Ovarian Cancer Cohort Research Articles

Progression-free survival in patients receiving first-line platinum-based therapy in Argentina: OCEANIA study.

e17593 Background: OCEANIA is a retrospective database study that evaluated treatment patterns and outcomes in a cohort of patients diagnosed with all ovarian cancer (OC) types in private healthcare settings in Brazil and Argentina. The present analysis described up to 5-year real-world (RW) outcomes in an OC cohort of patients who received first-line platinum-based treatment (PBT) in Argentina. Methods: Patients with an OC code diagnosed from 2010 to 2019 who received a PBT alone or in combination with other therapeutic modalities (other antineoplastics, surgery, and/or radiotherapy) were selected from a private healthcare provider’s database (Hospital Italiano de Buenos Aires) in Argentina. Frequency of PBT patients by FIGO (International Federation of Gynecology and Obstetrics) stage was described. Cumulative risk of progression to subsequent treatment or death was calculated for one year up to five years after the end of first PBT from the survival analysis (using Kaplan–Meier analyses). RW progression-free survival (RW-PFS) was defined as the time between the end of first PBT and the beginning of subsequent treatment or death; patients who were lost to follow-up were censored at the end of the study period. Results: From 741 OC patients in the database, 321 (43.3%) were exposed to a PBT. Among this population, 89.4% had information about FIGO staging: 39 (13.6%) were stage 1; 23 (8.0%) stage 2; 195 (67.9%) stage 3; and 30 (10.5%) stage 4. During the follow-up period, 209 events were recorded, including 181 progressions to subsequent treatments and 28 deaths. The unadjusted mean (standard deviation) and median RW-PFS were 16 (22.3) months and 6 months, respectively. The adjusted cumulative risks of progression or death for years 1–5 were 53.8%, 67.6%, 71.2%, 74.4%, and 76.1%, respectively. Conclusions: Almost two thirds (65.1%) of patients with OC exposed to PBT progressed to subsequent treatment or death during follow-up. The greatest risk of progression was observed within the first year after end of PBT, likely because almost 80% of patients were at stages 3 and 4 and the therapeutic options available during the study period were limited. Funding: GSK213815.

Abstract CT162: A phase II basket trial of dual anti-CTLA-4 and anti-PD-1 blockade in rare tumors (DART) SWOG S1609: the clear cell ovarian, endometrial, cervical cancer cohorts

Abstract Background: Dual checkpoint inhibition with anti-PD-1 and anti-CTLA4 checkpoint inhibitors have proven to be efficacious in numerous malignancies. This study presents the first results of ipilimumab and nivolumab in the clear cell gynecologic cancer cohorts of the SWOG S1609 Dual Anti-CTLA-4 & Anti-PD-1 blockade in Rare Tumors (DART) trial. Methods: DART is a prospective, open-label, multicenter/multi-cohort phase 2 clinical trial of ipilimumab (1mg/kg IV every 6wk) plus nivolumab (240mg IV every 2wk). The primary endpoint was objective response rate (ORR) (RECIST v1.1) (confirmed CR and PR); progression-free survival (PFS), overall survival (OS), stable disease (SD) >6 months, and toxicity are secondary endpoints. Results: Evaluable patients were as follows: clear cell ovarian cancer (N=19); clear cell endometrial cancer (N=8); clear cell cervical (N=5) (median ages, 53, 66, and 59 years; cohorts 46, 45, and 42, respectively) In the clear cell ovarian cancer cohort, ORR was 21.1% [CR, 15.8%, n=3; PR, 5.3%, n=1]; clinical benefit rate (CBR) (includes stable disease ≥6 months) was 31.6% (6/19 patients). Among three patients with confirmed CR, two patients showed 100% regression (with ongoing response at 36+ months and 37+ months respectively), and the other patient showed 67% regression (due to lymph node < 1.0cm), but eventually progressed after 722 days. One confirmed PR patient achieved 75% regression (ongoing response at 53+ months). Of note, three patients achieved unconfirmed PR; one showed 34% regression (5 months); another, 38% (51.5+ months); and another, 58% regression (5 months). The ORR when including unconfirmed PR is 36.8% (7/19). Median PFS was 3.7 months (95% confidence interval (CI); 1.7-∞). Median OS was 21.7 months (6.4-∞). In the clear cell endometrial cancer cohort, ORR was 0%; CBR, 25% (2/8 patients). Of note, one patient achieved unconfirmed PR with 69% regression (4 months). The ORR when including unconfirmed PR is 12.5% (1/8). Median PFS was 2.0 months (95% confidence interval; 1.8-na). Median OS was 4.3 months (4.2-na). In the clear cell cervical cancer cohort, ORR was 0%; CBR, 20.0% (1/5 patients). Median PFS was 2.2 months (95% CI; 1.9-na). Median OS was 23.6 months (95% CI; 15.3-na). The most common adverse events, in the three cohorts combined, were nausea (37.5%, n=12), fatigue (34.4%, n=11), anorexia (31.2%, n=10), hypothyroidism (31.2%, n=10), and pruritus (28.1%, n=9). Grade 3-4 adverse events were reported in 17 cases (53.1%) with no grade 5 adverse events. Conclusion: Ipilimumab plus nivolumab in 19 clear cell ovarian cancer patients resulted in an ORR of 21.1% and CBR of 31.6%, with two durable CRs ongoing at 3+ years; CBR was 25% and 20%, respectively, in clear cell endometrial and cervical cohorts, with no objective responses, albeit with only 8 and 5 patients per cohort. Correlative studies to determine response/resistance markers are ongoing. Further prospective studies in rare gynecologic malignancies are warranted. Citation Format: Young Kwang Chae, Christopher W. Ryan, Naing Aung, William R. Robinson, Megan Othus, Elad Sharon, David M. O'Malley, Floortje J. Backes, Charles D. Blanke, Ramez N. Eskander, Razelle Kurzrock. A phase II basket trial of dual anti-CTLA-4 and anti-PD-1 blockade in rare tumors (DART) SWOG S1609: the clear cell ovarian, endometrial, cervical cancer cohorts [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT162.

