High Ovarian Cancer Research Articles

Abstract A078: In vivo tumor micro-environment characterization: preliminary results of an ovarian cancer patients-derived co-colture organoids platform

Abstract Introduction: Most patients with ovarian cancer (OC) are diagnosed at advanced stage. Current standard of care is based on surgery and platinum-based chemotherapy (CHT) in association with target therapies according to molecular characteristics (BRCA status and Homologous Recombination Repair (HRR) status). However, 15-20% progressed to first line CHT and mechanisms of resistance remain far from being completely known. In this scenario the role of tumoral microenvironment (TME) represents an open question. Methods: We designed a study to establish OC patients-derived co-colture organoids (ID PICTURE, IRB approval 4531). Both peripheral Blood Mononuclear Cells (PBMC) and isolated immune infiltrating cells from tumor tissue were planned to be used. The first endpoint of the study was the feasibility of this approach including (i) establishment OC patients-derived organoids (ii) PBMC isolation from whole blood and characterization (iii) immune infiltrate isolation from tumor tissue and characterization. For the latter, the evaluation of the immune phenotype was carried out by cytofluorimetry analyses, through target cells labelling with monoclonal antibodies conjugates with fluorescent molecules (CD45, CD19, CD3, CD4, CD8, 7AAD). Correlation between tumor immune infiltrate and mutational and clinical findings was also accomplished. Results: From January 2022 to May 2023, 36 patients with EOC, 92% with high grade serous OC and 95% with an advanced stage (from stage III according to FIGO, all high tumor load according to the Fagotti’s score) were enrolled. 23 patients (64%) were BRCA wild type while HRR status was available only for 17 patients of whom 28% were deficient. Considering the model feasibility, 5 organoids were obtained, and 8 and 20 million immune cells were isolated from tissue and peripheral blood, respectively. The immune infiltrate analysis was performed on 21 samples obtained from primary debulking surgery and 15 from diagnostic laparoscopies. 75% were treated with carboplatin paclitaxel (weekly or q21); among patients undergoing neoadjuvant treatment, 3 had a complete response (CRS3). The infiltration of B and T lymphocytes was described in all patients: 73% were positive for CD3, 20% for CD45, 7% for CD19. The lymphocytes T characterization was available for 7 patients with a median value of CD4+ 51.3, CD8+ 44.4, CD8+CD4+ 2,6 and CD8-CD4- 1.6. A trend for statistically significant difference was observed for CD45+ in stage IV vs stage I-III (p=0.021) and in CD19+ B cells in BRCA mutant vs BRCA WT (p=0.026). Finally, CD3+ T cells showed a significantly higher concentration in the 4 patients experiencing progression of disease at 6 months follow-up (p=0.014). Conclusion: These preliminary results suggest that patients-derived organoids co-cultured with tumor immune infiltrate could be challenging because of small numbers of overall cell content. Nevertheless, a correlation between specific components of B and T cells and molecular features and cancer progression deserves further investigation. Citation Format: Floriana Camarda, Clara Di Mario, Camilla Nero, Barbara Tolusso, Stefano Alivernini, Francesca Sillano, Sonia Mastrogiovanni, Tina Pasciuto, Elisa Gremese, Eleonora Cesari, Alessandra Ciucci, Claudio Sette, Giovanni Scambia. In vivo tumor micro-environment characterization: preliminary results of an ovarian cancer patients-derived co-colture organoids platform [abstract]. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_2):Abstract nr A078.

Abstract C058: Clinical relevance of telomerase upregulation via TERT promoter mutation or TERC amplification in high-grade ovarian cancer

Abstract Background: Increased telomerase activity confers a survival advantage to cancer cells and is considered one of the cancer hallmarks. The two main molecular mechanisms responsible for telomerase upregulation are the amplification of the telomerase RNA component gene (TERCamp) which serves as the template for telomeric repeats, and mutations in the telomerase reverse transcriptasegene promoter (TERTm), which encored the catalytic unit of telomerase. Increased telomerase activity has been detected in more than 90% of ovarian cancer (OC) but the clinical impact of this phenotype remains understudied. Methods: This retrospective analysis included all patients (pts) with high grade OC who underwent large-panel sequencing (Foundation Medicine) from National University Cancer Institute, Singapore and Institut Gustave Roussy, France. TERTm and TERCamp were correlated with clinical, pathological and molecular features as well as progression-free survival (PFS, calculated from histological diagnosis to first progression). Results: Out of the 503 pts with OC analyzed, 15 pts (3.0%) presented TERT mutation and 39 pts (7.8%) had TERC amplification. In the TERTm subgroup, only one hotspot mutation was detected (c.-124C>T). Compared to the wild-type (WT) group, there was significantly higher frequency of FIGO I/II diseases (57% vs 17%, p=0.001) and clear-cell histology (80% vs 14%, p<0.001). Consequently, there were more ARID1A and PIK3CA mutations and median loss of heterozygosity (LOH) score was significantly lower (5.3% vs 16.4%, p=0.006). Interestingly, TERTm were exclusive to P53 and BRCA1/2 mutations. With a follow-up of 64 months, the median PFS was 8.1 months, 18.7 months and 25.5 months for the TERTm, P53m and WT subgroups respectively (p=0.006). In the multivariate analysis, TERTm emerged as an independent negative prognostic biomarker. In the TERCamp subgroup, compared to WT, there was no difference in term of stage (74% of advanced stages vs 82%), or histologic type (77% of high-grade serous vs 71%). TERCamp was associated with a significantly higher tumor mutational load (6.2 mut/mbase vs 4.2, p<0.001), more P53 mutations (90% vs 72%, p=0.014), more BRCA1/2 mutations (33% vs 17%, p=0.016) and higher LOH (22% vs 15%, p=0.023). There were no statistical differences in terms of PFS. Conclusion: This study highlights intriguing heterogeneity in high-grade OC pts with telomerase upregulation. TERTm are associated with a clear-cell phenotype and TERTm and P53m define three prognostic subgroups among OC patients. On the other hand, TERCamp are detected in genomically unstable tumors presenting a higher mutational burden and copy-number alterations. These results emphasize the critical importance of the molecular mechanism underlying increased telomerase activity, which may impact the efficacy of telomerase-targeted therapy. Citation Format: Felix Blanc-Durand, Natalie Ngoi, Damien Vasseur, Patricia Pautier, Judith Michels, Kaissa Ouali, Catherine Genestie, Sophie Cotteret, Etenne Rouleau, Yi Wan Lim, Siew Eng Lim, Diana Lim, Silvana Talisa Wijaya, Alexandra Leary, David SP Tan. Clinical relevance of telomerase upregulation via TERT promoter mutation or TERC amplification in high-grade ovarian cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C058.

