scholarly journals Homologous recombination deficiency in epithelial ovarian cancer

2020 ◽  
Vol 13 (4) ◽  
pp. 367-370 ◽  
Author(s):  
Thomas Bartl ◽  
Valentina Paspalj ◽  
Christoph Grimm
Keyword(s):  
Ovarian Cancer ◽  
Homologous Recombination ◽  
Epithelial Ovarian Cancer ◽  
Therapeutic Option ◽  
Parp Inhibitor ◽  
Therapy Response ◽  
Inhibitor Therapy ◽  
Parp Inhibition ◽  
Double Blind ◽  
Strand Breaks

SummarySince the introduction of poly-ADP-ribose polymerase (PARP) inhibitor therapy for epithelial ovarian cancer (EOC) patients, testing for aberrations of homologous recombination (HR) repair as a predictive biomarker of therapy response has become an area of particular clinical interest. As HR represents a crucial repair pathway of otherwise possibly lethal DNA double strand breaks, its deficiency triggers a phenotypic behavior of tumor cells resulting in the accumulation of genetic damage. PARP inhibitors target this emerging genomic instability by fostering DNA strand breaks. Whereas testing for mutations of the tumor-suppressor genes BRCA 1 and BRCA 2 as a pivotal part of the HR apparatus has entered clinical routine, approximately 30% more high-grade EOC patients harbor aberrations of the HR pathway other than BRCA mutations and may therefore respond to PARP inhibition therapy. In recent years, several double-blind, placebo-controlled trials investigating sizeable patient cohorts have reported positive results of PARP inhibitor therapy response in HR-positive patient subgroups. Therefore, introducing HR testing in both the primary and recurrent setting as a biomarker for PARP inhibitor response may expand the range of patients who may profit from this therapeutic option beyond BRCA-mutated tumors.

scholarly journals Gynecologic Cancers: Emerging Novel Strategies for Targeting DNA Repair Deficiency

2016 ◽  
pp. e259-e268 ◽  
Author(s):  
Rebecca S. Kristeleit ◽  
Rowan E. Miller ◽  
Elise C. Kohn
Keyword(s):  
Ovarian Cancer ◽  
Dna Repair ◽  
Brca Mutation ◽  
Parp Inhibitor ◽  
Inhibitor Therapy ◽  
Molecular Therapy ◽  
Parp Inhibition ◽  
Gynecologic Cancers ◽  
Brca Mutations ◽  
Individual Gene

The presence of a BRCA mutation, somatic or germline, is now established as a standard of care for selecting patients with ovarian cancer for treatment with a PARP inhibitor. During the clinical development of the PARP inhibitor class of agents, a subset of women without BRCA mutations were shown to respond to these drugs (termed “ BRCAness”). It was hypothesized that other genetic abnormalities causing a homologous recombinant deficiency (HRD) were sensitizing the BRCA wild-type cancers to PARP inhibition. The molecular basis for these other causes of HRD are being defined. They include individual gene defects (e.g., RAD51 mutation, CHEK2 mutation), homozygous somatic loss, and whole genome properties such as genomic scarring. Testing this knowledge is possible when selecting patients to receive molecular therapy targeting DNA repair, not only for patients with ovarian cancer but also endometrial and cervical cancers. The validity of HRD assays and multiple gene sequencing panels to select a broader population of patients for treatment with PARP inhibitor therapy is under evaluation. Other non-HRD targets for exploiting DNA repair defects in gynecologic cancers include mismatch repair (MMR), checkpoint signaling, and nonhomologous end-joining (NHEJ) DNA repair. This article describes recent evidence supporting strategies in addition to BRCA mutation for selecting patients for treatment with PARP inhibitor therapy. Additionally, the challenges and opportunities of exploiting DNA repair pathways other than homologous recombination for molecular therapy in gynecologic cancers is discussed.

scholarly journals PARP Inhibitors in Ovarian Cancer: The Route to “Ithaca”

Diagnostics ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 55 ◽  
Author(s):  
Boussios ◽  
Karathanasi ◽  
Cooke ◽  
Neille ◽  
Sadauskaite ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Dna Repair ◽  
Homologous Recombination ◽  
Brca Mutation ◽  
Parp Inhibitor ◽  
Parp Inhibitors ◽  
Parp Inhibition ◽  
Current Evidence ◽  
Repair Pathway ◽  
Significant Efficacy

