Gene Summary

Gene:RAD51C; RAD51 paralog C
Aliases: FANCO, R51H3, BROVCA3, RAD51L2
Summary:This gene is a member of the RAD51 family. RAD51 family members are highly similar to bacterial RecA and Saccharomyces cerevisiae Rad51 and are known to be involved in the homologous recombination and repair of DNA. This protein can interact with other RAD51 paralogs and is reported to be important for Holliday junction resolution. Mutations in this gene are associated with Fanconi anemia-like syndrome. This gene is one of four localized to a region of chromosome 17q23 where amplification occurs frequently in breast tumors. Overexpression of the four genes during amplification has been observed and suggests a possible role in tumor progression. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2013]
Databases:OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:DNA repair protein RAD51 homolog 3
Source:NCBIAccessed: 30 August, 2019


What does this gene/protein do?
Show (19)

Cancer Overview

Research Indicators

Publications Per Year (1994-2019)
Graph generated 31 August 2019 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

  • Genetic Testing
  • Genetic Predisposition
  • Antineoplastic Agents
  • Sequence Homology
  • Hereditary Breast and Ovarian Cancer Syndrome
  • Drug Resistance
  • DNA Mutational Analysis
  • Fanconi Anaemia
  • Genetic Association Studies
  • Missense Mutation
  • Stomach Cancer
  • BRCA2
  • Exons
  • BRCA1
  • BRCA1 Protein
  • Ovarian Cancer
  • Germ-Line Mutation
  • Platinum Compounds
  • DNA-Binding Proteins
  • Fanconi Anemia Complementation Group Proteins
  • Nuclear Proteins
  • Glandular and Epithelial Cancers
  • Mutation
  • Fanconi Anemia Complementation Group N Protein
  • CHEK2
  • Staging
  • BRCA2 Protein
  • High-Throughput Nucleotide Sequencing
  • Case-Control Studies
  • Subcellular Fractions
  • Chromosome 17
  • Biomarkers, Tumor
  • T-Box Domain Proteins
  • DNA Damage
  • Carcinoma, Ovarian Epithelial
  • Cancer Gene Expression Regulation
  • Rad51 Recombinase
  • Alleles
  • DNA Repair
  • Breast Cancer
Tag cloud generated 30 August, 2019 using data from PubMed, MeSH and CancerIndex

Specific Cancers (6)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: RAD51C (cancer-related)

Shahi RB, De Brakeleer S, Caljon B, et al.
Identification of candidate cancer predisposing variants by performing whole-exome sequencing on index patients from BRCA1 and BRCA2-negative breast cancer families.
BMC Cancer. 2019; 19(1):313 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: In the majority of familial breast cancer (BC) families, the etiology of the disease remains unresolved. To identify missing BC heritability resulting from relatively rare variants (minor allele frequency ≤ 1%), we have performed whole exome sequencing followed by variant analysis in a virtual panel of 492 cancer-associated genes on BC patients from BRCA1 and BRCA2 negative families with elevated BC risk.
METHODS: BC patients from 54 BRCA1 and BRCA2-negative families with elevated BC risk and 120 matched controls were considered for germline DNA whole exome sequencing. Rare variants identified in the exome and in a virtual panel of cancer-associated genes [492 genes associated with different types of (hereditary) cancer] were compared between BC patients and controls. Nonsense, frame-shift indels and splice-site variants (strong protein-damaging variants, called PDAVs later on) observed in BC patients within the genes of the panel, which we estimated to possess the highest probability to predispose to BC, were further validated using an alternative sequencing procedure.
RESULTS: Exome- and cancer-associated gene panel-wide variant analysis show that there is no significant difference in the average number of rare variants found in BC patients compared to controls. However, the genes in the cancer-associated gene panel with nonsense variants were more than two-fold over-represented in women with BC and commonly involved in the DNA double-strand break repair process. Approximately 44% (24 of 54) of BC patients harbored 31 PDAVs, of which 11 were novel. These variants were found in genes associated with known or suspected BC predisposition (PALB2, BARD1, CHEK2, RAD51C and FANCA) or in predisposing genes linked to other cancer types but not well-studied in the context of familial BC (EXO1, RECQL4, CCNH, MUS81, TDP1, DCLRE1A, DCLRE1C, PDE11A and RINT1) and genes associated with different hereditary syndromes but not yet clearly associated with familial cancer syndromes (ABCC11, BBS10, CD96, CYP1A1, DHCR7, DNAH11, ESCO2, FLT4, HPS6, MYH8, NME8 and TTC8). Exome-wide, only a few genes appeared to be enriched for PDAVs in the familial BC patients compared to controls.
CONCLUSIONS: We have identified a series of novel candidate BC predisposition variants/genes. These variants/genes should be further investigated in larger cohorts/case-control studies. Other studies including co-segregation analyses in affected families, locus-specific loss of heterozygosity and functional studies should shed further light on their relevance for BC risk.

Morse CB, Toukatly MN, Kilgore MR, et al.
Tumor infiltrating lymphocytes and homologous recombination deficiency are independently associated with improved survival in ovarian carcinoma.
Gynecol Oncol. 2019; 153(2):217-222 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
OBJECTIVE: The presence of tumor infiltrating lymphocytes (TIL) and defects in homologous recombination (HR) are each important prognostic factors in ovarian carcinoma (OC). We characterized the association between HR deficiency (HRD) and the presence of TILs in a cohort of OC patients and the relative contribution to overall survival.
METHODS: Patients with carcinoma of the ovary, fallopian tube, or peritoneum were prospectively enrolled. Malignant neoplasm and serum samples were collected. Immunohistochemistry for CD3+ T cells and CD68+ tumor associated macrophages (TAMs) was performed on specimens collected at primary surgery. Damaging germline and somatic mutations in genes in the HR-mediated repair (HRR) pathway were identified using BROCA sequencing. HRD was defined as a damaging mutation in one of 12 genes in the HRR pathway or promoter hypermethylation in BRCA1 or RAD51C.
RESULTS: Ninety-eight of 250 patients included in the analysis had HRD OC (39.2%). HRD OC were enriched for CD3+ TILs and CD68+ TAMs. High CD3+ TIL was present in 65.3% of HRD OC compared to 43.4% of non-HRD OC (P = 0.001). High CD68+ TAM was present in 66.3% of HRD OC compared to 50.7% of non-HRD OC (P = 0.015). Patients with HRD OC and high CD3+ TILs had the longest median overall survival compared to non-HRD OC with low CD3+ TILs (70.9 vs. 35.8 months, adjusted HR 0.38, 95% CI (0.25-0.59)).
CONCLUSIONS: Patients that have both CD3+ TILs and HRD OC are afforded the greatest improvement in overall survival. This finding may have therapeutic implications for OC patients treated with emerging immunotherapies.

