residual disease have yielded inconsistent results. We aimed to (1) comprehensively examine the associations between demographic, lifestyle and reproductive factors and risk of residual disease after PCS; and (2) develop and internally validate a risk prediction model based on these factors. Methods: We used pooled data on 3,492 women who had PCS following a diagnosis with advanced stage high-grade serous ovarian, fallopian tube or primary peritoneal cancers from the Ovarian Cancer Association Consortium. Fifteen exposures of interest included age at diagnosis, menopausal status, race/ethnicity, education level, first-degree family history of ovarian cancer, endometriosis, smoking, body mass index, parity, incomplete pregnancy, tubal ligation, use of combined oral contraceptives, depot-medroxyprogesterone acetate, estrogen (ET), and combined estrogen-progestin therapy. We fit logistic regression models to examine each exposure-residual disease association in 80% of the data (n=2,794; random selection of participants). We developed a risk prediction model including the factors with p-values ≤0.2. Area under the receiver operating characteristic curve (AUC) was used to assess the model’s discrimination in the remaining 20% of the data (n=698). Results: Of the 3,492 participants, 2,003 (57%) had residual disease following PCS. Older age at diagnosis was associated with an increased risk of residual disease (OR=1.07 per five years, 95% CI 1.03-1.11). In contrast, a family history of ovarian cancer (OR=0.63, 95% CI 0.42-0.95) or ET use for 5+ years (OR=0.61, 95% CI 0.39-0.96) were associated with achieving R0. These above factors were included in the risk prediction model as were race/ethnicity, personal history of endometriosis, and smoking, whose p-values ≤0.2. The model showed modest performance in the validation set (AUC=0.64). Conclusions: Younger age at diagnosis, family history of ovarian cancer, and long-term ET use were associated with achieving R0 following PCS. Future studies incorporating genetic and clinical factors to improve the risk prediction for residual disease following PCS are warranted. Citation Format: Minh Tung Phung, Andrew Berchuck, Ellen L. Goode, Marc T. Goodman, Gillian E. Hanley, Jean Richardson, Bronwyn Grout, Anne Chase, Cindy McKinnon Deurloo, Beth Y. Karlan, Toon Van Gorp, Keitaro Matsuo, Karen McLean, Malcolm C. Pike, Joellen M. Schildkraut, Kathryn L. Terry, Anna DeFazio, Penelope M. Webb, Paul D. P. Pharoah, Susan J. Ramus, Celeste Leigh Pearce. Environmental factors associated with residual disease after ovarian cancer primary cytoreduction surgery [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 2248.

Nerve Anatomy Around Lumbo-aortic Lymphadenectomy by Retroperitoneal Approach

To describe the anatomy of the nerves during a laparoscopic retroperitoneal para-aortic lymphadenectomy with prioritization of their preservation. Demonstration of a nerve-preserving para-aortic lymphadenectomy. A 65-year-old woman with no significant medical history underwent diagnostic laparoscopy for evaluation of a right ovarian mass. In the absence of peritoneal carcinomatosis, bilateral adnexectomy wasperformed with pathology revealing a high-grade tubo-ovarian serous carcinoma. In accordance with French Guidelines for management of ovarian cancer, operative staging including pelvic and para-aortic lymphadenectomy was recommended [1]. Final pathology following staging surgery was consistent with stage IA high-grade serous ovarian cancer prompting administration of adjuvant chemotherapy postoperatively. We performed a lumbo-aortic lymphadenectomy with preservation of the following nerves: the superior hypogastric plexus, the lumbar splanchnic nerves and the sympathetic trunk. Although there are conflicting data as to the benefit of staging lymphadenectomy in women with presumed early stage high-grade serous ovarian cancer, current French Guidelines recommend its performance. When doing so, effort should be made to avoid injury to adjacent normal structures, and in doing so, minimize potential morbidity. The neural structures preserved in this case are part of the sympathetic contingent and participate in the innervation of the abdomen and pelvic viscera. The sympathetic contingent is responsible for the vasomotricity but is also involved in the contraction of the internal genitalia during orgasm and in the inhibition of the peristaltic contractions of the rectum. As such, its preservation may avoid certain postoperative complaints. When possible to do so without compromising essential elements of a cancer surgery, preservation of nerves should be considered.

Neoadjuvant Chemotherapy Induces Genomic and Transcriptomic Changes in Ovarian Cancer.