Multi-omics analysis of the Indian ovarian cancer cohort revealed histotype-specific mutation and gene expression patterns.

Introduction: In India, OVCa is women's third most common and lethal cancer type, accounting for 6.7% of observed cancer incidences. The contribution of somatic mutations, aberrant expression of gene and splice forms in determining the cell fate, gene networks, tumour-specific variants, and the role of immune fraction infiltration have been proven essential in understanding tumorigenesis. However, their interplay in OVCa in a histotype-specific manner remains unclear in the Indian context. In the present study, we aimed to unravel the Indian population histotype-specific exome variants, differentially expressed gene modules, splice events and immune profiles of OVCa samples. Methods: We analysed 10 tumour samples across 4 ovarian cancer histotypes along with 2 normal patient samples. This included BCFtool utilities and CNVkit for exome, WGCNA and DESeq2 for obtaining differential module hub genes and dysregulated miRNA targets, CIBERSORTx for individual immune profiles and rMATS for tumour specific splice variants. Result: We identified population-specific novel mutations in Cancer Gene Census Tier1 and Tier2 genes. MUC16, MUC4, CIITA, and NCOR2 were among the most mutated genes, along with TP53. Transcriptome analysis showed significant overexpression of mutated genes MUC16, MUC4, and CIITA, whereas NCOR2 was downregulated. WGCNA revealed histotype-specific gene hubs and networks. Among the significant pathways, alteration in the immune system was one of the pathways, and immune profiling using CIBERSORTx revealed histotype-specific immune cell fraction. miRNA analysis revealed miR-200 family, miR-200a and miR-429 were upregulated in HGSOCs.Splice factor abrasion caused splicing perturbations, with the most abundant alternative splice event being exon skipping and the most spliced gene, SNHG17. Pathway analysis of spliced genes revealed translational elongation and Base excision repair as the pathways altered in OVCa. Conclusion: Integrated exome, transcriptome, and splicing patterns revealed different population-specific molecular signatures of ovarian cancer histotypes in the Indian Cohort.

Analysis of BRCA1 and BRCA2 alternative splicing in predisposition to ovarian cancer

BackgroundThe mRNA splicing is regulated on multiple levels, resulting in the proper distribution of genes' transcripts in each cell and maintaining cell homeostasis. At the same time, the expression of alternative transcripts can change in response to underlying genetic variants, often missed during routine diagnostics. AimThe main aim of this study was to define the frequency of aberrant splicing in BRCA1 and BRCA2 genes in blood RNA extracted from ovarian cancer patients who were previously found negative for the presence of pathogenic alterations in the 25 most commonly analysed ovarian cancer genes, including BRCA1 and BRCA2. Material and methodsFrequency and spectrum of splicing alterations in BRCA1 and BRCA2 genes were analysed in blood RNA from 101 ovarian cancer patients and healthy controls (80 healthy women) using PCR followed by gel electrophoresis and Sanger sequencing. The expression of splicing events was examined using RT-qPCR. ResultsWe did not identify any novel, potentially pathogenic splicing alterations. Nevertheless, we detected six naturally occurring transcripts, named BRCA1ΔE9-10, BRCA1ΔE11, BRCA1ΔE11q, and BRCA2ΔE3, BRCA2ΔE12 and BRCA2ΔE17-18 of which three (BRCA1ΔE11q, BRCA1ΔE11 and BRCA2ΔE3) were significantly higher expressed in the ovarian cancer cohort than in healthy controls (p ≤ 0.0001). ConclusionsThis observation indicates that the upregulation of selected naturally occurring transcripts can be stimulated by non-genetic mechanisms and be a potential systemic response to disease progression and/or treatment. However, this hypothesis requires further examination.

Discovery and ranking of the most robust prognostic biomarkers in serous ovarian cancer

Progress in ovarian cancer treatment lags behind other tumor types. With diagnosis usually at an advanced stage, there is a high demand for reliable prognostic biomarkers capable of the selection of effective chemo- and targeted therapies. Our goal was to establish a large-scale transcriptomic database and use it to uncover and rank survival-associated genes. Ovarian cancer cohorts with transcriptome-level gene expression data and clinical follow-up were identified from public repositories. All samples were normalized and entered into an integrated database. Cox univariate survival analysis was performed for all genes and was followed by multivariate analysis for selected genes involving clinical and pathological variables. False discovery rate was computed for multiple hypothesis testing and a 1% cutoff was used to determine statistical significance. The complete integrated database comprises 1816 samples from 17 datasets. Altogether, 2468 genes were correlated to progression-free survival (PFS), and 704 genes were correlated with overall survival (OS). The most significant genes were WBP1L, ASAP3, CNNM2, and NCAPH2 for progression-free survival and CSE1L, NUAK1, ALPK2, and SHKBP1 for overall survival. Genes significant for PFS were also preferentially significant for predicting OS as well. All data including HR and p values as well as the used cutoff values for all genes for both PFS and OS are provided to enable the ranking of future biomarker candidates across all genes. Our results help to prioritize genes and to neglect those which are most likely to fail in studies aiming to establish new clinically useful biomarkers and therapeutic targets in serous ovarian cancer.