Pathogenic germline variants in SMARCA4 and further cancer predisposition genes in early onset ovarian cancer.

To assess the role of germline pathogenic variants (PVs) in SMARCA4 and further established ovarian cancer (OC) predisposition genes in early onset OC, we investigated a clinical cohort of 206 unrelated OC index patients with an age at diagnosis of OC ≤40 years using an extended panel of 24 (candidate) cancer predisposition genes. PVs in established OC predisposition genes were most frequent in patients with high grade serous OC (21/62, 33.9%), comparatively rare in patients with epithelial OC other than high grade serous (5/74, 6.8%) or borderline ovarian tumours (2/39, 5.1%) and absent in mucinous OC (0/27). We demonstrate that germline PVs in SMARCA4 unlikely predispose for early onset OC other than SCCOHT.

Ovarian Cancer and Parkinson's Disease: A Bidirectional Mendelian Randomization Study.

(1) Background: Ovarian cancer (OC) and Parkinson's disease (PD) represent a huge public health burden. The relationship of these two diseases is suggested in the literature while not fully understood. To better understand this relationship, we conducted a bidirectional Mendelian ran-domization analysis using genetic markers as a proxy. (2) Methods: Utilizing single nucleotide polymorphisms associated with PD risk, we assessed the association between genetically predicted PD and OC risk, overall and by histotypes, using summary statistics from previously conducted genome-wide association studies of OC within the Ovarian Cancer Association Consortium. Similarly, we assessed the association between genetically predicted OC and PD risk. The inverse variance weighted method was used as the main method to estimate odds ratios (OR) and 95% confidence intervals (CI) for the associations of interest. (3) Results: There was no significant association between genetically predicted PD and OC risk: OR = 0.95 (95% CI: 0.88-1.03), or between genetically predicted OC and PD risk: OR = 0.80 (95% CI: 0.61-1.06). On the other hand, when examined by histotypes, a suggestive inverse association was observed between genetically predicted high grade serous OC and PD risk: OR = 0.91 (95% CI: 0.84-0.99). (4) Conclusions: Overall, our study did not observe a strong genetic association between PD and OC, but the observed potential association between high grade serous OC and reduced PD risk warrants further investigation.

Precision gynecologic oncology: circulating cell free DNA epigenomic analysis, artificial intelligence and the accurate detection of ovarian cancer

Ovarian cancer (OC) is the most lethal gynecologic cancer due primarily to its asymptomatic nature and late stage at diagnosis. The development of non-invasive markers is an urgent priority. We report the accurate detection of epithelial OC using Artificial Intelligence (AI) and genome-wide epigenetic analysis of circulating cell free tumor DNA (cfTDNA). In a prospective study, we performed genome-wide DNA methylation profiling of cytosine (CpG) markers. Both conventional logistic regression and six AI platforms were used for OC detection. Further, we performed Gene Set Enrichment Analysis (GSEA) analysis to elucidate the molecular pathogenesis of OC. A total of 179,238 CpGs were significantly differentially methylated (FDR p-value < 0.05) genome-wide in OC. High OC diagnostic accuracies were achieved. Conventional logistic regression achieved an area under the ROC curve (AUC) [95% CI] 0.99 [± 0.1] with 95% sensitivity and 100% specificity. Multiple AI platforms each achieved high diagnostic accuracies (AUC = 0.99–1.00). For example, for Deep Learning (DL)/AI AUC = 1.00, sensitivity = 100% and 88% specificity. In terms of OC pathogenesis: GSEA analysis identified ‘Adipogenesis’ and ‘retinoblastoma gene in cancer’ as the top perturbed molecular pathway in OC. This finding of epigenomic dysregulation of molecular pathways that have been previously linked to cancer adds biological plausibility to our results.