The growing use of neoadjuvant chemotherapy to treat advanced stage high-grade serous ovarian cancer (HGSOC) creates an opportunity to better understand chemotherapy-induced mutational and gene expression changes. Here we performed a cohort study including 34 patients with advanced stage IIIC or IV HGSOC to assess changes in the tumor genome and transcriptome in women receiving neoadjuvant chemotherapy. RNA sequencing and panel DNA sequencing of 596 cancer-related genes was performed on paired formalin-fixed paraffin-embedded specimens collected before and after chemotherapy, and differentially expressed genes (DEG) and copy-number variations (CNV) in pre- and post-chemotherapy samples were identified. Following tissue and sequencing quality control, the final patient cohort consisted of 32 paired DNA and 20 paired RNA samples. Genomic analysis of paired samples did not reveal any recurrent chemotherapy-induced mutations. Gene expression analyses found that most DEGs were upregulated by chemotherapy, primarily in the chemotherapy-resistant specimens. AP-1 transcription factor family genes (FOS, FOSB, FRA-1) were particularly upregulated in chemotherapy-resistant samples. CNV analysis identified recurrent 11q23.1 amplification, which encompasses SIK2. In vitro, combined treatment with AP-1 or SIK2 inhibitors with carboplatin or paclitaxel demonstrated synergistic effects. These data suggest that AP-1 activity and SIK2 copy-number amplification are induced by chemotherapy and may represent mechanisms by which chemotherapy resistance evolves in HGSOC. AP-1 and SIK2 are druggable targets with available small molecule inhibitors and represent potential targets to circumvent chemotherapy resistance. SIGNIFICANCE: Genomic and transcriptomic analyses identify increased AP-1 activity and SIK2 copy-number amplifications in resistant ovarian cancer following neoadjuvant chemotherapy, uncovering synergistic effects of AP-1 and SIK2 inhibitors with chemotherapy.

Machine Learning-Based Risk Prediction of Critical Care Unit Admission for Advanced Stage High Grade Serous Ovarian Cancer Patients Undergoing Cytoreductive Surgery: The Leeds-Natal Score.

Achieving complete surgical cytoreduction in advanced stage high grade serous ovarian cancer (HGSOC) patients warrants an availability of Critical Care Unit (CCU) beds. Machine Learning (ML) could be helpful in monitoring CCU admissions to improve standards of care. We aimed to improve the accuracy of predicting CCU admission in HGSOC patients by ML algorithms and developed an ML-based predictive score. A cohort of 291 advanced stage HGSOC patients with fully curated data was selected. Several linear and non-linear distances, and quadratic discriminant ML methods, were employed to derive prediction information for CCU admission. When all the variables were included in the model, the prediction accuracies were higher for linear discriminant (0.90) and quadratic discriminant (0.93) methods compared with conventional logistic regression (0.84). Feature selection identified pre-treatment albumin, surgical complexity score, estimated blood loss, operative time, and bowel resection with stoma as the most significant prediction features. The real-time prediction accuracy of the Graphical User Interface CCU calculator reached 95%. Limited, potentially modifiable, mostly intra-operative factors contributing to CCU admission were identified and suggest areas for targeted interventions. The accurate quantification of CCU admission patterns is critical information when counseling patients about peri-operative risks related to their cytoreductive surgery.

Prognostic Significance of SLFN11 Methylation in Plasma Cell-Free DNA in Advanced High-Grade Serous Ovarian Cancer.

Simple SummaryIn the present study, we examined the methylation status of six gene promoters (BRCA1, CST6, MGMT, RASSF10, SLFN11 and USP44) in high-grade serous ovarian cancer (HGSOC). We evaluated the prognostic significance of DNA methylation of these six gene promoters in primary tumors (FFPEs) and plasma cfDNA samples from patients with early, advanced and metastatic HGSOC. We report for the first time that the DNA methylation of SLFN11 in plasma cfDNA was significantly correlated with worse PFS (p = 0.045) in advanced stage HGSOC. Our results strongly indicate that SLFN11 epigenetic inactivation could serve as a potential prognostic DNA methylation biomarker and a predictor of resistance to platinum-based chemotherapy in ovarian cancer.Background: Epigenetic alterations in ctDNA are highly promising as a source of novel potential liquid biopsy biomarkers and comprise a very promising liquid biopsy approach in ovarian cancer, for early diagnosis, prognosis and response to treatment. Methods: In the present study, we examined the methylation status of six gene promoters (BRCA1, CST6, MGMT, RASSF10, SLFN11 and USP44) in high-grade serous ovarian cancer (HGSOC). We evaluated the prognostic significance of DNA methylation of these six gene promoters in primary tumors (FFPEs) and plasma cfDNA samples from patients with early, advanced and metastatic HGSOC. Results: We report for the first time that the DNA methylation of SLFN11 in plasma cfDNA was significantly correlated with worse PFS (p = 0.045) in advanced stage HGSOC. Conclusions: Our results strongly indicate that SLFN11 epigenetic inactivation could be a predictor of resistance to platinum drugs in ovarian cancer. Our results should be further validated in studies based on a larger cohort of patients, in order to further explore whether the DNA methylation of SLFN11 promoter could serve as a potential prognostic DNA methylation biomarker and a predictor of resistance to platinum-based chemotherapy in ovarian cancer.