Safety and anti-tumor activity of lisavanbulin administered as 48-hour infusion in patients with ovarian cancer or recurrent glioblastoma: a phase 2a study

Purpose. Lisavanbulin (BAL101553) is the prodrug of avanbulin (BAL27862), a microtubule-destabilizing agent. The goal of this study (NCT02895360) was to characterize the safety, tolerability and antitumor activity of lisavanbulin administered as a 48-hour intravenous (IV) infusion at the recommended Phase 2 dose (RP2D) of 70 mg/m2. Results from the Phase 1 dose-escalation portion of the study identifying the RP2D have been previously reported. Here, we present the findings from the Phase 2a portion of this study. Methods. This multi-center, open-label study included patients with ovarian, fallopian-tube, or primary peritoneal cancer that was either platinum-resistant or refractory (11 patients), or with first recurrence of glioblastoma (12 patients). Lisavanbulin was administered as a 48-hour IV infusion on Days 1, 8, and 15 of a 28-day cycle. Results. Lisavanbulin was well tolerated in both patient cohorts. Thirteen patients (56.5%) developed 49 adverse events assessed as related to study treatment. The majority were mild or moderate; four were grade 3/4. Sixteen SAEs were reported in nine patients (39.1%), with none considered related to study treatment. No AEs led to permanent treatment discontinuation. Three patients in the ovarian cancer cohort had stable disease with lesion size reductions after two cycles of treatment; in the glioblastoma cohort, one patient showed partial response with a > 90% glioblastoma area reduction as best response, and one patient had stable disease after eight cycles of treatment. Conclusion. This study demonstrated a favorable safety and tolerability profile of 48-hour continuous IV infusion of lisavanbulin in patients with solid extracranial tumors or glioblastoma. Clinicaltrials.gov registration: NCT02895360.

Secondary ovarian cancer after external beam radiotherapy for nonovarian pelvic malignancy.

To examine characteristics and survival of patients who developed secondary ovarian cancer after external beam radiotherapy (EBRT) for a prior nonovarian pelvic malignancy. This is a population-based retrospective cohort study, querying the Surveillance, Epidemiology, and End Result program from 1975 to 2016. 167,269 women who received EBRT for 7 malignancies (anus, rectum, bladder, cervix, uterus, vulva, or vagina) were examined to identify subsequent secondary ovarian cancer diagnosis after EBRT. Then, within the ovarian cancer cohort (n=147,618), characteristics and survival of patients with secondary ovarian cancer after EBRT were compared to those with ovarian cancer who did not receive prior EBRT. Following EBRT for a pelvic malignancy, 215 (1.3 per 1000) patients developed secondary ovarian cancer. Among those, the most frequent prior malignancy was cervical cancer (45.6%), followed by rectal cancer (20.9%). The median time from prior EBRT to secondary ovarian cancer was 8.8 years (interquartile range, 2.8-14.5). In multivariable analysis, patients with secondary ovarian cancer after EBRT were more likely to be older, and have a recent year of diagnosis, but less likely to have early-disease compared to ovarian cancer patients without prior EBRT (all, P<0.05). In weighted model, patients with secondary ovarian cancer after EBRT had decreased overall survival compared to those with ovarian cancer without prior EBRT (5-year rates, 19.6% versus 39.9%, hazard ratio 1.62, 95% confidence interval 1.43-1.85). Similar association was observed in ages <70, ≥70, White, non-White, early-disease, and advanced-disease in sensitivity analyses. Radiotherapy-related secondary ovarian cancer may be associated with decreased overall survival.

Diagnostic and prognostic potential of the microbiome in ovarian cancer treatment response

Ovarian cancer (OC) is the second most common gynecological malignancy and the fifth leading cause of death due to cancer in women in the United States mainly due to the late-stage diagnosis of this cancer. It is, therefore, critical to identify potential indicators to aid in early detection and diagnosis of this disease. We investigated the microbiome associated with OC and its potential role in detection, progression as well as prognosis of the disease. We identified a distinct OC microbiome with general enrichment of several microbial taxa, including Dialister, Corynebacterium, Prevotella, and Peptoniphilus in the OC cohort in all body sites excluding stool and omentum which were not sampled from the benign cohort. These taxa were, however, depleted in the advanced-stage and high-grade OC patients compared to early-stage and low-grade OC patients suggestive of decrease accumulation in advanced disease and could serve as potential indicators for early detection of OC. Similarly, we also observed the accumulation of these mainly pathogenic taxa in OC patients with adverse treatment outcomes compared to those without events and could also serve as potential indicators for predicting patients’ responses to treatment. These findings provide important insights into the potential use of the microbiome as indicators in (1) early detection of and screening for OC and (2) predicting patients’ response to treatment. Given the limited number of patients enrolled in the study, these results would need to be further investigated and confirmed in a larger study.

Abstract C091: Deprivation/segregation indices and survival in the AACES ovarian cancer cohort: A mediation analysis

Abstract Deprivation indices (DIs), constructed from area-level socio-economic indicators, attempt to allow for the acknowledged relationship between socio-economic status and health outcomes. Segregation indices (SIs) address the area-level divisions in ethnicity and socio-economic status. In this study we evaluated the effects of deprivation and segregation on ovarian cancer survival among African-American women in a Bayesian hierarchical joint mediation framework. Deprivation and segregation effects considered were the most commonly used: 4 dimensions of Kolak social determinants of health, Yost index, Singh index, the percentage of people below the poverty line, ICE income and race segregation measures, and the concentrated disadvantage index. We analyzed a cohort (n=559) of African-American ovarian cancer patients from the states of Alabama, Georgia, Illinois, Louisiana, New Jersey, North Carolina, Ohio, South Carolina, Tennessee, and Texas and the metropolitan area of Detroit, as part of the African American Cancer Epidemiology Study (AACES). We evaluated the effects of mediation via stage at diagnosis, histology and delayed diagnosis and examined confounding variables: age, current BMI, income, smoking status, and physical activity level, using Bayesian Gibbs variable selection to select the confounders for the final models. Our main result, with the stage as the mediator, showed that increased urbanization, mobility, socio economic status of Kolak dimensions and decreased deprivation measured by Yost index have positive effects on overall survival. 1 unit decrease of deprivation measured by Yost index will lead to 26% decrease of the hazard for ovarian cancer (CI: 0.56,0.91). Similarly, increased urbanization gives positive effect for the overall survival. 1 unit increase of urbanization lead to 27% decrease of hazard (CI: 0.57,0.95). Similar results are found for histology and diagnosis delay: when histology is the mediator, increase of urbanization and socio-economic status, and decreased deprivation measured by Singh, Yost and concentrated disadvantage indices have positive association with overall survival. When delayed diagnosis was our mediator, increased urbanization, socio-economic status and mobility, and decreased deprivation measured by Yost, ICE income and concentrated disadvantage indices have the positive association with overall survival. The results of mediation analyses revealed that Kolak dimensions and decreased deprivation was associated with increased survival from ovarian cancer . In summary, these results indicate that several measures of area-level deprivation, when mediated by intermediate pathway variables, are associated with survival among African-American women diagnosed with ovarian cancer. Their particular direction and level of impact varies with DI or SI chosen. Citation Format: Joanne Kim, Andrew B. Lawson, Joellen Schildkraut, Edward S. Peters, Courtney E. Johnson. Deprivation/segregation indices and survival in the AACES ovarian cancer cohort: A mediation analysis [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr C091.