Testing of newly diagnosed advanced high grade ovarian cancer (OC) patients with the Myriad Genetics MyChoice CDx Plus next generation sequencing-based in vitro diagnostic test emphasizes the need for public insurance coverage of genetic testing: Results of a national program by the Hellenic Society of Medical Oncology (HeSMO).

e18520 Background: Homologous Recombination deficiency (HRD) represents a distinct entity in OC. Clinical data suggest that treatment selection can be based on both BRCA1/2 mutations and bearing Genomic Instability Status (GIS). Testing for GIS is critical in order to expand patients’ pool for targeted treatment. Myriad my Choice, is currently the only FDA approved test that can detect HRD by assessing BRCA1/BRCA2 mutation and GIS status in OC tumor specimens using 3 biomarkers: loss of heterozygosity, telomeric allelic imbalance and large-scale state transitions. To address this need, HeSMO has initiated a national program to provide access to myChoice to newly diagnosed patients with high grade stage III/IV OC. Methods: Patients with newly diagnosed stage III/IV high grade OC were eligible to participate in this program. The specific performance characteristics of myChoice CDx assay were determined on FFPE tumor samples by the evaluation of a range of representative tumor BRCA1 and BRCA2 sequence variants (e.g. single nucleotide variants, insertions or deletions and variants in homopolymers), Large Rearrangements (e.g. deletions and duplications affecting single and multiple exons) and a representative range of GIS. The overall results are composed of two major components: GIS Status (positive or negative) and tumor (t) BRCA1/2 Status (positive or negative). The combined results form the basis of the overall interpretation of the myChoice CDx Myriad HRD Status. Results: From December 2020 to January 2022, 454 patients from all over the country were tested within this program. 220 patients (48.46%) had a positive GIS report and 179 (39.43%) had a negative one. Among GIS positive cases, 122 patients were tBRCAwt (26.87%) 78 patients were tBRCA mutated (17.18%) and 10 patients had suspected deleterious BRCA1/2 mutations (2.20%). Inconclusive was the report in 38 specimens (8.37%) and myChoice Lab failed to complete the analysis in 15 cases (3.30%). Furthermore, mutations were also detected in a number of other genes, including but not limited to, ATM, BRIP1, PALB2, RAD51C, RAD51D, FANCL, CHEK2. Conclusions: In our series, 48.46% of the patients with high grade OC tested as BRCA1/2 and/or GIS positive, in accordance with published data, underlying the clinical need to implement GIS testing in OC patients’ molecular evaluation. Apart from the significant implications for treatment possibilities in an expanded patients’ population, these results are important for cancer prevention. We strongly believe that our results will strengthen our efforts for reimbursement of such testing in high grade OC patients, and will serve as a roadmap for the establishment of local HRD testing solutions.

Predictors of long-term survivorship after neoadjuvant chemotherapy in advanced ovarian cancer patients

Objectives: Although non-inferior overall survival and reduced surgical morbidity with neoadjuvant therapy (NAC) compared to primary debulking surgery, upfront debulking surgery remains the treatment of choice for newly diagnosed advanced stage ovarian cancer (OC) in the US. This can be partially attributed to the association of aggressive surgical treatment with long term survival (LTS) demonstrated in high grade serous OC (HGSOC). On the contrary, NAC has been shown to lower the odds for LTS. We aimed to identify clinico-pathologic factors associated with LTS in advanced epithelial OC (EOC) treated with NAC. Methods: This is a retrospective case-control study. Women with FIGO stage III-IV high grade epithelial cancer of the ovary, fallopian tube or peritoneum diagnosed and treated with NAC prior to 2013 were extracted from consecutive patient records of the Tel-Aviv Sourasky Medical Center. Women surviving longer than 7 years from diagnosis (defined as long-term survivors, LTS) were compared to women surviving 6-24 months from diagnosis (defined as short-term survivors, STS). Patients with low grade or low malignant potential tumors were excluded. Results: We identified 190 women with stage III/IV epithelial OC. Seventy-eight patients (41%) survived longer than 5 years from diagnosis and 47 (24%) survived longer than 7 years from diagnosis, significantly higher proportions compared to previous reports. Thirty-nine patients (20%) survived 6-24 months, similar to previous reports. Clinicopathologic and treatment characteristics of both groups are displayed in Table 1. CA125 pre-treatment or after 4 courses of chemotherapy and the number of adjuvant and total chemotherapy courses administered were similar between the groups. LTS were significantly younger than STS at diagnosis, with a mean age of 60.05 years vs 65.95 years, respectively (p=0.008). The majority of LTS received 3 courses of NAC or less compared to STS (59.6% vs 33.4%), implying a smaller disease burden or better response to NAC. LTS had a significantly longer disease-free interval (80.49 months vs 3.65 months, p Download : Download high-res image (404KB) Download : Download full-size image Conclusions: Our analysis, to the best of our knowledge, is the first to demonstrate that NAC does not compromise the odds of long-term survivorship in women with advanced EOC, further strengthening NAC as an equivalent alternative to primary debulking surgery. In addition, we identified basic clinicpathologic and treatment-related factors associated with long term survival of epithelial OC patients treated with NAC. Further investigation is needed to determine which factors should be integrated into treatment-related decisions.

Mutational profile of hereditary breast and ovarian cancer – Establishing genetic testing guidelines in a developing country

PurposeBecause many countries lack the capacity to follow the international guidelines for genetic testing, we suggest the specific approach for establishing local genetic testing guidelines that could be applied in developing countries. We focus on hereditary breast (BC) and ovarian cancer (OC) in Serbia. MethodsFrom the cohort of 550 persons who were referred for genetic counseling at the Institute for Oncology and Radiology of Serbia, 392 were selected. Personal and family histories were collected and germline DNA was sequenced with NGS in a panel of 20 genes. ResultsPathogenic (PV) and likely-pathogenic variants (LPV) were detected in 8 genes with the frequency of 23.7%. The most frequent were in BRCA1(7.6%), BRCA2(4.8%), PALB2(4.1%) and CHEK2(3.8%). They were also detected in ATM(1.8%), NBN(0.8%), TP53(0.5%) and RAD51C(0.3%). Whereas high carrier probability (CP), bilateral BC, BC and OC in the same patient and family history (FH) of BC/OC, were the strongest predictors for BRCA1/2 PV/LPV, lower CP values and early age of BC onset without FH were associated with higher frequency of PALB2 and CHEK2 PV/LPV. ConclusionsPopulation specific studies to identify specific mutational patterns and predictors of PV/LPV should be conducted in order to make scientifically sound and cost-effective guidelines for genetic testing in developing countries.