Survival Is Related to Estrogen Signal Transduction Pathway Activity in Postmenopausal Women Diagnosed with High-Grade Serous Ovarian Carcinoma.

Simple SummaryAll cells have a complex internal network of ‘communication chains’ called signal transduction pathways (STPs). Through interaction of different proteins in STPs, they are partly responsible for the behavior of a cell. In our study, we investigated the activity of six STPs in 85 women with advanced stage high-grade serous ovarian cancer (HGSC). To investigate the relation between and differences in survival and STP activity, women with a short disease-free survival (below 12 months) and a long disease-free survival (above 24 months) were included. We found no differences in mean STP activity between short-term survivors (52 women) and long-term survivors (33 women). However, when we analyzed postmenopausal women, we found that both disease-free and overall survival were related to estrogen receptor (ER) pathway signaling. This indicates that a better survival outcome was related to a more active ER pathway in this subgroup.High-grade serous ovarian carcinoma (HGSC), the most common subtype of ovarian cancer, has a high mortality rate. Although there are some factors associated with survival, such as stage of disease, there are remarkable differences in survival among women diagnosed with advanced stage disease. In this study, we investigate possible relations between survival and signal transduction pathway (STP) activity. We assessed the functional activity of the androgen receptor (AR), estrogen receptor (ER), phosphoinositide-3-kinase (PI3K), Hedgehog (HH), transforming growth factor beta (TGF-β) and canonical wingless-type MMTV integration site (Wnt) pathway in 85 primary tumor samples of patients with FIGO stage IIIC to IVB HGSC and disease-free survival (DFS) below 12 (n = 52) or over 24 months (n = 33). There were no significant differences in median pathway activity between patients with a short and long DFS. In univariate Cox proportional hazards analysis, ER pathway activity was related to a favorable DFS and overall survival (OS) in postmenopausal women (p = 0.033 and p = 0.041, respectively), but not in premenopausal women. We divided the postmenopausal group into subgroups based on ER pathway activity quartiles. Survival analysis revealed that postmenopausal women in the lowest ER quartile had a shorter DFS and OS (log-rank p = 0.006 and p < 0.001, respectively). Furthermore, we were able to form subgroups of patients based on an inverse relation between ER and PI3K pathway activity. In conclusion, in postmenopausal patients with advanced stage HGSC, a poorer survival outcome was associated with low functional ER pathway activity.

Neoadjuvant treatment as a window to chemotherapy driven alterations to the genome and transcriptome of high-grade serous ovarian cancer