High expression of SPINT2 promotes immune infiltration and tumor progression in ovarian cancer

This study aimed to identify the function and mechanism of Serine Peptidase Inhibitor, Kunitz Type 2 (SPINT2) in ovarian cancer (OC). The expression of SPINT2 was analyzed using the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) database. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to identify enriched functional categories of SPINT2 and its correlated genes. Correlation of SPINT2 with OC immune infiltration level was analyzed using the Tumor IMmune Estimation Resource (TIMER) web server. The effect of SPINT2 on cell proliferation was detected using cell counting kit-8 (CCK-8) and colony formation assay. Its effects on cell migration and invasion were examined using the transwell assay. Function of SPINT2 in M2 macrophage recruitment was detected using the migration assay. The role of SPINT2 on M2 macrophage differentiation was evaluated using M2 macrophage markers and by detection of interleukin 10 (IL-10) release. An OC cohort study (GSE12470) showed that SPINT2 was highly expressed in OC. The high SPINT2 expression was related to shorter overall survival (OS) and poor recurrence-free survival (RFS). GO and KEGG analysis indicated that SPINT2 associated genes played roles in glycoprotein catabolism, cell adhesion and T cell differentiation. SPINT2 also played a key role in infiltration of macrophages in OC. shSPINT2 reduced viability and colony formation ability of ovarian cancer cell line SK-OV-3 cells. Moreover, shSPINT2 also inhibited the cell migration and invasion. Co-culture of shSPINT2 transfected SK-OV-3 cells with macrophages inhibited the migration of M2 macrophages, and inhibited macrophages polarization from M0 to M2. These results suggested that SPINT2 is involved in infiltration of tumor-associated macrophages (TAMs). SPINT2 also plays an important role in the polarization and migration of macrophages. These findings suggested that SPINT2 has the potential to be explored as a biomarker for OC and a potential target.

Ovarian Cancer-Cell Pericellular Hyaluronan Deposition Negatively Impacts Prognosis of Ovarian Cancer Patients.

Hyaluronan (HA), a component of the extracellular matrix, is frequently increased under pathological conditions including cancer. Not only stroma cells but also cancer cells themselves synthesize HA, and the interaction of HA with its cognate receptors promotes malignant progression and metastasis. In the present study, HA deposition in tissue sections was analyzed by hyaluronan-binding protein (HABP) ligand histochemistry in 17 borderline tumors and 102 primary and 20 recurrent ovarian cancer samples. The intensity and, particularly, localization of the HA deposition were recorded: for the localization, the pericellular deposition around the ovarian cancer cells was distinguished from the deposition within the stromal compartment. These histochemical data were correlated with clinical and pathological parameters. Additionally, within a reduced subgroup of ovarian cancer samples (n = 70), the RNA levels of several HA-associated genes were correlated with the HA localization and intensity. Both stroma-localized and pericellular tumor-cell-associated HA deposition were observed. Cancer-cell pericellular HA deposition, irrespective of its staining intensity, was significantly associated with malignancy, and in the primary ovarian cancer cohort, it represents an independent unfavorable prognostic marker for overall survival. Furthermore, a significant association between high CD44, HAS2 and HAS3 mRNA levels and a cancer-cell pericellular HA-deposition pattern was noted. In contrast, stromal hyaluronan deposition had no impact on ovarian cancer prognosis. In conclusion, the site of HA deposition is of prognostic value, but the amount deposited is not. The significant association of only peritumoral cancer-cell HA deposition with high CD44 mRNA expression levels suggests a pivotal role of the CD44-HA signaling axis for malignant progression in ovarian cancer.

Identification of Tumor Microenvironment Scoring Scheme Based on Bioinformatics Analysis of Immune Cell Infiltration Pattern of Ovarian Cancer.

Background Tumor microenvironment (TME) is the crucial mediator of tumor progression, and the TME model based on immune cell infiltration to characterize ovarian cancer is considered to be a promising strategy. Methods Sample data of three ovarian cancer cohorts were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. The scores of 22 kinds of immune cells were calculated based on CIBERSORT, and the TME clusters (TMECs) of ovarian cancer was determined by ConsensusClusterPlus. Genomic subtype was identified by non-negative matrix factorization (NMF). A TME scoring scheme was constructed using k-means algorithm and principal component analysis (PCA) to quantify the TME infiltration pattern of individuals. Results Four TME subtypes of ovarian cancer samples were defined: TMEC1, TMEC2, TMEC3, and TMEC4. There were also significant differences in overall survival (OS) among the four TMEC, and the OS of TMEC3 was the longest. The difference analysis of TMEC3 and the other three TMECs respectively identified the DEGs and took the intersection, and 585 DEGs were obtained. Two genomic subtypes were identified by NMF based on the expression of 585 genes, which were called GeneC1 and GeneC2. The TME scoring scheme constructed by k-means and PCA algorithm was used to calculate the TME score of ovarian cancer in TCGA. High-TME score was significantly correlated with shorter survival time, older age, lower immunoactivated molecules, and immune checkpoint gene expression. Conclusions This study highlighted the complexity and diversity of TME infiltration patterns in ovarian cancer and constructed a set of TME scoring scheme to reveal TME infiltration patterns and provided new insights into the landscape of TME.