Suszynska M, Klonowska K, Jasinska AJ, Kozlowski P
Large-scale meta-analysis of mutations identified in panels of breast/ovarian cancer-related genes - Providing evidence of cancer predisposition genes.
Gynecol Oncol. 2019; 153(2):452-462 [PubMed] Related Publications
OBJECTIVE: Germline mutations occurring in the highly penetrant genes BRCA1 and BRCA2 are responsible for only certain cases of familial breast cancer (BC) and ovarian cancer (OC). Thus, the use of NGS multi-gene panel (MGP) testing has recently become very popular.
METHODS: To estimate a reliable BC and OC risk associated with pathogenic variants in the selected candidate BC/OC predisposition genes, a comprehensive meta-analysis of 48 MGP-based studies analyzing BC/OC patients was conducted. The role of 37 genes was evaluated, comparing, in total, the mutation frequency in ~120,000 BC/OC cases and ~120,000 controls, which guaranteed strong statistical support with high confidence for most analyzed genes.
RESULTS: We characterized the strategies of MGP analyses and the types and localizations of the identified mutations and showed that 13 and 11 of the analyzed genes were significantly associated with an increased BC and OC risk, respectively. The risk attributed to some of these genes (e.g., CDKN2A and PALB2 for BC) was similar to that observed for BRCA2. The analysis also showed a substantial difference in the profile of genes contributing to either BC or OC risk, including genes specifically associated with a high risk of OC but not BC (e.g., RAD51C, and RAD51D).
CONCLUSIONS: Our study provides strong statistical proof, defines the risk for many genes often considered candidates for BC/OC predisposition and excludes the role of other genes frequently analyzed in the MGPs. In the context of clinical diagnostics, the results support the knowledge-based interpretation of identified mutations.

Krivokuca A, Boljevic I, Jovandic S, et al.
Germline mutations in cancer susceptibility genes in high grade serous ovarian cancer in Serbia.
J Hum Genet. 2019; 64(4):281-290 [PubMed] Related Publications
Clinical criteria for genetic testing of genes other than BRCA1/2 in epithelial ovarian cancer (EOC) still do not exist. We assessed the frequency and predictors of deleterious mutations in 19 cancer predisposition genes in high-grade serous ovarian cancer (HGSOC) in Serbia. Next-generation sequencing was used to identify germline mutations in the whole coding regions of a gene panel. Patients' characteristics and sequencing data were summarized with descriptive statistics and compared using chi-square test. Among 131 HGSOC patients, 23 had BRCA1 (17.6%) while 5 had BRCA2 (3.8%) mutation. In addition, 9 (6.9%) pathogenic mutations were detected in other genes including BRIP1 (n = 2;1.5%), CHEK2 (n = 2;1.5%), NBN (n = 3;2.3%) and RAD51C (n = 2;1.5%). Factors that predicted for BRCA1/2 mutations were: breast and ovarian cancers in the same patient (p = 0.031), young age of EOC (p = 0.029), menstrual status (p = 0.004) and family history of cancer (p < 0.0001). However, these factors did not predict for mutations in other cancer susceptibility genes. Applying established referral criteria for genetic testing in Serbia will help identify BRCA1/2 mutation carriers but will not help identify mutations in other cancer susceptibility genes. Until better predictors emerge we should be performing wider genetic testing of EOC in order to identify all mutation carriers.

Potugari BR, Engel JM, Onitilo AA
Metastatic Prostate Cancer in a
Clin Med Res. 2018; 16(3-4):69-72 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
A man, aged 61 years, with a history of hypogonadism and family history of cancer experienced persistent urinary difficulties with no visible prostate abnormalities. Laboratory testing and diagnostic imaging revealed a primary lesion in the prostate with lymph node involvement and multiple bone metastases. Treatment with androgen-deprivation therapy, 17,20-lyase inhibition, and bisphosphonates for 7 months was unsuccessful in preventing disease progression, but second-line chemotherapy and continued androgen-deprivation therapy improved prostate specific antigen levels. During the patient's second treatment regimen, his daughter received a diagnosis of breast cancer. The patient's daughter underwent genetic testing for oncogenic mutations, and it was discovered that she carried a mutation in