<h3>Objectives:</h3> The growing use of neoadjuvant chemotherapy to treat advanced stage high-grade serous ovarian cancer (HGSOC) creates an opportunity to better understand chemotherapy-induced mutational and gene expression changes. A tumor's response to chemotherapy may provide prognostic information or allow prediction of future response to therapy. We performed a cohort study to assess changes in the tumor genome and transcriptome in women receiving neoadjuvant chemotherapy and explored the role of the AP-1 pathway on chemotherapy response. <h3>Methods:</h3> In our single-institution study, we included 50 patients with stage IIIC or IV HGSOC who received neoadjuvant chemotherapy and had archived pre- and post-chemotherapy tumor samples. We performed whole exome RNA-sequencing and panel sequencing of 596 cancer-related genes from FFPE specimens. Significantly differentially expressed genes (DEGs) between pre- and post-chemotherapy samples were identified using paired statistical analysis (GFOLD). An AP-1 inhibitor, SR 11302, was used to explore the in vitro role of AP-1 signaling on chemotherapy response. <h3>Results:</h3> Following tissue and sequencing quality control, the final patient cohort consisted of a total of 32 paired DNA and 20 paired RNA samples from pre- and post-neoadjuvant chemotherapy. Eighteen patients within the cohort had both DNA and RNA available. Mutations in <i>TP53</i> were identified in 31/32 patients. There was a shift in mutational class after chemotherapy from C>G to C>T (p=0.035). Gene expression analyses found that most DEGs were upregulated by chemotherapy, primarily in the chemotherapy resistant specimens. Several genes were solely upregulated in chemotherapy resistant patients, including AP-1 transcription factor family genes (FOS, FOSB, FRA-1), genes implicated in chemotherapy resistance (DUSP1, SERPINE1, MEOX2, ERRFI1), and genes previously associated with cell survival (CCL14, HAS1, NR4A1). The in vitro role of AP-1 was demonstrated by observing an increase in c-Jun expression after treatment with paclitaxel, but not carboplatin. Combining paclitaxel or carboplatin with SR 11302 decreased the IC50 of both therapies. Pairing these therapies additionally demonstrated synergistic effects with a favorable combination index of <1, at effect sizes >75% for paclitaxel and >90% for carboplatin. Additionally, favorable drug dose reduction indices were found at large effect sizes. These observations were most pronounced with the SR 11302 and paclitaxel combination. <h3>Conclusions:</h3> Genomic analysis of tumors before and after chemotherapy did not reveal any consistent mutations associated with chemotherapy response. Gene expression analysis suggested a link between upregulation of the AP-1 pathway in chemotherapy resistant patients after treatment. In vitro experiments indicated that AP-1 inhibition synergizes with standard cytotoxic agents, particularly paclitaxel, and might be a novel approach to overcome or delay paclitaxel resistance in HGSOC.

Abstract 103: Spatially resolved transcriptomics identified distinct tumor-stroma crosstalk networks in long term ovarian cancer survivors

Abstract The tumor microenvironment (TME), composed primarily of fibroblasts, endothelial cells, lymphocytic infiltrates and extracellular matrix proteins, can directly affect cancer cell growth, migration, differentiation as well as immune cell landscapes, thereby presenting a unique aspect of diagnosing and treating cancer. Cancer-associated fibroblasts (CAF) and immune cells are the main orchestrators of the ovarian cancer TME. We hypothesized that spatial transcriptomics (ST), which can provide a rich spatial context to gene expression, will identify crosstalk signaling networks among various cell types in the ovarian TME. Advanced stage high-grade serous ovarian cancer (HGSC) tissue frozen sections from two treatment naïve long-term survivors (LTS, overall survival ≥ 10 years) and two short-term survivors (STS, overall survival ≤ 2 years) were placed onto a ST expression slide pre-spotted with 1000 unique barcoded RNA-capturing probes. The ST slides were then stained with H&amp;E and imaged. Tissue permeabilization and cDNA synthesis were then performed directly on the tissue section. The derived barcoded cDNA libraries from each sample were sequenced using Illumina NextSeq500 flow cells. After RNA-Seq analysis, supervised analysis was then performed by selecting different regions (based on tissue histology) in the tumor, tumor/stroma mixture, stroma close or far away from tumor areas to identify differentially expressed genes between STS and LTS. Stromal cells from different spatial locations had unique differentially expressed genes based on their proximity (11 genes in LTS; 11 genes in STS) or remoteness (18 genes in LTS; 10 genes in STS) to cancer cell compartments. Among the major modulated gene networks, higher levels of antigen-presenting molecules were found in the stroma in close proximity to the tumor cell nest than in stroma located far away in LTS tumor samples but not in the STS samples, suggesting an increased number of activated antigen-presenting cells in LTS tumors. In addition, higher levels of adhesion molecules and angiogenetic factors were found in the stroma in close proximity to the tumor cell nest than in stroma located far away in STS tumor samples but not in LTS samples, suggesting that adhesion molecules and angiogenetic factors produced by stromal cells may facilitate the invasiveness of the tumor cells, which subsequently leads to short term survival in patients with the disease. Our findings demonstrate for the first time that spatially resolved transcriptomics allows the identification of prognostic biomarkers associated with overall survival in HGSC patients. Further studies using deconvoluted ST data to further delineate the specific stromal cell subtypes in close proximity to tumors, and imaging mass cytometry (IMC) or multiplexed immunohistochemistry to validate the protein expression of the potential biomarkers are ongoing. Citation Format: Sammy Ferri-Borgogno, Jianting Sheng, Ying Zhu, Kwong K. Wong, Stephen T. Wong, Samuel C. Mok. Spatially resolved transcriptomics identified distinct tumor-stroma crosstalk networks in long term ovarian cancer survivors [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 103.