Pan-cancer analyses and molecular subtypes based on the cancer-associated fibroblast landscape and tumor microenvironment infiltration characterization reveal clinical outcome and immunotherapy response in epithelial ovarian cancer.

BackgroundCancer-associated fibroblasts (CAFs) are essential components of the tumor microenvironment (TME). These cells play a supportive role throughout cancer progression. Their ability to modulate the immune system has also been noted. However, there has been limited investigation of CAFs in the TME of epithelial ovarian cancer (EOC).MethodsWe comprehensively evaluated the CAF landscape and its association with gene alterations, clinical features, prognostic value, and immune cell infiltration at the pan-cancer level using multi-omic data from The Cancer Genome Atlas (TCGA). The CAF contents were characterized by CAF scores based on the expression levels of seven CAF markers using the R package “GSVA.” Next, we identified the molecular subtypes defined by CAF markers and constructed a CAF riskscore system using principal component analysis in the EOC cohort. The correlation between CAF riskscore and TME cell infiltration was investigated. The ability of the CAF riskscore to predict prognosis and immunotherapy response was also examined.ResultsCAF components were involved in multiple immune-related processes, including transforming growth factor (TGF)-β signaling, IL2-STAT signaling, inflammatory responses, and Interleukin (IL) 2-signal transducer and activator of transcription (STAT) signaling. Considering the positive correlation between CAF scores and macrophages, neutrophils, and mast cells, CAFs may exert immunosuppressive effects in both pan-cancer and ovarian cancer cohorts, which may explain accelerated tumor progression and poor outcomes. Notably, two distinct CAF molecular subtypes were defined in the EOC cohort. Low CAF riskscores were characterized by favorable overall survival (OS) and higher efficacy of immunotherapy. Furthermore, 24 key genes were identified in CAF subtypes. These genes were significantly upregulated in EOC and showed a strong correlation with CAF markers.ConclusionsIdentifying CAF subtypes provides insights into EOC heterogeneity. The CAF riskscore system can predict prognosis and select patients who may benefit from immunotherapy. The mechanism of interactions between key genes, CAF markers, and associated cancer-promoting effects needs to be further elucidated.

Is APOBEC3A/B deletion polymorphism associated with the risk of ovarian cancer in Norwegian population? A case-control study (237)

Objectives: APOBEC3 subfamily proteins protect human cells from viral infection by introducing mutations to single-stranded DNA and edit genomic DNA by creating double-stranded DNA breaks. APOBEC3 activity is associated with two single-base substitution signatures (SBS), 2 and 13, out of 44 SBS cancer mutation signatures. A germline 30Kb deletion affecting APOBEC3A and APOBEC3B eliminates the coding region of the APOBEC3B gene and creates the APOBEC3A/B fusion transcript. The deletion has been associated with the risk of different cancer types. This study aimed to assess the risk association between the APOBEC3A/B deletion variant and ovarian cancer. Methods: To assess the APOBEC3A/B polymorphism status, DNA extracted from the blood samples of ovarian cancer patients (n=1,398), and healthy female controls (n=1,918) were genotyped using quantitative PCR high-resolution melting (qPCR-HRM) curves. Only participants without detected BRCA1/2 mutations were included for the present analysis. Results were technically validated by genotyping of 21% of the sample set for SNP (rs12628403), an SNP found to be in strong linkage disequilibrium with the deletion allele. Validation of findings from the present study was performed using mining the SNP rs12628403 from Genome-Wide Association Study of Ovarian Cancer Association Consortium (OCAC) derived from >18,000 cases and >26,000 controls. Results: Both ovarian cancer and control cohorts were in Hardy-Weinberg equilibrium for APOBEC3A/B deletion allele distribution (p=0.386 and p>0.4, with a MAF of 0.072 and 0.094, respectively). The deletion allele was associated with reduced risk for ovarian cancer, applying a dominant, allele or recessive models (OR: 0.75, 95% CI: 0.61-0.91, p=0.003; OR: 0.74, 95% CI: 0.62-0.89, p=0.001, and OR: 0.36, 95% CI: 0.10-0.99, p=0.034, respectively). Stratifying patients by age groups, a significantly reduced risk was found among individuals aged 50-59 and 60-69 years. The same association was seen applying dominant and allele models in subgroup analysis by histology; deletion was associated with a reduced risk in serous and non-serous ovarian cancers. The validation analysis with OCAC revealed a trend towards reduced cancer risk, although not reaching statistical significance. Conclusions: APOBEC3A/B deletion variant shows a risk-reducing effect for ovarian cancer in the study population. This pattern maintains in serous and non-serous ovarian cancer subgroups. Objectives: APOBEC3 subfamily proteins protect human cells from viral infection by introducing mutations to single-stranded DNA and edit genomic DNA by creating double-stranded DNA breaks. APOBEC3 activity is associated with two single-base substitution signatures (SBS), 2 and 13, out of 44 SBS cancer mutation signatures. A germline 30Kb deletion affecting APOBEC3A and APOBEC3B eliminates the coding region of the APOBEC3B gene and creates the APOBEC3A/B fusion transcript. The deletion has been associated with the risk of different cancer types. This study aimed to assess the risk association between the APOBEC3A/B deletion variant and ovarian cancer. Methods: To assess the APOBEC3A/B polymorphism status, DNA extracted from the blood samples of ovarian cancer patients (n=1,398), and healthy female controls (n=1,918) were genotyped using quantitative PCR high-resolution melting (qPCR-HRM) curves. Only participants without detected BRCA1/2 mutations were included for the present analysis. Results were technically validated by genotyping of 21% of the sample set for SNP (rs12628403), an SNP found to be in strong linkage disequilibrium with the deletion allele. Validation of findings from the present study was performed using mining the SNP rs12628403 from Genome-Wide Association Study of Ovarian Cancer Association Consortium (OCAC) derived from >18,000 cases and >26,000 controls. Results: Both ovarian cancer and control cohorts were in Hardy-Weinberg equilibrium for APOBEC3A/B deletion allele distribution (p=0.386 and p>0.4, with a MAF of 0.072 and 0.094, respectively). The deletion allele was associated with reduced risk for ovarian cancer, applying a dominant, allele or recessive models (OR: 0.75, 95% CI: 0.61-0.91, p=0.003; OR: 0.74, 95% CI: 0.62-0.89, p=0.001, and OR: 0.36, 95% CI: 0.10-0.99, p=0.034, respectively). Stratifying patients by age groups, a significantly reduced risk was found among individuals aged 50-59 and 60-69 years. The same association was seen applying dominant and allele models in subgroup analysis by histology; deletion was associated with a reduced risk in serous and non-serous ovarian cancers. The validation analysis with OCAC revealed a trend towards reduced cancer risk, although not reaching statistical significance. Conclusions: APOBEC3A/B deletion variant shows a risk-reducing effect for ovarian cancer in the study population. This pattern maintains in serous and non-serous ovarian cancer subgroups.