Donenberg T, George S, Ali J, et al.
A clinically structured and partnered approach to genetic testing in Trinidadian women with breast cancer and their families.
Breast Cancer Res Treat. 2019; 174(2):469-477 [PubMed] Related Publications
INTRODUCTION: Breast cancer (BC) is the leading cause of cancer death in Caribbean women. Across the Caribbean islands, the prevalence of hereditary breast cancer among unselected breast cancer patients ranges from 5 to 25%. Moreover, the prevalence of BC among younger women and the high mortality in the Caribbean region are notable. This BC burden presents an opportunity for cancer prevention and control that begins with genetic testing among high-risk women. Measured response to positive genetic test results includes the number of preventive procedures and cascade testing in family members. We previously reported data on an active approach to promote cascade testing in the Bahamas and report on preventive procedures showing moderate uptake. Here, we describe a clinically structured and community-partnered approach to the dissemination and follow-up of genetic test results including family counseling for the promotion of risk mitigation strategies and cascade testing in our Trinidadian cohort of patients tested positive for BC predisposition genes.
METHODS: As a part of our initial study of BC genetic testing in Trinidad and Tobago, all participants received pre-test counseling including three-generation pedigree and genetic testing for BRCA1/2, PALB2, and RAD51C. The study was approved by the University of Miami IRB and the Ethics Committee of the Ministry of Health, Trinidad and Tobago. We prospectively evaluated a clinically structured approach to genetic counseling and follow-up of BC mutation carriers in Trinidad and Tobago in 2015. The intervention consisted of (1) engaging twenty-nine BC patients with a deleterious gene mutation (probands), and (2) invitation of their at-risk relatives to attend to a family counseling session. The session included information on the meaning of their results, risk of inheritance, risk of cancer, risk-reduction options, offering of cascade testing to family members, and follow-up of proband decision-making over two years.
RESULTS: Twenty-four of twenty-nine mutation carriers (82.8%) consented to enroll in the study. At initial pedigree review, we identified 125 at-risk relatives (ARR). Seventy-seven ARR (62%) attended the family counseling sessions; of these, 76 ARR (99%) consented to be tested for their family gene mutation. Genetic sequencing revealed that of the 76 tested, 35 (46%) ARR were carriers of their family mutation. The ARR received their results and were urged to take preventative measures at post-test counseling. At 2-year follow-up, 6 of 21 probands with intact breasts elected to pursue preventive mastectomy (28.5%) and 4 of 20 women with intact ovaries underwent RRSO (20%).
CONCLUSIONS: In Trinidad and Tobago, a clinically structured and partnered approach to our testing program led to a significant rate of proband response by completing the intervention counseling session, executing risk-reducing procedures as well as informing and motivating at-risk relatives, thereby demonstrating the utility and efficacy of this BC control program.

Hoyer J, Vasileiou G, Uebe S, et al.
Addition of triple negativity of breast cancer as an indicator for germline mutations in predisposing genes increases sensitivity of clinical selection criteria.
BMC Cancer. 2018; 18(1):926 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
BACKGROUND: Breast cancer is the most common cancer in women. 12-15% of all tumors are triple-negative breast cancers (TNBC). So far, TNBC has been mainly associated with mutations in BRCA1. The presence of other predisposing genes seems likely since DNA damage repair is a complex process that involves several genes. Therefore we investigated if mutations in other genes are involved in cancer development and whether TNBC is an additional indicator of mutational status besides family history and age of onset.
METHODS: We performed a germline panel-based screening of 10 high and low-moderate penetrance breast cancer susceptibility genes (BRCA1, BRCA2, ATM, CDH1, CHEK2, NBN, PALB2, RAD51C, RAD51D and TP53) in 229 consecutive individuals affected with TNBC unselected for age, family history or bilateral disease. Within this cohort we compared the number of mutation carriers fulfilling clinical selection criteria with the total number of carriers identified.
RESULTS: Age at diagnosis ranged from 23 to 80 years with an average age of 50.2 years. In 57 women (24.9%) we detected a pathogenic mutation, with a higher frequency (29.7%) in the group manifesting cancer before 60 years. Deleterious BRCA1 mutations occurred in 14.8% of TNBC patients. These were predominantly recurrent frameshift mutations (24/34, 70.6%). Deleterious BRCA2 mutations occurred in 5.7% of patients, all but one (c.1813dupA) being unique. While no mutations were found in CDH1 and TP53, 10 mutations were detected in one of the six other predisposition genes. Remarkably, neither of the ATM, RAD51D, CHEK2 and PALB2 mutation carriers had a family history. Furthermore, patients with non-BRCA1/2 mutations were not significantly younger than mutation negative women (p = 0.3341). Most importantly, among the 57 mutation carriers, ten (17.5%) would be missed using current clinical testing criteria including five (8%) with BRCA1/2 mutations.
CONCLUSIONS: In summary, our data confirm and expand previous studies of a high frequency of germline mutations in genes associated with ineffective repair of DNA damage in women with TNBCs. Neither age of onset, contralateral disease nor family history were able to discern all mutation positive individuals. Therefore, TNBC should be considered as an additional criterion for panel based genetic testing.

Marshall CH, Fu W, Wang H, et al.
Prevalence of DNA repair gene mutations in localized prostate cancer according to clinical and pathologic features: association of Gleason score and tumor stage.
Prostate Cancer Prostatic Dis. 2019; 22(1):59-65 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
BACKGROUND: DNA repair gene mutations are present in 8-10% of localized prostate cancers. It is unknown whether this is influenced by clinicopathologic factors.
METHODS: We interrogated localized prostate adenocarcinomas with tumor DNA sequencing information from the TCGA validated (n = 333) and Nature Genetics (n = 377) datasets. Homologous recombination repair genes included in our analysis were: ATM, BRCA1/2, CDK12, CHEK1/2, FANCA, FANCD2, FANCL, GEN1, NBN, PALB2, RAD51, and RAD51C. Proportions of cases with pathogenic DNA repair mutations (and in ATM/BRCA1/2 specifically) were reported by Gleason grade group, clinical T, pathologic T, and pathologic N stage. Odds ratios and Fisher's exact tests were used to compare proportions between categories.
RESULTS: Patients with Gleason grade groups 3 and higher were 2.2 times more likely to harbor any DNA repair mutation (95% CI: 1.2-4.2; 10.3% versus 5.0%) and were 2.7 times more likely to have BRCA1/2 or ATM mutations (95% CI: 1.3-6.6; 7.0% versus 2.7%) compared to those in Gleason grade groups 1-2. Patients with pathologic T3 and T4 stage (pT3/pT4) were 2.6 times more likely to have any DNA repair mutation (95% CI: 1.3-6.6; 13.0% versus 5.5%) and were 3.2 times more likely to have BRCA1/2 or ATM mutations (95% CI: 1.2-11.3; 9.5% versus 3.1%) compared to those with pT2 disease. There was no difference by clinical tumor or nodal stage. Among men with Gleason grade group ≥ 3 and clinical stage ≥ cT3, 21.3% (1 in 5) had a DNA repair mutation in any gene and 11.7% (1 in 9) had a mutation in ATM/BRCA1/2.
CONCLUSIONS: The prevalence of pathogenic DNA repair gene alterations is enriched in men with advanced tumor stages and higher Gleason grade groups, with maximal enrichment observed in those with Gleason grade group ≥ 3 and clinical stage ≥ cT3 disease. This information can be used to guide eligibility criteria for genomically targeted clinical trials in the neoadjuvant/adjuvant settings.