ENGOT-ov54/Swiss-GO-2/MATAO including LOGOS (Low-Grade Ovarian cancer Sub-study): MAintenance Therapy with Aromatase inhibitor in epithelial Ovarian cancer—A randomized, double-blinded, placebo-controlled, multicenter phase III Trial.

TPS5598 Background: The prognosis of advanced epithelial ovarian cancer (OC) is poor with a relapse rate of 75% at 5 years. Some 80% of OC express estrogen receptor (ER). This is the first trial that wants to capitalize on this and prospectively evaluates letrozole, a potent aromatase inhibitor, as initial maintenance treatment for high and low grade OC. Methods: Eligible pts have primary OC, FIGO Stage II-IV with low or high grade serous or endometrioid histology, with (interval) debulking surgery, ECOG-status 0-2, Positivity (≥ 1%) for ER expression, and at least 4 cycles of platinum-based chemotherapy (neoadjuvant allowed). Pts are allowed to undergo concurrent maintenance treatment with bevacizumab and PARP inhibitors. Extensive quality of life (QoL) questionnaires via an App and physical activity measurements by a tracking device as well as G8 geriatric score, ESGO surgery questionnaire, and Charleson Comorbidity Index are routinely assessed. Primary objective is to evaluate the efficacy of letrozole maintenance therapy after standard surgical and chemotherapy treatment as measured by Progression Free Survival (PFS) compared to no maintenance therapy (placebo). Primary outcome is PFS, defined as time from date of first letrozole/placebo administration until date of progression or death by any cause. Stratification for high and low grade histologies and ER measurement is performed via a digital centralized pathology review process. Final analysis will be performed for the whole cohort and for the subgroup of low grade ovarian cancers (LOGOS subprotocol). Secondary objectives and outcomes are overall survival (OS), quality adjusted progression free survival (QAPFS), time to first subsequent treatment (TFST), quality adjusted time without symptoms (TWiST), and health related QoL. Study is designed as international, randomized (1:1 ratio), two-arm, multi-centric, double-blinded, placebo-controlled superiority phase III trial. In total, 528 pts will be randomly assigned to letrozole or placebo for 5 yrs or until unacceptable toxicity, progression of underlying disease, or study discontinuation. Final analysis is planned after 5 years without interval analysis and follow-up is collected for up to 10yr and for the low-grade cohort for up to 12yr. Clinical trial information: NCT04111978.

Adenylate kinase 7 is a prognostic indicator of overall survival in ovarian cancer.

Ovarian cancer (OC), a common malignant heterogeneous gynecological tumor, is the primary cause of cancer-related death in women worldwide. Adenylate kinase (AK) 7 belongs to the adenylate kinase (AK) family and is a cytosolic isoform of AK. Recent studies have demonstrated that AK7 is expressed in several human diseases, including cancer. However, there is a scarcity of reports on the relationship between AK7 and OC. Here, we compared the expression of AK7 in normal and cancerous ovarian tissues from The Cancer Genome Atlas database and used the c2 test to assess the correlation between AK7 levels and the clinical symptoms of OC. Finally, the prognostic significance of AK7 in OC was determined using the Kaplan–Meier analyses and Cox regression and performed gene set enrichment analysis to detect any relevant signaling pathways. We found that AK7 levels were substantially downregulated in OC than that in normal ovarian tissues (P < .001). Low AK7 levels were related to the patients’ age (P = .0093) in OC. The median overall survival (OS) of patients with low AK7-expressing OC was shorter than patients with high AK7-expressing OC (P = .019). The Cox regression analysis (multivariate) identified low AK7 levels were independently related to the prognosis of OC (HR 1.34; P = .048). Our study demonstrated that the downregulated levels of AK7 could serve as an independent prognostic indicator for the OS in OC. Additionally, gene set enrichment analysis revealed that EMT, apical junction, TGF-b signaling, UV response, and myogenesis were associated in the low AK7 expression phenotype (NOM P < .05).

Diagnostic Value of Plasma Annexin A2 in Early-Stage High-Grade Serous Ovarian Cancer.

Ovarian cancer (OC) is commonly diagnosed at advanced stage when prognosis is poor. Consequently, there is an urgent clinical need to identify novel biomarkers for early detection to improve survival. We examined the diagnostic value of the calcium phospholipid binding protein annexin A2 (ANXA2), which plays an important role in OC metastasis. Annexin A2 plasma levels in patients with high grade serous OC (n = 105), benign ovarian lesions (n = 55) and healthy controls (n = 143) were measured by ELISA. Annexin A2 levels were found to be significantly increased in patients with stage I (p < 0.0001) and stage IA (p = 0.0027) OC when compared to healthy controls. In the logistic regression models followed by receiver operating characteristics (ROC) curve analyses, plasma annexin A2 showed 46.7% sensitivity at 99.6% specificity in distinguishing stage IA OC patients from healthy controls and 75% sensitivity at 65.5% specificity in the diagnosis of stage IA versus benign ovarian tumors. In the diagnosis of stage IA OC versus normal controls, the combination of plasma annexin A2 and CA125 showed 80% sensitivity at 99.6% specificity (AUC = 0.970) which was significantly higher than for CA125 (53.3% sensitivity at 99.6% specificity; AUC = 0.891) alone. The diagnostic accuracy in distinguishing stage IA OC from benign ovarian disease when combining annexin A2 and CA125 (71.4% accuracy at 100% sensitivity) was almost twice as high compared to CA125 (37.1% accuracy at 100% sensitivity) alone. In conclusion, annexin A2 in combination with CA125 has potential as a biomarker for the early detection of OC and to predict malignancy in patients with ovarian lesions, warranting further investigations.