Modification of the Association Between Frequent Aspirin Use and Ovarian Cancer Risk: A Meta-Analysis Using Individual-Level Data From Two Ovarian Cancer Consortia.

Frequent aspirin use has been associated with reduced ovarian cancer risk, but no study has comprehensively assessed for effect modification. We leveraged harmonized, individual-level data from 17 studies to examine the association between frequent aspirin use and ovarian cancer risk, overall and across subgroups of women with other ovarian cancer risk factors. Nine cohort studies from the Ovarian Cancer Cohort Consortium (n = 2,600 cases) and eight case-control studies from the Ovarian Cancer Association Consortium (n = 5,726 cases) were included. We used Cox regression and logistic regression to assess study-specific associations between frequent aspirin use (≥ 6 days/week) and ovarian cancer risk and combined study-specific estimates using random-effects meta-analysis. We conducted analyses within subgroups defined by individual ovarian cancer risk factors (endometriosis, obesity, family history of breast/ovarian cancer, nulliparity, oral contraceptive use, and tubal ligation) and by number of risk factors (0, 1, and ≥ 2). Overall, frequent aspirin use was associated with a 13% reduction in ovarian cancer risk (95% CI, 6 to 20), with no significant heterogeneity by study design (P = .48) or histotype (P = .60). Although no association was observed among women with endometriosis, consistent risk reductions were observed among all other subgroups defined by ovarian cancer risk factors (relative risks ranging from 0.79 to 0.93, all P-heterogeneity > .05), including women with ≥ 2 risk factors (relative risk, 0.81; 95% CI, 0.73 to 0.90). This study, the largest to-date on aspirin use and ovarian cancer, provides evidence that frequent aspirin use is associated with lower ovarian cancer risk regardless of the presence of most other ovarian cancer risk factors. Risk reductions were also observed among women with multiple risk factors, providing proof of principle that chemoprevention programs with frequent aspirin use could target higher-risk subgroups.

Survivin, sonic hedgehog, krüppel-like factors, and p53 pathway in serous ovarian cancer: an immunohistochemical study

Survivin was previously associated with tumor stage and grade in ovarian cancer and interfered with the tumor's drug sensitivity. In addition, Survivin expression was found to be regulated by the Sonic hedgehog (Shh) pathway, Krüppel-like factor (KLF) family proteins, and p53 pathway. The main aim of this study was to assess the prognostic values of immunohistochemical expression of Survivin, Klf5, Klf11, Shh, p53, p21, and Mdm2 in a cohort of high-grade ovarian serous cancers. Other aims were comparison between high- and low-grade ovarian serous cancer and between platinum-resistant and the other cases. The last aim was to assess the correlations among the immunohistochemical expression of the studied proteins. Retrospective cohort study to assess immunohistochemical expression of Survivin, Klf5, Klf11, Shh, p53, p21, and Mdm2 in a tissue microarray of primary tumor samples among 73 women affected by high-grade ovarian serous cancer and 9 by low-grade ovarian serous cancer. Klf5 and Shh cytoplasmic staining were associated with short overall survival (HR 6.38, 95% CI2.25-18.01, P<.05 and 2.25, 95% CI1.19-4.23, P<.05, respectively). In addition, cytoplasmic Klf5 staining, high Klf11, and p53 nuclear staining were associated with platinum resistance (P<.05). Cytoplasmic Shh score was significantly correlated to the immunohistochemical expression of Klf5, Klf11, Mdm2, and Survivin. Our data highlight the possible role of Klf5 and Shh as prognostic markers, meanwhile confirming the role of the KLF family proteins and p53 in ovarian cancer drug resistance. Moreover, Shh appeared to play an important role in the intracellular network of ovarian neoplasia.