Abstract 1440: Novel imipridone ONC206 suppresses ovarian cancer progression through modulating immune cell response

Abstract Advanced ovarian cancer (stages III and IV) is the most lethal gynecologic malignancy in the United States. Survival of this cancer has not improved to a major extent over the past decade. High-grade serous ovarian cancer (HGSC), in particular, is notable for its initial sensitivity to chemotherapy using platinum and taxane combination following debulking surgery. However, the vast majority of these cancers (&amp;gt;75-80%) recur within 12-24 months after diagnosis, and patients die of progressively chemotherapy-resistant disease. The identification of prognostic or predictive markers, for ovarian cancer is crucial to the development of therapeutic targets and thus improvement of survival. ONC201 is the first clinical bitopic antagonist of dopamine receptor D2 (DRD2), that is well tolerated and currently being investigated in several clinical trials for oncology. ONC206 is a chemical derivative of ONC201 with the same impridone core structure, which is also a DRD2 antagonist that exhibits distinct receptor pharmacology and nanomolar potency in various preclinical cancer models. However, the effects of ONC206 on HGSC progression and the mechanism of action have not been thoroughly explored. Preliminary data demonstrated that overexpression of DRD2 is associated with poor overall survival rates in patients with advanced stage HGSC. ONC206-treated HGSC cells demonstrated significantly lower growth rates and higher percentage of apoptotic cells than ONC201-treated cells did in vitro. Besides, intraperitoneal injection of ONC206 (100 mg/kg) twice a week into HGSC-bearing immunocompetent mice demonstrated decreased tumor volume in vivo. In addition, by using suspension mass cytometry with a panel of 28 antibodies, fresh tumor tissues from ONC206-treated mice showed markedly increase in intratumoral NK cells and activated CD8+ T cells densities. These data suggest that ONC206 is more potent than ONC201 in suppressing HGSC growth directly. In addition, ONC206 may also suppresses HGSC growth through activating immune cell response in tumor tissues. Further studies that define the molecular mechanism by which DRD2 modulates the tumor suppressive effect of ONC206 on HGSC cells by suppressing HGSC directly or enhancing anti-tumor immune cell activity will be perform to establish ONC206 as a novel therapeutic agent in treatment of HGSC patients. Citation Format: Chi Lam Au Yeung, Wen Hu, Sammy Ferri-Borgogno, Rohinton S. Tarapore, Joshua E. Allen, Karen H. Lu, Samuel C. Mok. Novel imipridone ONC206 suppresses ovarian cancer progression through modulating immune cell response [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 1440.

SOX2 is a promising predictor of relapse and death in advanced stage high-grade serous ovarian cancer patients with residual disease after debulking surgery

ABSTRACT The transcription factor SOX2 is a well-established and important stem cell marker. Its role in cancer biology remains unclear, but it has been proposed to also be a marker of cancer stem cells. We investigated the role of SOX2 protein expression in women with high-grade serous ovarian cancer (HGSOC) to determine its potential prognostic and treatment predictive value. We constructed a tissue microarray of 130 advanced stage HGSOC tumors with an average of 6 cores each, stained for SOX2 protein expression and evaluated survival outcomes. We also treated two HGSOC cell lines with carboplatin and paclitaxel and measured SOX2 expression by RT-PCR and immunoblotting at different doses and time-points. Among patients with non-radical debulking surgery overall and progression-free survival were shorter for patients with SOX2 positive tumors (mean 26 vs. 39 months, log-rank test: p = .0076, and mean 14 vs. 19 months, p = .055, respectively). Knockdown of SOX2 in cell lines did not affect growth inhibition following chemotherapy treatment. Our results show that SOX2 has a strong prognostic potential among HGSOC patients with residual tumor tissue after debulking surgery and suggest that SOX2 expressing cells remaining after non-radical debulking surgery may constitute a subpopulation of cancer stem cells with greater tumor-initiating potential.