A Comprehensive Molecular and Clinical Analysis of the piRNA Pathway Genes in Ovarian Cancer.

Simple SummaryAlthough ovarian cancer (OC) is one of the most lethal gynecological cancers, its development and progression remain poorly understood. The piRNA pathway is important for transposon defense and genome stability. piRNA maturation and function involve a number of genes known as the piRNA pathway genes. These genes have recently been implicated in cancer development and progression but information about their role in OC is limited. Our work aimed to provide a better understanding of the roles of piRNA pathway genes in OC. Through analyzing changes in the abundance of 10 piRNA pathway genes, we discovered gene expression differences in benign vs. cancer, chemosensitive vs. chemoresistant and post hormone treatment in OC samples and cells. Furthermore, we observed the differential effects of these genes on patient survival and OC cell invasion. Overall, this work supports a role of the piRNA pathway genes in OC progression and encourages further study of their clinical relevance.Ovarian cancer (OC) is one of the most lethal gynecological malignancies, yet molecular mechanisms underlying its origin and progression remain poorly understood. With increasing reports of piRNA pathway deregulation in various cancers, we aimed to better understand its role in OC through a comprehensive analysis of key genes: PIWIL1-4, DDX4, HENMT1, MAEL, PLD6, TDRD1,9 and mutants of PIWIL1 (P1∆17) and PIWIL2 (PL2L60). High-throughput qRT-PCR (n = 45) and CSIOVDB (n = 3431) showed differential gene expression when comparing benign ovarian tumors, low grade OC and high grade serous OC (HGSOC). Significant correlation of disparate piRNA pathway gene expression levels with better progression free, post-progression free and overall survival suggests a complex role of this pathway in OC. We discovered PIWIL3 expression in chemosensitive but not chemoresistant primary HGSOC cells, providing a potential target against chemoresistant disease. As a first, we revealed that follicle stimulating hormone increased PIWIL2 expression in OV-90 cells. PIWIL1, P1∆17, PIWIL2, PL2L60 and MAEL overexpression in vitro and in vivo decreased motility and invasion of OVCAR-3 and OV-90 cells. Interestingly, P1∆17 and PL2L60, induced increased motility and invasion compared to PIWIL1 and PIWIL2. Our results in HGSOC highlight the intricate role piRNA pathway genes play in the development of malignant neoplasms.

NOGGO Ov-42/MAMOC: Rucaparib maintenance after bevacizumab maintenance following carboplatin-based first line-chemotherapy in ovarian cancer patients.

TPS6102 Background: Ovarian cancer (OC) is associated with the highest mortality rates among gynecological malignancies, with most patients being diagnosed in advanced stages. The most common histological subtype is high grade serous OC, which is characterized by deficiency in homologous recombination. Debulking surgery, followed by platinum based chemotherapy and bevacizumab (bev), followed by maintenance therapy with bev, is the standard therapy for advanced BRCA wild type (BRCAwt) OC patients in Germany. BRCA mutant patients will receive maintenance with olaparib, according to SOLO1 data. The anticancer effects of PARP inhibitors (PARPi) seem to be increased by the addition of antiangiogenic drugs. Preclinical data showed increased HRD in tumors pretreated with bev, and clinical trials showed a benefit of the combination of antiangiogenic drugs and PARPi vs. PARPi alone. NOGGO Ov-42/MAMOC trial (NCT04227522) is a phase III, randomized, placebo-controlled study evaluating rucaparib maintenance following bevacizumab maintenance for the treatment of advanced primary high grade BRCAwt OC. Methods: 190 patients with histologically confirmed advanced (FIGO stage IIIA- IV of the 2014 FIGO classification) high grade serous or high grade endometrioid (based on local histopathological findings) OC, fallopian tube cancer, primary peritoneal cancer or clear cell carcinoma of the ovary will be randomized 2:1 to receive either rucaparib 600mg BID or placebo as maintenance therapy following first line chemotherapy with 6 cycles of Carboplatin/Paclitaxel and at least 12 cycles of bev, given together with chemotherapy and as maintenance. Only BRCAwt patients will be included in the trial. Randomization is stratified by surgery planned timepoint (neoadjuvant vs. adjuvant), surgical outcome (no residual tumor mass vs. residual tumor mass), response to chemotherapy followed by bev (CR/NED vs. PR/SD) and study center. Treatment will continue for 24 months or until disease progression, unacceptable toxicity, or withdrawal. Primary endpoint is PFS in BRCAwt patients per RECIST v1.1. Secondary endpoints are PFS2, quality of life (EORTC QLQ-C30/OV28, FSI, SF-12, PROC-CTCAE, every day memory questionnaire), daily activity, time to next medical intervention, time to next subsequent therapy, safety assessments and OS. Clinical trial information: NCT04227522.

Multigene Panel Germline Testing of 1333 Czech Patients with Ovarian Cancer.