Abstract 1249: Development of a pan-cancer algorithm to predict homologous recombination deficiency and sensitivity to PARPi therapy

Abstract Background: PARP inhibitors (PARPi) are approved for multiple indications with ongoing trials to explore broader utility. However, identifying the right patients for these therapies across multiple disease types remains a challenge. In ovarian cancer, genomic-scar based measures for homologous recombination deficiency (HRD) are approved diagnostics (genome-wide LOH [gLOH] and genomic instability score [GIS]); however, broader utility has not been established. Methods: A pan-cancer genomic profiling dataset (n = 202,472; Foundation Medicine, Cambridge, MA) was split 70:30 for training and validation of an HRD signature using an XGB machine learning model (mlHRD). A broad set of copy number (Macintyre 2018) and indel features (Alexandrov 2020) were used to identify signatures of HRD. gLOH (Coleman 2017) and GIS (Timms 2014) were calculated using copy number profiles. Biallelic alterations were predicted using a computational zygosity algorithm (Sun, 2018). The nationwide, de-identified Flatiron Health-Foundation Medicine ovarian and prostate clinico-genomic databases (FH-FMI CGDB) were utilized for outcomes analysis. The de-identified data originated from approximately 280 US cancer clinics (~800 sites of care). Time to therapy discontinuation (TTD) was estimated with Kaplan-Meier analysis. Hazard ratios were calculated using unadjusted Cox proportional Hazard models. Results: We developed an algorithm to predict HRD status using indel and copy number features (see methods). Across the pan-cancer dataset, the rate of mlHRD was 6.4% with the highest frequency in fallopian tube (30%), ovarian (30%), peritoneal (23%), breast (16%), and prostate cancers (15%). Sensitivity to detect biallelic BRCA1/2 alterations was high across tumors [ovary (93%), prostate (87%), breast (85%), pancreas (80%)]. Beyond BRCA1/2, mlHRD positivity was associated with biallelic alterations in RAD51D (OR = 24, p&amp;lt;1E-10), PALB2 (OR = 23, p&amp;lt;1E-10), BARD1 (OR = 23, p&amp;lt;1E-10), and RAD51C (OR = 19, p&amp;lt;1E-10). In the FH-FMI CGDB ovarian cancer cohort, 150 patients were treated with PARPi (mlHRD positive = 73; negative = 77); mlHRD positivity was associated with improved TTD (median 8.9 mo v 3.9 mo; HR = 0.49 [0.34-0.71], p &amp;lt; 0.001), with similar predictive power to gLOH &amp;gt;16% (HR = 0.55 [0.38-0.79], p = 0.001) and GIS &amp;gt;42 (HR = 0.59 [0.41-0.86], p = 0.006). For 62 patients with prostate cancer treated with PARPi (mlHRD positive = 27; negative = 35), mlHRD was associated with prolonged TTD on PARPi (median 6.8 mo v 3.4 mo; HR = 0.56 [0.30-1.03], p = 0.064), trending more predictive than gLOH &amp;gt;8.29% (Sokol 2020) and GIS &amp;gt;42 (HR = 0.64 [0.29-1.40] and 0.80 [0.37-1.73], respectively; p&amp;gt;0.05). Conclusion: These findings suggest that HRD is associated with genomic scarring beyond ovarian cancer. Additional retrospective and prospective analyses in clinical datasets are needed to explore the utility of this signature. Citation Format: Emmanuel Antonarakis, Jay Moore, Dexter Jin, Tim Chen, Justin Newberg, Zoe Fleischmann, Karthikeyan Murugesan, Garrett Frampton, David Fabrizio, Russell Madison, Ethan Sokol. Development of a pan-cancer algorithm to predict homologous recombination deficiency and sensitivity to PARPi therapy [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 1249.

Dose optimization for MORAb-202, an antibody-drug conjugate (ADC) highly selective for folate receptor-alpha (FRα), using population pharmacokinetic (PPK) and exposure-response (E-R) efficacy and safety analyses.

3090 Background: MORAb-202 is an ADC consisting of farletuzumab (an antibody that binds to FRα) paired with eribulin mesylate (a microtubule dynamics inhibitor) conjugated via a cathepsin B-cleavable linker. A phase 1 dose-escalation and expansion study in patients with advanced solid tumors evaluated MORAb-202 doses ranging from 0.3 mg/kg to 1.2 mg/kg IV every 3 weeks (Shimizu 2021, CCR). The dose-expansion part included starting doses of 0.9 mg/kg and 1.2 mg/kg in an ovarian cancer (OC) cohort. Objective response rates (ORR) by investigator per RECIST v1.1 and rates of all-grade interstitial lung disease (ILD), an adverse event of interest, were lower at the 0.9 mg/kg dose vs the 1.2 mg/kg dose. To support dose optimization for clinical benefit while reducing the risk of ILD, a MORAb-202 PPK model was developed to characterize the pharmacokinetics and to obtain model-predicted exposure measures. Methods: Exposure was predicted for different dosing scenarios: flat dosing, bodyweight (BW)-based dosing with or without a dose cap, adjusted ideal BW dosing, and body surface area (BSA)-based dosing. E-R analyses for efficacy (ie, ORR) and safety (ie, ILD by expert review) were conducted using logistic-regression analysis. Simulations (N = 1000) were performed using a BW distribution from a previous phase 3 farletuzumab study in OC (Vergote 2016, JCO) to predict the probability of ORR and ILD in patients treated with MORAb-202. Results: MORAb-202 exposures were dose proportional, and the pharmacokinetics were described by a 2-compartment model with zero-order IV infusion and first-order elimination. Patients with higher BW had less-than-proportional increases in clearance (allometric exponent [AE] 0.571) and distribution volume (AE 0.524). MORAb-202 demonstrated a positive exposure (based on area under the curve [AUC]) dependence to ORR and ILD. The probability of achieving a tumor response was higher with higher AUC (odds ratio [OR] for an AUC unit change of 1000 µg•h/mL: 1.73 [95% CI 1.06–3.11]). The probability of an ILD event was higher with higher AUC (OR for an AUC unit change of 1000 µg•h/mL: 3.50 [95% CI 1.89–7.81]). Simulations across BW ranges (34.2–144 kg) indicated that BSA-based dosing (33 mg/m2), compared with BW-based dosing (0.9 mg/kg), yielded similar predicted median (90% prediction interval) rates for ORR (33.7% [19.3–62.2] vs 37.9% [20.6–67.5]) and all-grade ILD (46.8% [18.2–88.2] vs 55.1% [20.7–91.9]). However, BSA-based dosing is predicted to reduce ILD in the highest BW quartile (&gt; 80–144 kg) by approximately 35% compared with BW-based dosing. Conclusions: Based on this assessment, BSA-based dosing is predicted to lower the exposure-dependent ILD risk in patients with higher BW and is being further evaluated in ongoing clinical studies. Clinical trial information: NCT03386942.