Castéra L, Harter V, Muller E, et al.
Landscape of pathogenic variations in a panel of 34 genes and cancer risk estimation from 5131 HBOC families.
Genet Med. 2018; 20(12):1677-1686 [PubMed] Related Publications
PURPOSE: Integration of gene panels in the diagnosis of hereditary breast and ovarian cancer (HBOC) requires a careful evaluation of the risk associated with pathogenic or likely pathogenic variants (PVs) detected in each gene. Here we analyzed 34 genes in 5131 suspected HBOC index cases by next-generation sequencing.
METHODS: Using the Exome Aggregation Consortium data sets plus 571 individuals from the French Exome Project, we simulated the probability that an individual from the Exome Aggregation Consortium carries a PV and compared it to the estimated frequency within the HBOC population.
RESULTS: Odds ratio conferred by PVs within BRCA1, BRCA2, PALB2, RAD51C, RAD51D, ATM, BRIP1, CHEK2, and MSH6 were estimated at 13.22 [10.01-17.22], 8.61 [6.78-10.82], 8.22 [4.91-13.05], 4.54 [2.55-7.48], 5.23 [1.46-13.17], 3.20 [2.14-4.53], 2.49 [1.42-3.97], 1.67 [1.18-2.27], and 2.50 [1.12-4.67], respectively. PVs within RAD51C, RAD51D, and BRIP1 were associated with ovarian cancer family history (OR = 11.36 [5.78-19.59], 12.44 [2.94-33.30] and 3.82 [1.66-7.11]). PALB2 PVs were associated with bilateral breast cancer (OR = 16.17 [5.48-34.10]) and BARD1 PVs with triple-negative breast cancer (OR = 11.27 [3.37-25.01]). Burden tests performed in both patients and the French Exome Project population confirmed the association of PVs of BRCA1, BRCA2, PALB2, and RAD51C with HBOC.
CONCLUSION: Our results validate the integration of PALB2, RAD51C, and RAD51D in the diagnosis of HBOC and suggest that the other genes are involved in an oligogenic determinism.

Yurgelun MB, Chittenden AB, Morales-Oyarvide V, et al.
Germline cancer susceptibility gene variants, somatic second hits, and survival outcomes in patients with resected pancreatic cancer.
Genet Med. 2019; 21(1):213-223 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
PURPOSE: Germline variants in double-strand DNA damage repair (dsDDR) genes (e.g., BRCA1/2) predispose to pancreatic adenocarcinoma (PDAC) and may predict sensitivity to platinum-based chemotherapy and poly(ADP) ribose polymerase (PARP) inhibitors. We sought to determine the prevalence and significance of germline cancer susceptibility gene variants in PDAC with paired somatic and survival analyses.
METHODS: Using a customized next-generation sequencing panel, germline/somatic DNA was analyzed from 289 patients with resected PDAC ascertained without preselection for high-risk features (e.g., young age, personal/family history). All identified variants were assessed for pathogenicity. Outcomes were analyzed using multivariable-adjusted Cox proportional hazards regression.
RESULTS: We found that 28/289 (9.7%; 95% confidence interval [CI] 6.5-13.7%) patients carried pathogenic/likely pathogenic germline variants, including 21 (7.3%) dsDDR gene variants (3 BRCA1, 4 BRCA2, 14 other dsDDR genes [ATM, BRIP1, CHEK2, NBN, PALB2, RAD50, RAD51C]), 3 Lynch syndrome, and 4 other genes (APC p.I1307K, CDKN2A, TP53). Somatic sequencing and immunohistochemistry identified second hits in the tumor in 12/27 (44.4%) patients with germline variants (1 failed sequencing). Compared with noncarriers, patients with germline dsDDR gene variants had superior overall survival (hazard ratio [HR] 0.54; 95% CI 0.30-0.99; P = 0.05).
CONCLUSION: Nearly 10% of PDAC patients harbor germline variants, although the majority lack somatic second hits, the therapeutic significance of which warrants further study.

Paulo P, Maia S, Pinto C, et al.
Targeted next generation sequencing identifies functionally deleterious germline mutations in novel genes in early-onset/familial prostate cancer.
PLoS Genet. 2018; 14(4):e1007355 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
Considering that mutations in known prostate cancer (PrCa) predisposition genes, including those responsible for hereditary breast/ovarian cancer and Lynch syndromes, explain less than 5% of early-onset/familial PrCa, we have sequenced 94 genes associated with cancer predisposition using next generation sequencing (NGS) in a series of 121 PrCa patients. We found monoallelic truncating/functionally deleterious mutations in seven genes, including ATM and CHEK2, which have previously been associated with PrCa predisposition, and five new candidate PrCa associated genes involved in cancer predisposing recessive disorders, namely RAD51C, FANCD2, FANCI, CEP57 and RECQL4. Furthermore, using in silico pathogenicity prediction of missense variants among 18 genes associated with breast/ovarian cancer and/or Lynch syndrome, followed by KASP genotyping in 710 healthy controls, we identified "likely pathogenic" missense variants in ATM, BRIP1, CHEK2 and TP53. In conclusion, this study has identified putative PrCa predisposing germline mutations in 14.9% of early-onset/familial PrCa patients. Further data will be necessary to confirm the genetic heterogeneity of inherited PrCa predisposition hinted in this study.