Poly (ADP-ribose) polymerase (PARP) inhibitors are a novel class of therapeutic agents that target tumors with deficiencies in the homologous recombination DNA repair pathway. Genomic instability characterizes high-grade serous ovarian cancer (HGSOC), with one half of all tumors displaying defects in the important DNA repair pathway of homologous recombination. Early studies have shown significant efficacy for PARP inhibitors in patients with germline breast related cancer antigens 1 and 2 (BRCA1/2) mutations. It has also become evident that BRCA wild-type patients with other defects in the homologous recombination repair pathway benefit from this treatment. Companion homologous recombination deficiency (HRD) scores are being developed to guide the selection of patients that are most likely to benefit from PARP inhibition. The choice of which PARP inhibitor is mainly based upon the number of prior therapies and the presence of a BRCA mutation or HRD. The identification of patients most likely to benefit from PARP inhibitor therapy in view of HRD and other biomarker assessments is still challenging. The aim of this review is to describe the current evidence for PARP inhibitors in ovarian cancer, their mechanism of action, and the outstanding issues, including the rate of long-term toxicities and the evolution of resistance.

scholarly journals Efficacy of PARP Inhibitors in the Treatment of Ovarian Cancer: A Literature-Based Review

2019 ◽  
Vol 05 (01) ◽  
pp. 01-18
Author(s):  
Vikas Goswami ◽  
Venkata Pradeep Babu Koyyala ◽  
Sumit Goyal ◽  
Manish Sharma ◽  
Varun Goel ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Dna Repair ◽  
Homologous Recombination ◽  
Germ Line ◽  
Brca Mutation ◽  
Parp Inhibitor ◽  
Parp Inhibitors ◽  
Parp Inhibition ◽  
Repair Mechanism ◽  
Selection Of

AbstractPoly (ADP-ribose) polymerase (PARP) inhibitors are a unique class of therapeutic agents that focus on tumors with deficiencies in the homologous recombination DNA repair mechanism. Genomic instability outlines high-grade serous ovarian cancer, with 50% of all tumors displaying defects in the important DNA repair mechanism of homologous recombination. Earlier research studies have demonstrated considerable efficiency for PARP inhibitors in patients with germ line breast-related cancer antigens 1 and 2 (BRCA-1/BRCA-2) mutations. It has also been observed that BRCA wild-type patients with other defects in the homologous recombination repair mechanism get benefited from this therapy. Companion homologous recombination deficiency (HRD) scores are being developed to guide the selection of patients that are most likely to benefit from PARP inhibition. The selection of PARP inhibitor is mainly dependent upon the number of prior therapies and the presence of a BRCA mutation or HRD. The identification of cases which are most likely to get benefited from PARP inhibitor therapy in view of HRD and other biomarker assessments is still challenging. The purpose of this review is to focus and describe the current evidences for PARP inhibitors in ovarian malignancy, their mechanism of action, and the outstanding issues, including the rate of long-term toxicities and the evolving resistance.

scholarly journals VEGF pathway inhibition potentiates PARP inhibitor efficacy in ovarian cancer independent of BRCA status

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Francesca Bizzaro ◽  
Ilaria Fuso Nerini ◽  
Molly A. Taylor ◽  
Alessia Anastasia ◽  
Massimo Russo ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Homologous Recombination ◽  
Parp Inhibitor ◽  
Combined Treatment ◽  
Parp Inhibition ◽  
Molecular Characteristics ◽  
Homologous Recombination Repair ◽  
Mutational Status ◽  
Recombination Repair ◽  
Vegf Signalling

AbstractPoly ADP-ribose polymerase inhibitors (PARPi) have transformed ovarian cancer (OC) treatment, primarily for tumours deficient in homologous recombination repair. Combining VEGF-signalling inhibitors with PARPi has enhanced clinical benefit in OC. To study drivers of efficacy when combining PARP inhibition and VEGF-signalling, a cohort of patient-derived ovarian cancer xenografts (OC-PDXs), representative of the molecular characteristics and drug sensitivity of patient tumours, were treated with the PARPi olaparib and the VEGFR inhibitor cediranib at clinically relevant doses. The combination showed broad anti-tumour activity, reducing growth of all OC-PDXs, regardless of the homologous recombination repair (HRR) mutational status, with greater additive combination benefit in tumours poorly sensitive to platinum and olaparib. In orthotopic models, the combined treatment reduced tumour dissemination in the peritoneal cavity and prolonged survival. Enhanced combination benefit was independent of tumour cell expression of receptor tyrosine kinases targeted by cediranib, and not associated with change in expression of genes associated with DNA repair machinery. However, the combination of cediranib with olaparib was effective in reducing tumour vasculature in all the OC-PDXs. Collectively our data suggest that olaparib and cediranib act through complementary mechanisms affecting tumour cells and tumour microenvironment, respectively. This detailed analysis of the combined effect of VEGF-signalling and PARP inhibitors in OC-PDXs suggest that despite broad activity, there is no dominant common mechanistic inter-dependency driving therapeutic benefit.

scholarly journals Homologous Recombination Deficiency Assays in Epithelial Ovarian Cancer: Current Status and Future Direction