A phase Ia/Ib study of CBP-1008, a bispecific ligand drug conjugate, in patients with advanced solid tumors.

3000 Background: Folate receptor α (FRα) and vanilloid subfamily member 6 of transient receptor potential channels (TRPV6) are overexpressed in many solid tumors hence could be promising therapeutic targets. CBP-1008 is a first-in-class bi-specific ligand drug targeting FRα and TRPV6 carrying monomethyl auristatin E (MMAE) as payload. Here we report the first-in-human, multicenter, phase Ia/Ib study designed to explore the safety, pharmacokinetics and efficacy of CBP-1008 in advanced solid tumors. Methods: CBP-1008 was administered by intravenous infusion. Phase Ia study included a dose-escalation period initiated by accelerated titration (0.015, 0.03mg/kg d1,15; q28d) and then switched to 3+3 scheme (0.12, 0.15, 0.17, 0.18mg/kg d1,15; q28d) and a dose expansion period. Phase Ib clinical expansion study included 3 cohorts, platinum-resistant ovarian cancer (OC), metastatic triple negative breast cancer (TNBC) and other solid tumors. The primary objective was to assess the safety and preliminary efficacy. Results: As of January 13, 2022, 106 patients received at least one dose of study drug were enrolled (phase Ia: n = 30; phase Ib: n = 76) and received median 3 prior regimens. Included tumor species were OC (n = 52), TNBC (n = 20), ER+/Her2+ breast cancer (BC) (n = 16), lung cancer (n = 3), pancreatic cancer (n = 2) and others (n = 13). In phase Ia study, DLTs were observed in 3 patients (0.12, 0.15, 0.18mg/kg, n = 1 each), including grade 4 hypophosphatemia, neutropenia, febrile neutropenia, and grade 3 hyperglycemia, alanine aminotransferase (ALT). MTD was not yet reached. Majority of adverse events were mild to moderate. The most common grade 3/4 treatment-emerging adverse events (TEAEs) were neutropenia (37.7%), AST elevation (6.6%), ALT elevation (5.7%), hyperglycemia (2.8%), hypohemoglobinemia (2.8%) and nausea (1.9%). Drug-related death was not observed. A total of 69 patients at dose of 0.15mg/kg or above were evaluable for efficacy assessment. There were 11 patients achieved partial response (PR) (OC n = 8, ER+/Her2+ BC n = 2, TNBC n = 1) and 30 patients achieved stable disease (SD). In 32 advanced platinum-resistant OC patients with FRα and/or TRPV6-positive expression, 6 PR and 16 SD were observed. Moreover, 6/18 PR (33.3%) and 8/18 SD (44.4%) were observed in enriched OC patients who showed high score of FRα/TRPV6 receptor. Conclusions: The preliminary results showed that CBP-1008 has manageable safety profile. Antitumor activity was observed in patients with FRα/TRPV6 receptor expression, especially in platinum-resistant OC cohort with high score of the two receptors. Clinical trial information: NCT04740398.

Discovery of new therapeutic targets in ovarian cancer through identifying significantly non-mutated genes

BackgroundMutated and non-mutated genes interact to drive cancer growth and metastasis. While research has focused on understanding the impact of mutated genes on cancer biology, understanding non-mutated genes that are essential to tumor development could lead to new therapeutic strategies. The recent advent of high-throughput whole genome sequencing being applied to many different samples has made it possible to calculate if genes are significantly non-mutated in a specific cancer patient cohort.MethodsWe carried out random mutagenesis simulations of the human genome approximating the regions sequenced in the publicly available Cancer Growth Atlas Project for ovarian cancer (TCGA-OV). Simulated mutations were compared to the observed mutations in the TCGA-OV cohort and genes with the largest deviations from simulation were identified. Pathway analysis was performed on the non-mutated genes to better understand their biological function. We then compared gene expression, methylation and copy number distributions of non-mutated and mutated genes in cell lines and patient data from the TCGA-OV project. To directly test if non-mutated genes can affect cell proliferation, we carried out proof-of-concept RNAi silencing experiments of a panel of nine selected non-mutated genes in three ovarian cancer cell lines and one primary ovarian epithelial cell line.ResultsWe identified a set of genes that were mutated less than expected (non-mutated genes) and mutated more than expected (mutated genes). Pathway analysis revealed that non-mutated genes interact in cancer associated pathways. We found that non-mutated genes are expressed significantly more than mutated genes while also having lower methylation and higher copy number states indicating that they could be functionally important. RNAi silencing of the panel of non-mutated genes resulted in a greater significant reduction of cell viability in the cancer cell lines than in the non-cancer cell line. Finally, as a test case, silencing ANKLE2, a significantly non-mutated gene, affected the morphology, reduced migration, and increased the chemotherapeutic response of SKOV3 cells.ConclusionWe show that we can identify significantly non-mutated genes in a large ovarian cancer cohort that are well-expressed in patient and cell line data and whose RNAi-induced silencing reduces viability in three ovarian cancer cell lines. Targeting non-mutated genes that are important for tumor growth and metastasis is a promising approach to expand cancer therapeutic options.