Böck J, Appenzeller S, Haertle L, et al.
Single CpG hypermethylation, allele methylation errors, and decreased expression of multiple tumor suppressor genes in normal body cells of mutation-negative early-onset and high-risk breast cancer patients.
Int J Cancer. 2018; 143(6):1416-1425 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
To evaluate the role of constitutive epigenetic changes in normal body cells of BRCA1/BRCA2-mutation negative patients, we have developed a deep bisulfite sequencing assay targeting the promoter regions of 8 tumor suppressor (TS) genes (BRCA1, BRCA2, RAD51C, ATM, PTEN, TP53, MLH1, RB1) and the estrogene receptor gene (ESR1), which plays a role in tumor progression. We analyzed blood samples of two breast cancer (BC) cohorts with early onset (EO) and high risk (HR) for a heterozygous mutation, respectively, along with age-matched controls. Methylation analysis of up to 50,000 individual DNA molecules per gene and sample allowed quantification of epimutations (alleles with >50% methylated CpGs), which are associated with epigenetic silencing. Compared to ESR1, which is representative for an average promoter, TS genes were characterized by a very low (< 1%) average methylation level and a very low mean epimutation rate (EMR; < 0.0001% to 0.1%). With exception of BRCA1, which showed an increased EMR in BC (0.31% vs. 0.06%), there was no significant difference between patients and controls. One of 36 HR BC patients exhibited a dramatically increased EMR (14.7%) in BRCA1, consistent with a disease-causing epimutation. Approximately one third (15 of 44) EO BC patients exhibited increased rates of single CpG methylation errors in multiple TS genes. Both EO and HR BC patients exhibited global underexpression of blood TS genes. We propose that epigenetic abnormalities in normal body cells are indicative of disturbed mechanisms for maintaining low methylation and appropriate expression levels and may be associated with an increased BC risk.

Hauke J, Horvath J, Groß E, et al.
Gene panel testing of 5589 BRCA1/2-negative index patients with breast cancer in a routine diagnostic setting: results of the German Consortium for Hereditary Breast and Ovarian Cancer.
Cancer Med. 2018; 7(4):1349-1358 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
The prevalence of germ line mutations in non-BRCA1/2 genes associated with hereditary breast cancer (BC) is low, and the role of some of these genes in BC predisposition and pathogenesis is conflicting. In this study, 5589 consecutive BC index patients negative for pathogenic BRCA1/2 mutations and 2189 female controls were screened for germ line mutations in eight cancer predisposition genes (ATM, CDH1, CHEK2, NBN, PALB2, RAD51C, RAD51D, and TP53). All patients met the inclusion criteria of the German Consortium for Hereditary Breast and Ovarian Cancer for germ line testing. The highest mutation prevalence was observed in the CHEK2 gene (2.5%), followed by ATM (1.5%) and PALB2 (1.2%). The mutation prevalence in each of the remaining genes was 0.3% or lower. Using Exome Aggregation Consortium control data, we confirm significant associations of heterozygous germ line mutations with BC for ATM (OR: 3.63, 95%CI: 2.67-4.94), CDH1 (OR: 17.04, 95%CI: 3.54-82), CHEK2 (OR: 2.93, 95%CI: 2.29-3.75), PALB2 (OR: 9.53, 95%CI: 6.25-14.51), and TP53 (OR: 7.30, 95%CI: 1.22-43.68). NBN germ line mutations were not significantly associated with BC risk (OR:1.39, 95%CI: 0.73-2.64). Due to their low mutation prevalence, the RAD51C and RAD51D genes require further investigation. Compared with control datasets, predicted damaging rare missense variants were significantly more prevalent in CHEK2 and TP53 in BC index patients. Compared with the overall sample, only TP53 mutation carriers show a significantly younger age at first BC diagnosis. We demonstrate a significant association of deleterious variants in the CHEK2, PALB2, and TP53 genes with bilateral BC. Both, ATM and CHEK2, were negatively associated with triple-negative breast cancer (TNBC) and estrogen receptor (ER)-negative tumor phenotypes. A particularly high CHEK2 mutation prevalence (5.2%) was observed in patients with human epidermal growth factor receptor 2 (HER2)-positive tumors.

Sánchez-Bermúdez AI, Sarabia-Meseguer MD, García-Aliaga Á, et al.
Mutational analysis of RAD51C and RAD51D genes in hereditary breast and ovarian cancer families from Murcia (southeastern Spain).
Eur J Med Genet. 2018; 61(6):355-361 [PubMed] Related Publications
RAD51C and RAD51D have been defined as susceptibility genes for hereditary breast and ovarian cancer syndrome in several studies. In the present study, a mutation analysis of these genes was performed on non BRCA1/2 families. RAD51C and RAD51D genes were analyzed in 141 and 77 families, respectively. The analysis included direct sequencing and multiple ligation probe analysis. The RAD51C pathogenic variant c.404G > A was identified in a breast and ovarian cancer family (0.7%), while the RAD51D pathogenic variant c.694C > T was described in an ovarian cancer family (1.3%). Moreover, three unknown clinical significance variants were detected: c.307T > G in RAD51C, and c.413A > G and c.715C > T in RAD51D. No large genomic rearrangements (LGRs) were found. RAD51D carriers suffered from premenopausal ovarian tumors. These results increase our knowledge about the RAD51C and RAD51D mutation spectrum and support the notion that these genes should be included in the gene panel testing performed on patients with hereditary breast and ovarian cancer syndrome.