Ovarian cancer (OC) is the deadliest gynecologic malignancy with a substantial proportion of hereditary cases and a frequent association with breast cancer (BC). Genetic testing facilitates treatment and preventive strategies reducing OC mortality in mutation carriers. However, the prevalence of germline mutations varies among populations and many rarely mutated OC predisposition genes remain to be identified. We aimed to analyze 219 genes in 1333 Czech OC patients and 2278 population-matched controls using next-generation sequencing. We revealed germline mutations in 18 OC/BC predisposition genes in 32.0% of patients and in 2.5% of controls. Mutations in BRCA1/BRCA2, RAD51C/RAD51D, BARD1, and mismatch repair genes conferred high OC risk (OR > 5). Mutations in BRIP1 and NBN were associated with moderate risk (both OR = 3.5). BRCA1/2 mutations dominated in almost all clinicopathological subgroups including sporadic borderline tumors of ovary (BTO). Analysis of remaining 201 genes revealed somatic mosaics in PPM1D and germline mutations in SHPRH and NAT1 associating with a high/moderate OC risk significantly; however, further studies are warranted to delineate their contribution to OC development in other populations. Our findings demonstrate the high proportion of patients with hereditary OC in Slavic population justifying genetic testing in all patients with OC, including BTO.

Abstract AP27: A PHASE 2 STUDY OF TPIV200/HUFR-1 (A MULTI-EPITOPE FOLATE RECEPTOR ALPHA VACCINE) IN COMBINATION WITH DURVALUMAB IN PATIENTS WITH PLATINUM RESISTANT OVARIAN CANCER

Abstract INTRODUCTION: Therapy with single-agent immune checkpoint inhibitors in ovarian cancer (OC) to date has demonstrated marginal benefit, calling for rational combinations. Vaccination against tumor-associated antigens (TAA's) is a potential strategy to increase therapeutic efficacy by enhancing immunogenicity. Folate receptor alpha (FRα) is overexpressed in the majority of ovarian cancers (OC) and presents a compelling antigenic target for immunotherapy. TPIV200 is a GM-CSF-adjuvanted multi-epitope peptide anti-FRα vaccine targeting the most highly-antigenic moieties of FRα, which in recent phase I studies elicited durable immune response in over 90% of patients with ovarian and breast cancer. The current phase II study sought to examine whether a combination of TPIV200 with PD-L1 inhibitor durvalumab would result in enhanced anti-tumor immunity and therapeutic efficacy in patients with advanced platinum-resistant OC. METHODS: Twenty-seven patients with platinum resistant or refractory OC were enrolled over a 10-month period. Treatment was administered in 28-day cycles. Patients were treated with TPIV200 and GM-CSF on day 1 for 6 cycles and durvalumab on days 1 and 15 at 10mg/kg for 12 cycles. Radiologic assessments were conducted every 12 weeks. Treatment was continued until completion, evidence of clinical or radiologic progression, intolerance, or withdrawal. Exploratory correlative endpoints included tissue microenvironment analyses, including expression of PD-L1 and FRα, and peripheral vaccine-specific immune responses. RESULTS: The study enrolled 27 women with advanced OC. Median age at enrollment was 64 (42-76). Median number of prior lines of therapy was 3 (range 1-8). Of these patients, 85% (23) had high grade serous OC. There were no objective responses seen on the study. PFS rate at 24 weeks was 22%, with median PFS of 12 weeks. Six patients remained on treatment beyond 24 weeks. The majority of patients post-progression went on to receive subsequent standard therapy with durable clinical benefit. At the median follow up of 15.4 months, median OS was not reached. CONCLUSIONS: TPIV200/huFR-1 and durvalumab can be safely combined in heavily-pretreated patients with platinum-resistant OC. A subset of patients exhibited durable disease stabilization. Post-immunotherapy follow up was suggestive of improved clinical benefit from standard therapies, creating a rationale for exploration of these agents in combination with chemotherapy. Citation Format: Dmitriy Zamarin, Oladapo Yeku, Rosin E. O'Cearbhaill, Karen A. Cadoo, Jacqueline Gallagher, Sara Kravetz, Autumn McDonnell, Tiffany Troso-Sandoval, Paul Sabbatini, Stuart Lichtman, William Tew, Vicky Makker, Rachel N. Grisham, David M. Hyman, Carol Aghajanian, Jason Konner. A PHASE 2 STUDY OF TPIV200/HUFR-1 (A MULTI-EPITOPE FOLATE RECEPTOR ALPHA VACCINE) IN COMBINATION WITH DURVALUMAB IN PATIENTS WITH PLATINUM RESISTANT OVARIAN CANCER [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 AP27.

1015P - Advanced ovarian cancer: Is residual disease after debulking surgery affected by genetics factors involved in angiogenesis and immunity pathways?