Evaluation of paraneoplastic antigens reveals TRIM21 autoantibodies as biomarker for early detection of ovarian cancer in combination with autoantibodies to NY-ESO-1 and TP53.

The majority of ovarian cancer cases are diagnosed at an advanced stage with poor prognosis. This study evaluates autoantibodies against tumor antigens to identify candidate biomarkers for early detection of ovarian cancer in women at increased risk. To assess the immunoreactivity of paraneoplastic antigens and tumor associated antigens with high-grade serous ovarian cancer (HGSOC) samples. Five paraneoplastic antigens along with three tumor-associated antigens were evaluated with HGSOC patient serum samples. Validation screening was performed with n= 164 serum samples consisting of: 50 late stage HGSOC, 14 early stage HGSOC, 50 benign ovarian cyst, and 50 healthy control samples on ELISA and western blot. The four markers TRIM21, NY-ESO-1, TP53, and PAX8 were evaluated on a second validation serum set, n= 150. TRIM21 achieved the highest sensitivity in the first validation screening of 33% with 100% specificity. Combining TRIM21 with NY-ESO-1, TP53, and PAX8 provided 67% sensitivity with 94% specificity, and 56% sensitivity at 98% specificity. These four markers resulted in 46% sensitivity with 98% specificity in the second validation cohort; TRIM21 achieved the highest individual sensitivity of 36%. Autoantibodies to TRIM21, NY-ESO-1, and TP53 may complement CA125 in screening of women at genetic risk for ovarian cancer.

Prediction of Platinum-based Chemotherapy Response in Advanced High-grade Serous Ovarian Cancer: ADC Histogram Analysis of Primary Tumors

To investigate the feasibility of apparent diffusion coefficient (ADC) histogram analysis of primary advanced high-grade serous ovarian cancer (HGSOC) to predict patient response to platinum-based chemotherapy. A total of 70 patients with 102 advanced stage HGSOCs (International Federation of Gynecology and Obstetrics (FIGO) stages III-IV) who received standard treatment of primary debulking surgery followed by the first line of platinum-based chemotherapy were retrospectively enrolled. Patients were grouped as platinum-resistant and platinum-sensitive according to whether relapse occurred within 6 months. Clinical characteristics, including age, pretherapy CA125 level, International Federation of Gynecology and Obstetrics stage, residual tumor, and histogram parameters derived from whole tumor and solid component such as ADCmean; 10th, 20th, 25th, 30th, 40th, 50th, 60th, 70th, 75th, 80th, 90th percentiles; skewness and kurtosis, were compared between platinum-resistant and platinum-sensitive groups. No significantly different clinical characteristics were observed between platinum-sensitive and platinum-resistant patients. There were no significant differences in any whole-tumor histogram-derived parameters between the two groups. Significantly higher ADCmean and percentiles and significantly lower skewness and kurtosis from the solid-component histogram parameters were observed in the platinum-sensitive group when compared with the platinum-resistant group. ADCmean, skewness and kurtosis showed moderate prediction performances, with areas under the curve of 0.667, 0.733 and 0.616, respectively. Skewness was an independent risk factor for platinum resistance. Pretreatment ADC histogram analysis of primary tumors has the potential to allow prediction of response to platinum-based chemotherapy in patients with advanced HGSOC.