Manchanda R, Patel S, Gordeev VS, et al.
Cost-effectiveness of Population-Based BRCA1, BRCA2, RAD51C, RAD51D, BRIP1, PALB2 Mutation Testing in Unselected General Population Women.
J Natl Cancer Inst. 2018; 110(7):714-725 [PubMed] Related Publications
Background: The cost-effectiveness of population-based panel testing for high- and moderate-penetrance ovarian cancer (OC)/breast cancer (BC) gene mutations is unknown. We evaluate the cost-effectiveness of population-based BRCA1/BRCA2/RAD51C/RAD51D/BRIP1/PALB2 mutation testing compared with clinical criteria/family history (FH) testing in unselected general population women.
Methods: A decision-analytic model comparing lifetime costs and effects of criteria/FH-based BRCA1/BRCA2 testing is compared with BRCA1/BRCA2/RAD51C/RAD51D/BRIP1/PALB2 testing in those fulfilling clinical criteria/strong FH of cancer (≥10% BRCA1/BRCA2 probability) and all women age 30 years or older. Analyses are presented for UK and US populations. Identified carriers undergo risk-reducing salpingo-oophorectomy. BRCA1/BRCA2/PALB2 carriers can opt for magnetic resonance imaging/mammography, chemoprevention, or risk-reducing mastectomy. One-way and probabilistic sensitivity analysis (PSA) enabled model uncertainty evaluation. Outcomes include OC, BC, and additional heart disease deaths. Quality-adjusted life-years (QALYs), OC incidence, BC incidence, and incremental cost-effectiveness ratio (ICER) were calculated. The time horizon is lifetime and perspective is payer.
Results: Compared with clinical criteria/FH-based BRCA1/BRCA2 testing, clinical criteria/FH-based BRCA1/BRCA2/RAD51C/RAD51D/BRIP1/PALB2 testing is cost-effective (ICER = £7629.65/QALY or $49 282.19/QALY; 0.04 days' life-expectancy gained). Population-based testing for BRCA1/BRCA2/RAD51C/RAD51D/BRIP1/PALB2 mutations is the most cost-effective strategy compared with current policy: ICER = £21 599.96/QALY or $54 769.78/QALY (9.34 or 7.57 days' life-expectancy gained). At £30 000/QALY and $100 000/QALY willingness-to-pay thresholds, population-based BRCA1/BRCA2/RAD51C/RAD51D/BRIP1/PALB2 panel testing is the preferred strategy in 83.7% and 92.7% of PSA simulations; criteria/FH-based panel testing is preferred in 16.2% and 5.8% of simulations, respectively. Population-based BRCA1/BRCA2/RAD51C/RAD51D/BRIP1/PALB2 testing can prevent 1.86%/1.91% of BC and 3.2%/4.88% of OC in UK/US women: 657/655 OC cases and 2420/2386 BC cases prevented per million.
Conclusions: Population-based BRCA1/BRCA2/RAD51C/RAD51D/BRIP1/PALB2 testing is more cost-effective than any clinical criteria/FH-based strategy. Clinical criteria/FH-based BRCA1/BRCA2/RAD51C/RAD51D/BRIP1/PALB2 testing is more cost-effective than BRCA1/BRCA2 testing alone.

Guo X, Shi J, Cai Q, et al.
Use of deep whole-genome sequencing data to identify structure risk variants in breast cancer susceptibility genes.
Hum Mol Genet. 2018; 27(5):853-859 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
Functional disruptions of susceptibility genes by large genomic structure variant (SV) deletions in germlines are known to be associated with cancer risk. However, few studies have been conducted to systematically search for SV deletions in breast cancer susceptibility genes. We analysed deep (> 30x) whole-genome sequencing (WGS) data generated in blood samples from 128 breast cancer patients of Asian and European descent with either a strong family history of breast cancer or early cancer onset disease. To identify SV deletions in known or suspected breast cancer susceptibility genes, we used multiple SV calling tools including Genome STRiP, Delly, Manta, BreakDancer and Pindel. SV deletions were detected by at least three of these bioinformatics tools in five genes. Specifically, we identified heterozygous deletions covering a fraction of the coding regions of BRCA1 (with approximately 80kb in two patients), and TP53 genes (with ∼1.6 kb in two patients), and of intronic regions (∼1 kb) of the PALB2 (one patient), PTEN (three patients) and RAD51C genes (one patient). We confirmed the presence of these deletions using real-time quantitative PCR (qPCR). Our study identified novel SV deletions in breast cancer susceptibility genes and the identification of such SV deletions may improve clinical testing.

Golmard L, Castéra L, Krieger S, et al.
Contribution of germline deleterious variants in the RAD51 paralogs to breast and ovarian cancers.
Eur J Hum Genet. 2017; 25(12):1345-1353 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
RAD51 paralogs (RAD51B, RAD51C, RAD51D, XRCC2, and XRCC3) have recently been involved in breast and ovarian cancer predisposition: RAD51B, RAD51C, and RAD51D in ovarian cancer, RAD51B and XRCC2 in breast cancer. The aim of this study was to estimate the contribution of deleterious variants in the five RAD51 paralogs to breast and ovarian cancers. The five RAD51 paralog genes were analyzed by next-generation sequencing technologies in germline DNA from 2649 consecutive patients diagnosed with breast and/or ovarian cancer. Twenty-one different deleterious variants were identified in the RAD51 paralogs in 30 patients: RAD51B (n = 4), RAD51C (n = 12), RAD51D (n = 7), XRCC2 (n = 2), and XRCC3 (n = 5). The overall deleterious variant rate was 1.13% (95% confidence interval (CI): 0.72-1.55%) (30/2649), including 15 variants in breast cancer only cases (15/2063; 0.73% (95% CI: 0.34-1.11%)) and 15 variants in cases with at least one ovarian cancer (15/570; 2.63% (95% CI: 1.24-4.02%)). This study is the first evaluation of the five RAD51 paralogs in breast and ovarian cancer predisposition and it demonstrates that deleterious variants can be present in breast cancer only cases. Moreover, this is the first time that XRCC3 deleterious variants have been identified in breast and ovarian cancer cases.

Manchanda R, Menon U
Setting the Threshold for Surgical Prevention in Women at Increased Risk of Ovarian Cancer.
Int J Gynecol Cancer. 2018; 28(1):34-42 [PubMed] Related Publications
The number of ovarian cancer cases is predicted to rise by 14% in Europe and 55% worldwide over the next 2 decades. The current absence of a screening program, rising drug/treatment costs, and only marginal improvements in survival seen over the past 30 years suggest the need for maximizing primary surgical prevention to reduce the burden of ovarian cancer. Primary surgical prevention through risk-reducing salpingo-oophorectomy (RRSO) is well established as the most effective method for preventing ovarian cancer. In the UK, it has traditionally been offered to high-risk women (>10% lifetime risk of ovarian cancer) who have completed their family. The cost-effectiveness of RRSO in BRCA1/BRCA2 carriers older than 35 years is well established. Recently, RRSO has been shown to be cost-effective in postmenopausal women at lifetime ovarian cancer risks of 5% or greater and in premenopausal women at lifetime risks greater than 4%. The acceptability, uptake, and satisfaction with RRSO at these intermediate-risk levels remain to be established. Prospective outcome data on risk-reducing salpingectomy and delayed-oophorectomy for preventing ovarian cancer is lacking, and hence, this is best offered for primary prevention within the context and safe environment of a clinical trial. An estimated 63% of ovarian cancers occur in women with greater than 4% lifetime risk and 53% in those with 5% or greater lifetime-risk. Risk-reducing salpingo-oophorectomy can be offered for primary surgical prevention to women at intermediate risk levels (4%-5% to 10%). This includes unaffected women who have completed their family and have RAD51C, RAD51D, or BRIP1 gene mutations; first-degree relatives of women with invasive epithelial ovarian cancer; BRCA mutation-negative women from high-risk breast-and-ovarian cancer or ovarian-cancer-only families. In those with BRCA1, RAD51C/RAD51D/MMR mutations and the occasional families with a history of ovarian cancer in their 40s, surgery needs to be considered at younger than 45. In other moderate-risk gene mutation carriers and those with polygenic risk, RRSO needs be considered at 50. There is need for establishment/expansion of well-defined pathways to increase clinical access to RRSO. It is time to lower the risk threshold for RRSO to enable introduction of a targeted primary prevention approach, which could significantly impact the future burden of ovarian cancer.