2021 ◽  
Vol 11 ◽  
Author(s):  
Ying-Cheng Chiang ◽  
Po-Han Lin ◽  
Wen-Fang Cheng
Keyword(s):  
Ovarian Cancer ◽  
Homologous Recombination ◽  
Epithelial Ovarian Cancer ◽  
Recurrent Disease ◽  
Synthetic Lethality ◽  
Parp Inhibitor ◽  
Current Status ◽  
Homologous Recombination Deficiency ◽  
Platinum Based Chemotherapy ◽  
Future Direction

Epithelial ovarian cancer (EOC) patients are generally diagnosed at an advanced stage, usually relapse after initial treatments, which include debulking surgery and adjuvant platinum-based chemotherapy, and eventually have poor 5-year survival of less than 50%. In recent years, promising survival benefits from maintenance therapy with poly(ADP-ribose) polymerase (PARP) inhibitor (PARPi) has changed the management of EOC in newly diagnosed and recurrent disease. Identification of BRCA mutations and/or homologous recombination deficiency (HRD) is critical for selecting patients for PARPi treatment. However, the currently available HRD assays are not perfect predictors of the clinical response to PARPis in EOC patients. In this review, we introduce the concept of synthetic lethality, the rationale of using PARPi when HRD is present in tumor cells, the clinical trials of PARPi incorporating the HRD assays for EOC, the current HRD assays, and other HRD assays in development.

scholarly journals Clinical significance of circulating tumor cell related markers in patients with epithelial ovarian cancer before and after adjuvant chemotherapy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Meysam Yousefi ◽  
Sara Rajaie ◽  
Vahideh Keyvani ◽  
Somayeh Bolandi ◽  
Malihe Hasanzadeh ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Adjuvant Chemotherapy ◽  
Epithelial Ovarian Cancer ◽  
Clinical Significance ◽  
Therapy Response ◽  
Serum Levels ◽  
Circulating Tumor Cell ◽  
Tumor Stage ◽  
Disease Stage ◽  
Before And After

AbstractCirculating tumor cells (CTCs) have recently been considered as new prognostic and diagnostic markers for various human cancers; however, their significance in epithelial ovarian cancer (EOC) remains to be elucidated. In this study, using quantitative real-time PCR, we evaluated the expression of EPCAM, MUC1, CEA, HE4 and CA125 mRNAs, as putative markers of CTCs, in the blood of 51 EOC patients before and/or after adjuvant chemotherapy. Our results demonstrated that, before chemotherapy, the expression of EPCAM, MUC1, CEA and HE4 mRNAs were correlated to each other. CEA expression was correlated with tumor stage (r = 0.594, p = 0.000) before chemotherapy, whereas its expression after chemotherapy was correlated with serum levels of CA125 antigen (r = 0.658, p = 0.000). HE4 mRNA showed the highest sensitivity both before and after chemotherapy (82.98% and 85.19%, respectively) and the persistence of this marker after chemotherapy was associated with advanced disease stage. The expression of CA125 mRNA had negative correlation with the other markers and with tumor stage and therapy response (evaluated by the measurement of serum CA125 antigen). Collectively, our results indicated a better clinical significance of tumor-specific markers (CEA and HE4 mRNAs) compared to epithelial-specific markers (EPCAM and MUC1 mRNAs).

Laboratory cross-comparison of homologous recombination repair mutation analysis in tumor in a multicenter epithelial ovarian cancer series: The BORNEO GEICO 60-0 study.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e17550-e17550
Author(s):  
Ignacio Romero ◽  
Ana Oaknin ◽  
Zaida Garcia-Casado ◽  
Raul Marquez ◽  
Alfonso Yubero Esteban ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Homologous Recombination ◽  
Epithelial Ovarian Cancer ◽  
Mutational Analysis ◽  
Figo Stage ◽  
Parp Inhibitors ◽  
Homologous Recombination Repair ◽  
Recombination Repair ◽  
Class 1 ◽  
Uncertain Significance