Abstract TMIM-067: EXPRESSION OF LNCRNAS IN OVARIAN CANCER-ASSOCIATED FIBROBLASTS IS ASSOCIATED WITH PATIENT SURVIVAL

Abstract BACKGROUND: Ovarian cancer is the most lethal gynecological malignancy in women, with high-grade serous ovarian cancer (HGSOC) the most common and aggressive subtype. The tumor microenvironment is acknowledged to play a vital role in the growth and metastasis of many solid tumors, including ovarian cancer, and as such represents an attractive new therapeutic target. In ovarian cancer, patients with a higher proportion of desmoplasia have a poorer survival. Cancer-associated fibroblasts (CAFs) represent the most abundant cell type in the tumor stroma and are responsible for producing the desmoplastic reaction that is a poor prognostic factor in HGSOC. Genetic aberrations in ovarian CAFs are extremely rare, raising the possibility of alternative mechanisms that regulate gene expression in CAFs, such as regulation by long non-coding RNAs (lncRNAs). LncRNAs are transcripts that do not encode for protein, but have been shown to play important roles in several diseases, including cancer. However, very little is known about the role of lncRNAs in the tumor microenvironment. OBJECTIVES: To identify lncRNAs whose expression levels in CAFs are associated with patient survival and use computational approaches to predict their function. METHODS: CAFs were laser capture microdissected from 67 advanced stage HGSOCs. RNA was extracted from the microdissected samples and expression analyzed using Affymetrix U133 Plus 2.0 Arrays. Probes identified as lncRNAs were used in this analysis. Samples were normalized and background corrected using the robust multiarray average (RMA) method and expression values were log2 transformed. Expression levels of each lncRNA were clustered into low and high expression groups. Kaplan Meier /log-rank analysis was used to assess the association between expression levels of each lncRNA and the patients' overall survival. Multivariate cox regression analysis was used to determine if differential expression of lncRNAs were independent predictors of survival. A network based ‘guilt-by-association' approach was used to predict the function of lncRNAs associated with patient survival. RESULTS: Increased expression of 9 lncRNAs including DANCR, MALAT1 and NEAT1 and decreased expression of 1 lncRNA in ovarian CAFs were found to be associated with poorer overall survival by the log-rank test. Expression profiles of 5 lncRNAs as well as response to chemotherapy and debulking status were significant predictors of survival by univariate cox proportional hazards analysis. To adjust for existing collinearity of the 10 lncRNAs, the first principal component of these lncRNAs (capturing 98% of variations), as well as response to chemotherapy and debulking status were incorporated into a multivariate model. The first principal component (HR=0.74, P=0.0001163) and response to chemotherapy (HR=0.22, P=0.000168) were found to be independent predictors of survival. Functional enrichment analysis revealed these lncRNAs are likely to play a role in metabolism, autophagy or immune response. CONCLUSIONS: We have identified several lncRNAs whose expression levels in CAFs are associated with survival of HGSOC patients, raising the likelihood that they play an important role in the tumor-promoting functions of CAFs. A further understanding of the role of lncRNAs in CAFs may be useful when designing novel therapies that target the tumor microenvironment. Citation Format: Emily K. Colvin, Viive M. Howell, Samuel C. Mok, Goli Samimi and Fatemeh Vafaee. EXPRESSION OF LNCRNAS IN OVARIAN CANCER-ASSOCIATED FIBROBLASTS IS ASSOCIATED WITH PATIENT SURVIVAL [abstract]. In: Proceedings of the 12th Biennial Ovarian Cancer Research Symposium; Sep 13-15, 2018; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2019;25(22 Suppl):Abstract nr TMIM-067.

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.

Mesenchymal molecular subtype is an independent predictor of severe postoperative complications after primary debulking surgery for advanced ovarian cancer

ObjectiveTo evaluate the contribution of molecular subtype to 30-day postoperative complications and 90-day mortality after primary debulking surgery (PDS) in advanced stage high-grade serous ovarian cancer (HGSOC). MethodsPatients with stages III–IV HGSOC undergoing PDS from 1994 to 2011 with available molecular subtyping were included. Residual disease (RD) status was categorized as 0, 0.1–0.5, 0.6–1.0, or >1 cm. Surgical complexity scores were calculated as high, intermediate, or low as previously published. Postoperative complications were graded according to the modified Accordion classification 0–4 scale; severe was defined as grade ≥3. Molecular subtypes were derived from Agilent 4 × 44k tumor mRNA expression profiles and categorized as mesenchymal (MES) or non-mesenchymal (non-MES). Logistic regression modeling was used to assess associations. ResultsOf 329 patients, 68.7% were stage IIIC, 80.5% had RD ≤1 cm, 28.0% had MES subtype, and 19.5% had a grade 3–4 complication; 90-day mortality was 5.8%. In univariate analysis, patients with MES subtype were more likely to have severe complications compared to non-MES (31.5 vs. 14.8%; OR 2.66, 95% CI 1.51–4.69; p < 0.001). MES subtype remained an independent predictor of complications (adjusted OR 2.14, 95% CI 1.17–3.92; p = 0.01) in a multivariable model which included ASA score, preoperative albumin, and surgical complexity. There was no statistical difference in 90-day mortality in patients with MES compared to non-MES subtype (7.6 vs. 5.1%; OR 1.54, 95% CI 0.59–4.05; p = 0.38). ConclusionsMES subtype is an independent predictor of severe postoperative morbidity and adds to the potential use of pre-operative molecular testing in planning primary treatment of patients with advanced ovarian cancer.