Bernards SS, Pennington KP, Harrell MI, et al.
Clinical characteristics and outcomes of patients with BRCA1 or RAD51C methylated versus mutated ovarian carcinoma.
Gynecol Oncol. 2018; 148(2):281-285 [PubMed] Related Publications
OBJECTIVE: In ovarian carcinoma, mutations in homologous recombination DNA repair (HRR) genes, including BRCA1 and RAD51C, are associated with increased survival and specific clinical features. Promoter hypermethylation is another mechanism of reducing gene expression. We assessed whether BRCA1 and RAD51C promoter hypermethylation is associated with similar survival and clinical characteristics.
METHODS: Promoter methylation of BRCA1 and RAD51C was evaluated using methylation-sensitive PCR in 332 primary ovarian carcinomas. Damaging germline and somatic mutations in 16 HRR genes were identified using BROCA sequencing.
RESULTS: BRCA1 methylation was detected in 22 carcinomas (6.6%) and RAD51C methylation in 9 carcinomas (2.7%). These small numbers limited the power to detect differences in survival and platinum sensitivity. Mutations in one or more HRR genes were found in 95 carcinomas (29%). Methylation of BRCA1 or RAD51C was mutually exclusive with mutations in these genes (P=0.001). Patients whose carcinomas had BRCA1 methylation (57.7years±2.5) or BRCA1 mutations (54.1years±1.4) were younger than those without (63.3years±0.8; P=0.029, P<0.0001). BRCA1 methylation and germline BRCA1 mutation were associated with high grade serous (HGS) histology (P=0.045, P=0.001). BRCA1 mutations were associated with increased sensitivity to platinum chemotherapy while BRCA1 methylation was not (P=0.034, P=0.803). Unlike HRR mutations, methylation was not associated with improved overall survival compared to cases without methylation or mutation.
CONCLUSIONS: Patients with BRCA1-methylated carcinomas share clinical characteristics with patients with BRCA1-mutated carcinomas including younger age and predominantly HGS histology. However, unlike mutation, RAD51C and BRCA1 methylation were not associated with improved survival or greater sensitivity to platinum chemotherapy.

Jones MR, Kamara D, Karlan BY, et al.
Genetic epidemiology of ovarian cancer and prospects for polygenic risk prediction.
Gynecol Oncol. 2017; 147(3):705-713 [PubMed] Related Publications
Epithelial ovarian cancer (EOC) is a heterogeneous disease with a major heritable component. The different histotypes of invasive disease - high grade serous, clear cell, endometrioid and mucinous - are associated with different underlying genetic susceptibility and epidemiological and lifestyle risk factors, all of which contribute to the different biology and clinical characteristics of each histotype. A combination of familial and population based sequencing studies, and genome wide association studies (GWAS) have identified a range of genetic susceptibility alleles for EOC comprising rare but highly penetrant genes (e.g. BRCA1, BRCA2) that are responsible for familial clustering of ovarian cancer cases; more moderate penetrance susceptibility genes (e.g. BRIP1, RAD51C/D, MSH6); and multiple common but low penetrance susceptibility alleles identified by GWAS. Identifying genetic risk alleles for ovarian cancer has had a significant impact on disease prevention strategies; for example it is now routine clinical practice for individuals with germline BRCA1 and BRCA2 mutations to undergo risk reducing salpingo-oophorectomy. Because ovarian cancers are commonly diagnosed at a late clinical stage when the prognosis is poor, the continued development of genetic risk prediction and prevention strategies will represent an important approach to reduce mortality due to ovarian cancer. Advances in genomics technologies that enable more high-throughput genetic testing, combined with research studies that identify additional EOC risk alleles will likely provide further opportunities to establish polygenic risk prediction approaches, based on combinations of rare high/moderate penetrance susceptibility genes and common, low penetrance susceptibility alleles. This article reviews the current literature describing the genetic and epidemiological components of ovarian cancer risk, and discusses both the opportunities and challenges in using this information for clinical risk prediction and prevention.