BackgroundThe residual disease (RD) after debulking surgery is one of the strongest prognostic factors in ovarian cancer (OC) patients. Despite surgical efforts, most patients do not achieve "optimal" cytoreduction (R0) even in high-volume centres. The interplay between cancer-promoted angiogenesis and host immune-system could foster cancer dissemination, reducing the likelihood of surgical eradication. The aim of this study was to assess whether the presence of germline polymorphisms in genes involved in angiogenesis and immunity pathways was predictive of R0. MethodsA cohort of 230 patients with stage III-IV, high grade epithelial OC treated with debulking surgery and platinum-based therapy without bevacizumab, was retrospectively enrolled. A panel of 192 single nucleotide polymorphisms (SNPs) in 34 angiogenesis and immune system-related genes was analyzed with Illumina GoldenGate Genotyping Assay. Log-additive, dominant and recessive genetic models were evaluated using a multivariate logistic regression adjusted for type of surgery (i.e. primary or interval). False discovery rate (FDR) test<0.2 was used for multiple testing data correction. ResultsThirteen SNPs were significantly associated with RD. Among them, MMP3-rs569444, TLR3-rs5743303 and VEGFA-rs2146323 passed the FDR filter. Patients carrying the variant alleles of MMP3-rs569444 (OR=2.52, 95%CI 1.42-4.47, p=0.0326) and VEGFA-rs2146323 (OR=1.83, 95%CI 1.21-2.75, p=0.0375) showed an increased risk of RD. Conversely, TLR3-rs5743303 carriers were more likely to achieve R0 (OR=0.43, 95%CI 0.27-0.7, p=0.0004). ConclusionsAngiogenesis and the immune-system competence are key players in OC growth and could influence the burden of RD. In our cohort, individual polymorphisms on angiogenesis (VEGFA), extracellular matrix degradation (MMP3) and innate immunity activation (TLR3) pathways were independent predictive factors of RD. These markers, whether validated, might underline the role of host genetics factors in predicting R0. Moreover, if VEGFA-rs2146323 variant carriers could benefit the most from bevacizumab appears as an intriguing question. Legal entity responsible for the studyToffoli Giuseppe. FundingHas not received any funding. DisclosureF. Puglisi: Honoraria (self), Advisory / Consultancy: Amgen; Advisory / Consultancy: Celgene; Advisory / Consultancy: Eisai; Advisory / Consultancy: Eli Lilly; Honoraria (self), Advisory / Consultancy: Ipsen; Advisory / Consultancy, Research grant / Funding (self): Novartis; Advisory / Consultancy: Pfizer; Advisory / Consultancy, Research grant / Funding (self): Roche; Honoraria (self): Pierre Fabre; Advisory / Consultancy: Merck Sharp & Dohme; Advisory / Consultancy: Takeda; Research grant / Funding (self): AstraZeneca. All other authors have declared no conflicts of interest.

Abstract 364: The dopamine receptor D2 antagonist ONC201 has anti-tumorigenic activity in obesity-driven epithelial ovarian cancer

Abstract Objectives: ONC201 is an orally bioavailable dopamine receptor D2 antagonist that induces tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), and TRAIL has been implicated in both the physiopathology of ovarian cancer (OC) and obesity. In addition, DRD2 is a G protein-coupled receptor that activates the trimeric G-protein complex Ras, modulating downstream metabolic pathways such as Akt-signaling which is highly dysregulated in both obesity and OC. ONC201 has demonstrated anti-tumorigenic activity in solid tumors, including uterine serous carcinoma, without significant toxicity in phase 1/2 trials. Thus, we sought to evaluate the anti-tumorigenic effects of ONC201 in human ovarian cancer (OC) cell lines and a high grade serous OC mouse model (K18-gT121+/-;p53fl/fl;Brca1fl/fl; KpB), using both obese and lean mice. Methods: The human epithelial OC cell lines (OVCAR3, SKOV3, IGROV, OVCAR433, and OVCAR5) were treated with ONC201 at doses of 0.01 to 250 μM. Cell proliferation and apoptosis were assessed by MTT and Annexin V assays, respectively. Adhesion and invasion were assessed by laminin and wound healing assays, respectively. For our animal study, we utilized the K18-gT121+/-; p53fl/fl;Brca1fl/fl (KpB) high grade serous OC mouse model. KpB mice were fed either a low fat diet (LFD, lean) with 10% calories from fat, or a high fat diet (HFD, obese) with 60% calories from fat in order to mimic diet-induced obesity. Following tumor onset, obese and lean mice were treated with vehicle or ONC201 (130 mg once a week, oral gavage) for 4 weeks (n = 8-10 mice/group). Results: ONC201 significantly decreased cell proliferation in a dose-dependent manner in all five cell lines, with a range of IC50s between 1 and 10μM. Moreover, ONC201 increased Annexin V expression in a dose-dependent manner in both the SKOV3 and OVCAR5 cell lines (p&amp;lt;0.05). Treatment with ONC201 reduced cell adhesion by 25-30% as well as invasion by 20-25% in both OC cell lines when compared to controls (p&amp;lt;0.05). HFD-fed mice (obese) had tumors that were significantly greater in size as compared to LFD-fed mice (lean) (p&amp;lt;0.05). ONC201 decreased tumor weight/size by 65% in the obese mice and 61% in the lean mice (p&amp;lt;0.01). Conclusions: ONC201 inhibited cell growth, induced apoptosis and decreased cellular adhesion and invasion in human OC cells. ONC201 was efficacious in reducing ovarian tumor growth in both obese and non-obese KpB mice. These results suggest that ONC201 holds promise as a novel targeted therapy in the treatment of OC. Citation Format: Allison Staley, Katherine Tucker, Ziwei Fang, Yali Fan, Wenchuan Sun, Yajie Yin, Yingao zhang, Varun Prabhu, Chunxiao Zhou, Victoria Bae-Jump. The dopamine receptor D2 antagonist ONC201 has anti-tumorigenic activity in obesity-driven epithelial ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 364.

A randomized double-blind placebo-controlled phase II trial comparing gemcitabine monotherapy to gemcitabine in combination with adavosertib in women with recurrent, platinum resistant epithelial ovarian cancer: A trial of the Princess Margaret, California, Chicago and Mayo Phase II Consortia.