Potential risk factors associated with prognosis of neoadjuvant chemotherapy followed by interval debulking surgery in stage IIIc-IV high-grade serous ovarian carcinoma patients.

No consensus has been achieved on the prognostic factors for patients with advanced stage epithelial ovarian cancer who underwent neoadjuvant chemotherapy (NAC) followed by interval debulking surgery (IDS). This study aimed to investigate the prognostic factors for the patients diagnosed as International Federation of Gynecology and Obstetrics stage IIIc-IV high-grade serous ovarian cancer (HG-SOC). A total of 200 patients histologically diagnosed as IIIc-IV stage HG-SOC were retrospectively analyzed. All patients underwent platinum-NAC followed by IDS treatment between January 2003 and December 2013. The potential predictive factors (including preoperative ascites volume, cancer antigen 125 [CA-125] and CA-125 decreasing kinetics, NAC and adjuvant chemotherapy cycle number as well as tumor characteristics) for optimal cytoreduction by IDS and for progression free survival (PFS) and overall survival (OS) were assessed. Optimal cytoreduction by IDS was achieved in 78% of HG-SOC patients who underwent NAC. The median number of NAC cycle was 3 (range 1-8). No ascites regression (P < 0.01, odds ratio [OR] = 2.28, 95% confidence interval [CI]: 1.41-3.69), and worse CA-125 decreasing kinetics (P < 0.01, OR = 2.01, 95% CI: 1.37-2.93) were independent predictive factors for suboptimal cytoreduction by IDS. Multivariate regression analysis revealed that PFS and OS were independently associated with preoperative ascites (P < 0.01, hazard ratio [HR] = 2.13, 95% CI: 1.38-3.28 and P < 0.01, HR = 2.33, 95% CI: 1.27-4.26, respectively) and CA-125 decreasing kinetics (P = 0.01, HR = 1.10, 95% CI: 1.02-1.18 and P < 0.01, HR = 1.22, 95% CI: 1.08-1.37, respectively). PFS of patients who underwent more than four NAC cycles was shorter than those of patients who received four or less number of NAC cycles; however, no difference was observed for OS. Ascites regression and CA-125 decreasing kinetics were independently associated with the optimal cytoreduction rate and survival of patients diagnosed with advanced stage HG-SOC and treated with NAC/IDS.

Abstract 5408: Elevated level of serum miR-1290 is correlated with high-grade serous ovarian epithelial ovarian cancer and might be a potential biomarker

Abstract Objective: There is a critical need for improved diagnostic markers to detect ovarian high grade serous ovarian cancer (HGSOC). MicroRNAs (miRNAs) stably exist in circulating blood, reflecting tissue or organ conditions and present in circulating microvesicles such as exosomes. Recent studies have confirmed the potential use of miRNAs profiling as a novel non-invasive biomarker for diagnosis of HGSOCs. The aim of this study is to identify which miRNAs are highly produced from HGSOCs and analyze whether serum miRNA can discriminate patients with HGSOC from healthy controls. Methods: Secreted exosomes from ovarian cancer cell lines were collected and exosomal miRNAs extracted. miRNA microarray was performed and several elevated miRNAs specific to HGSOCs were picked up. Among these, we focused on miR-1290. Serum from 71 pre-operative, 46 post-operative ovarian cancer patients and 13 healthy controls were gathered and its expression levels were detected by quantitative Real Time PCR. Results: In HGSOC patients, miR-1290 emerged overexpressed compared to healthy controls (3.52-fold). ROC analysis showed that at the cut-off of 1.61(healthy controls ; 1), the sensitivity and specificity were 63 % and 85 % respectively for detecting HGSOC (AUC = 0.71). The AUC of CA125 + miR-1290 combination was 1.00. Its expression singnificantly decreased after operation(5.87 → 1.17 ; P &amp;lt; 0.01). In advanced stage HGSOC patients, moreover, it expressed marginally higher than early stage ones(4.23 VS 1.58 ; P = 0.23). Conclusions: Serum miR-1290 can be a potential diagnostic biomarker for HGSOC. Citation Format: Masaki Kobayashi, Sawada Kenjiro, Yoshimura Akihiko, Miyamoto Mayuko, Nakatsuka Erika, Kodama Michiko, Hashimoto Kae, Mabuchi Seiji, Kimura Tadashi. Elevated level of serum miR-1290 is correlated with high-grade serous ovarian epithelial ovarian cancer and might be a potential biomarker [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5408.