e17550 Background: In epithelial ovarian cancer (EOC), the identification of mutations in homologous recombination repair (HRR) genes on tumor is prognostic, predictive of response to PARP inhibitors, and a tool to identify individuals at genetic cancer risk. The aim of this study is to compare the concordance between two laboratories in identifying and classifying genetic variants in HRR genes. Methods: In a multicentre ambispective series of unselected, non mucinous EOC of all stages formalin-fixed and paraffin embedded tumors were collected. These samples underwent the same mutational analysis of 15 HRR genes ( ATM, BARD1, BRCA1, BRCA2, BRIP1, CDK12, CHEK1, CHEK2, FANCL, PALB2, PPP2R2A, RAD51B, RAD51C, RAD51D, RAD54L) in two different Laboratories (Lab1, Lab2) that used their own validated multi-gene NGS panels. Variant allele frequency (VAF) threshold was 5% for single nucleotide polymorphism and 10% for indels. Large rearrangements were not analyzed. Variants were classified into three categories based on ACMG criteria: non-mutated (class 1-2), Variants of Uncertain Significance (VUS: class 3) and likely pathogenic/pathogenic (class 4-5). Results: A total of 81 cases were sent for the analysis. One had low DNA quality and therefore 80 cases were finally studied (85% high grade serous and 74% FIGO stage III-IV). Results reported by Lab1 and Lab2 (lab1/Lab2) were the following: 21/19 (26%/24%) cases had BRCA1/2 mutations, 7/8 (8.7%/10%) mutations on other HRR genes including two in ATM and RAD51D, one in CHEK1, CHEK2, and FANCL and one RAD51C reported in Lab2 only while the rest were either VUS 23/27 (29%/34%) or non-mutated 29/26 (36%/33%). Concordance between laboratories in classifying patients was 93.75% (kappa coefficient 0.86). Discrepancies (DC) on variants were classified into arbitrary categories, namely 0= complete concordance, category 1 meaning DC in detection assumed to be due to tumor heterogeneity (VAF nearby the threshold) or technique (1A), or caused by laboratories performance and avoidable (1B) and the category 2 identified DC in interpretation without clinical relevance (2A) or clinically relevant (2B), the results of total number of variants are shown in table. Overall, regarding clinically relevant DC in HRR genes, 9 DC in variants were observed including six 2B, two 1A and one 1B and they affect 5 (6.3%) patients since some were overlapping. Conclusions: In our EOC series the concordance of two Laboratories in the identification of clinically relevant HRR mutations on tumor is high but discrepancies in interpretation remain a challenge that needs further harmonization.[Table: see text]

The impact of live education on the competence and performance of oncology practitioners who care for patients with ovarian cancer.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e23010-e23010
Author(s):  
Vanessa Carranza ◽  
Bryan Carson Taylor ◽  
Susan H. Gitzinger ◽  
Joan B. Fowler ◽  
Jessica Hall
Keyword(s):  
Ovarian Cancer ◽  
Genetic Testing ◽  
Cancer Patients ◽  
Parp Inhibitor ◽  
Inhibitor Therapy ◽  
Community Based ◽  
Educational Initiatives ◽  
Post Test ◽  
Chi Square Analysis

e23010 Background: About a third of ovarian cancer patients in the US have limited access to a gynecologic oncologist (GO) due to geographic disparities. A survey by The Society of Gynecologic Oncology (SGO) found that the majority of GOs found it was vital to coordinate local access to care, from diagnosis to survivorship, for patients living in areas of disparity. This allows rural/underserved patients broader access to novel therapies, as they increasingly become standard of care. It is critical for not only GOs to be current on the latest ovarian cancer data, but all clinicians who care for these patients. Methods: CEC Oncology developed two educational initiatives focused on PARP inhibitor therapy in ovarian cancer, which was targeted to all US healthcare professionals caring for ovarian cancer patients. Evaluations were collected from attendees attending an SGO Symposium and Ground Round (GR) series to assess impact on practice, increased competency, and intent to make a change in practice. Learning, knowledge, and competence was objectively assessed by analyzing pre-test, post-test, and follow-up survey data (sent 4-6 weeks post-activity). Chi-square analysis was conducted with a priori significance set at 0.05. Results: A total of 830 clinicians were educated, with SGO attendees primarily practicing in academic settings and GR attendees mostly from community practices. SGO attendees were asked case questions at baseline, immediately after the activity, and 4-6 weeks after the activity. Knowledge increased from pre- to post-test regarding current genetic testing recommendations (23% increase; P= .004) and appropriate selection of PARP inhibitor therapy (25% increase; P= .017). Knowledge was sustained at follow-up analysis. At follow-up, 90% of SGO and 84% of GR attendees made a change as a result of attending the activities. More attendees were able to incorporate germline multigene testing into practice, than originally intended; increase of 29% for SGO and 7% for GR audiences. All attendees experienced the barrier lack of patient education about the importance of genetic testing/counseling more than anticipated; increase of 7% for SGO and 13% for GR audiences. At follow-up, there was a 9% increase in GR attendees listing staying current with trial data and practice guidelines as a barrier. Conclusions: There were some notable differences seen in competence/performance among attendees of the two ovarian cancer educational initiatives. Differences may be attributed to practice setting (SGO primarily academic; GR primarily community.) Overall, GR attendees were more likely to face barriers, suggesting that community-based clinicians have fewer resources and experience more barriers to implementing best practices. Thus, it is vital to offer education for clinicians in community-based practices, particularly in areas that are considered ‘geographically disparate’.

Sign in / Sign up

Export Citation Format

Share Document