5518 Background: Platinum resistant ovarian cancer (OC) remains a therapeutic challenge. High grade serous OC (HGSOC) harbors TP53 mutations leading to increased dependency on S- and G2-phase checkpoints. Wee1 inhibition with Adavosertib (AZD 1775) (A) induces G2 checkpoint escape. Gemcitabine (G) is an antimetabolite therapy and blocks the progression of cells through the G1/S phase. We hypothesized that combining G+A would be synergistic and overcome resistance. Methods: We conducted a multicentre double-blind 2:1 randomized phase 2 trial to assess the progression free survival (PFS) in women with recurrent platinum-resistant/refractory HGSOC receiving G+A or G+placebo (P) (NCT02151292). Eligibility required measurable disease and feasibility of paired tumor biopsies; no limitation in prior lines of therapy. Non HGSOC histologic subtypes were enrolled in a separate non-randomized exploratory cohort. A/P was given orally at 175mg QD on D1-2, D8-9 and D15-16 with G 1000mg/m² IV D1, D8 and D15 in a 28-day cycle until progression or unacceptable AE. Tumor staging was scheduled every 8 weeks. TP53 mutations were analyzed on archival tissue with Sanger sequencing, TAm-Seq and IHC. TP53 mutation will be also assessed in circulating tumor DNA (ctDNA). Whole exome and RNA sequencing were performed on paired tumor tissues. Results: 124 patients (pts) with median of 3 prior lines of therapy (range 1-10) from 12 centres across Canada and US were enrolled between Sep 2014 to May 2018, with 99 pts randomized (65 in Arm G+A and 34 in G+P). 5 pts were ineligible; 64 pts have died. The median follow-up was 14.3 months. Main related AE was hematologic toxicity (Anemia G≥3: 31% in G+A vs 18% in G+P; Thrombocytopenia G≥3: 31% vs 6%; Neutropenia G≥3: 62% vs 30%). PFS was significantly improved from 3.0 to 4.6 months (HR 0.56 (95%CI: 0.35-0.90, p=0.015 Log rank). There was a significant improvement in overall survival (OS) from 7.2 to 11.5 months (HR 0.56 (95%CI: 0.34-0.92, P=0.022). Partial response by RECIST 1.1 was observed in 13 (21%) and 1 (3%) pts for Arms G+A and G+P, respectively (p=0.02). From the 25 pts in the exploratory cohort, 3 (12%) partial responses were observed. Final results will be reported at the meeting. Conclusion: Addition of adavosertib to gemcitabine in women with platinum resistant/refractory OC improved response rate, PFS and OS with manageable toxicity. Clinical trial information: NCT02151292.

Quinacrine upregulates p21/p27 independent of p53 through autophagy-mediated downregulation of p62-Skp2 axis in ovarian cancer

We have previously shown that the anti-malarial compound Quinacrine (QC) inhibits ovarian cancer (OC) growth by modulating autophagy. In the present study we extended these studies to identify the molecular pathways regulated by QC to promote apoptosis independent of p53 status in OC. QC exhibited strong anti-cancer properties in OC cell lines in contrast to other anti-malarial autophagy inhibiting drugs. QC treatment selectively upregulated cell cycle inhibitor p21, and downregulated F box protein Skp2 and p62/SQSTM1 expression independent of p53 status. Genetic downregulation of key autophagy protein ATG5 abolished QC-mediated effects on both cell cycle protein p21/Skp2 as well as autophagic cargo protein p62. Furthermore, genetic silencing of p62/SQSTM1 resulted in increased sensitivity to QC-mediated apoptosis, downregulated Skp2 mRNA and increased accumulation of p21 expression. Likewise, genetic knockdown of Skp2 resulted in the upregulation of p21 and p27 and increased sensitivity of OC cells to QC treatment. In contrast, transient overexpression of exogenous p62-HA plasmid rescued the QC-mediated Skp2 downregulation indicating the positive regulation of Skp2 by p62. Collectively, these data indicate that QC-mediated effects on cell cycle proteins p21/Skp2is autophagy-dependent and p53-independent in high grade serious OC cells.

BRIP1 loss-of-function mutations confer high risk for familial ovarian cancer, but not familial breast cancer

BackgroundGermline mutations in the BRIP1 gene have been described as conferring a moderate risk for ovarian cancer (OC), while the role of BRIP1 in breast cancer (BC) pathogenesis remains controversial.MethodsTo assess the role of deleterious BRIP1 germline mutations in BC/OC predisposition, 6341 well-characterized index patients with BC, 706 index patients with OC, and 2189 geographically matched female controls were screened for loss-of-function (LoF) mutations and potentially damaging missense variants. All index patients met the inclusion criteria of the German Consortium for Hereditary Breast and Ovarian Cancer for germline testing and tested negative for pathogenic BRCA1/2 variants.ResultsBRIP1 LoF mutations confer a high OC risk in familial index patients (odds ratio (OR) = 20.97, 95% confidence interval (CI) = 12.02–36.57, P < 0.0001) and in the subgroup of index patients with late-onset OC (OR = 29.91, 95% CI = 14.99–59.66, P < 0.0001). No significant association of BRIP1 LoF mutations with familial BC was observed (OR = 1.81 95% CI = 1.00–3.30, P = 0.0623). In the subgroup of familial BC index patients without a family history of OC there was also no apparent association (OR = 1.42, 95% CI = 0.70–2.90, P = 0.3030). In 1027 familial BC index patients with a family history of OC, the BRIP1 mutation prevalence was significantly higher than that observed in controls (OR = 3.59, 95% CI = 1.43–9.01; P = 0.0168). Based on the negative association between BRIP1 LoF mutations and familial BC in the absence of an OC family history, we conclude that the elevated mutation prevalence in the latter cohort was driven by the occurrence of OC in these families. Compared with controls, predicted damaging rare missense variants were significantly more prevalent in OC (P = 0.0014) but not in BC (P = 0.0693) patients.ConclusionsTo avoid ambiguous results, studies aimed at assessing the impact of candidate predisposition gene mutations on BC risk might differentiate between BC index patients with an OC family history and those without. In familial cases, we suggest that BRIP1 is a high-risk gene for late-onset OC but not a BC predisposition gene, though minor effects cannot be excluded.