Harter P, Hauke J, Heitz F, et al.
Prevalence of deleterious germline variants in risk genes including BRCA1/2 in consecutive ovarian cancer patients (AGO-TR-1).
PLoS One. 2017; 12(10):e0186043 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
BACKGROUND: Identification of families at risk for ovarian cancer offers the opportunity to consider prophylactic surgery thus reducing ovarian cancer mortality. So far, identification of potentially affected families in Germany was solely performed via family history and numbers of affected family members with breast or ovarian cancer. However, neither the prevalence of deleterious variants in BRCA1/2 in ovarian cancer in Germany nor the reliability of family history as trigger for genetic counselling has ever been evaluated.
METHODS: Prospective counseling and germline testing of consecutive patients with primary diagnosis or with platinum-sensitive relapse of an invasive epithelial ovarian cancer. Testing included 25 candidate and established risk genes. Among these 25 genes, 16 genes (ATM, BRCA1, BRCA2, CDH1, CHEK2, MLH1, MSH2, MSH6, NBN, PMS2, PTEN, PALB2, RAD51C, RAD51D, STK11, TP53) were defined as established cancer risk genes. A positive family history was defined as at least one relative with breast cancer or ovarian cancer or breast cancer in personal history.
RESULTS: In total, we analyzed 523 patients: 281 patients with primary diagnosis of ovarian cancer and 242 patients with relapsed disease. Median age at primary diagnosis was 58 years (range 16-93) and 406 patients (77.6%) had a high-grade serous ovarian cancer. In total, 27.9% of the patients showed at least one deleterious variant in all 25 investigated genes and 26.4% in the defined 16 risk genes. Deleterious variants were most prevalent in the BRCA1 (15.5%), BRCA2 (5.5%), RAD51C (2.5%) and PALB2 (1.1%) genes. The prevalence of deleterious variants did not differ significantly between patients at primary diagnosis and relapse. The prevalence of deleterious variants in BRCA1/2 (and in all 16 risk genes) in patients <60 years was 30.2% (33.2%) versus 10.6% (18.9%) in patients ≥60 years. Family history was positive in 43% of all patients. Patients with a positive family history had a prevalence of deleterious variants of 31.6% (36.0%) versus 11.4% (17.6%) and histologic subtype of high grade serous ovarian cancer versus other showed a prevalence of deleterious variants of 23.2% (29.1%) and 10.2% (14.8%), respectively. Testing only for BRCA1/2 would miss in our series more than 5% of the patients with a deleterious variant in established risk genes.
CONCLUSIONS: 26.4% of all patients harbor at least one deleterious variant in established risk genes. The threshold of 10% mutation rate which is accepted for reimbursement by health care providers in Germany was observed in all subgroups analyzed and neither age at primary diagnosis nor histo-type or family history sufficiently enough could identify a subgroup not eligible for genetic counselling and testing. Genetic testing should therefore be offered to every patient with invasive epithelial ovarian cancer and limiting testing to BRCA1/2 seems to be not sufficient.

Eoh KJ, Kim JE, Park HS, et al.
Detection of Germline Mutations in Patients with Epithelial Ovarian Cancer Using Multi-gene Panels: Beyond BRCA1/2.
Cancer Res Treat. 2018; 50(3):917-925 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
Purpose: Next-generation sequencing (NGS) allows simultaneous sequencing of multiple cancer susceptibility genes and may represent a more efficient and less expensive approach than sequential testing. We assessed the frequency of germline mutations in individuals with epithelial ovarian cancer (EOC), using multi-gene panels and NGS.
Materials and Methods: Patients with EOC (n=117) with/without a family history of breast or ovarian cancer were recruited consecutively, from March 2016 toDecember 2016.GermlineDNAwas sequenced using 35-gene NGS panel, in order to identify mutations. Upon the detection of a genetic alteration using the panel, results were cross-validated using direct sequencing.
Results: Thirty-eight patients (32.5%) had 39 pathogenic or likely pathogenic mutations in eight genes, including BRCA1 (n=21), BRCA2 (n=10), BRIP1 (n=1), CHEK2 (n=2), MSH2 (n=1), POLE (n=1), RAD51C (n=2), and RAD51D (n=2). Among 64 patients with a family history of cancer, 27 (42.2%) had 27 pathogenic or likely pathogenic mutations, and six (9.3%) had mutations in genes other than BRCA1/2, such as CHECK2, MSH2, POLE, and RAD51C. Fifty-five patients (47.0%) were identified to carry only variants of uncertain significance.
Conclusion: Using the multi-gene panel test, we found that, of all patients included in our study, 32.5% had germline cancer-predisposing mutations. NGS was confirmed to substantially improve the detection rates of a wide spectrum of mutations in EOC patients compared with those obtained with the BRCA1/2 testing alone.

Sung PL, Wen KC, Chen YJ, et al.
The frequency of cancer predisposition gene mutations in hereditary breast and ovarian cancer patients in Taiwan: From BRCA1/2 to multi-gene panels.
PLoS One. 2017; 12(9):e0185615 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
An important role of genetic factors in the development of breast cancer (BC) or ovarian cancer (OC) in Taiwanese (ethnic Chinese) patients has been suggested. However, other than germline BRCA1 or BRCA2 mutations, which are related to hereditary breast-ovarian cancer (HBOC), cancer-predisposition genes have not been well studied in this population. The aim of the present study was to more accurately summarize the prevalence of genetic mutations in HBOC patients using various gene panels ranging in size from BRCA1/2 alone to multi-gene panels. Among 272 HBOC patients analyzed, the prevalence of BRCA1, BRCA2 and non-BRCA1/2 pathogenic mutations was 7.7% (21/272), 6.8% (16/236) and 8.2% (13/159), respectively. The total mutation rate was 18.4% (50/272). Although no founder mutations were identified in this study, two recurrent mutations, BRCA1 (c.3607C>T) and BRCA2 (c.5164_5165 delAG), were found. The main pathogenic/likely pathogenic mutations in non-BRCA1/2 genes included ATM, BRIP1, FANCI, MSH2, MUYTH, RAD50, RAD51C and TP53. The prevalence rate of gene mutations in HBOC patients did not differ with respect to whether BC or OC was the first diagnosis or they presented a family history of the disease or their age at diagnosis. HBOC patients with both BC and OC exhibited a higher prevalence rate of mutations (50.0%) than patients with OC (25.0%) or BC (8.6%) alone. In conclusion, evaluation of hereditary cancer risk in Taiwan HBOC patients, particularly individuals with double cancer, is strongly encouraged. Panel testing can yield additional genomic information, and widespread and well-designed panel testing will help in assessing more accurate mutational prevalence of risk genes.

Wang X, Teer JK, Tousignant RN, et al.
Breast cancer risk and germline genomic profiling of women with neurofibromatosis type 1 who developed breast cancer.
Genes Chromosomes Cancer. 2018; 57(1):19-27 [PubMed] Related Publications
NF1 mutations predispose to neurofibromatosis type 1 (NF1) and women with NF1 have a moderately elevated risk for breast cancer, especially under age 50. Germline genomic analysis may better define the risk so screening and prevention can be applied to the individuals who benefit the most. Survey conducted in several neurofibromatosis clinics in the United States has demonstrated a 17.2% lifetime risk of breast cancer in women affected with NF1. Cumulated risk to age 50 is estimated to be 9.27%. For genomic profiling, fourteen women with NF1 and a history of breast cancer were recruited and underwent whole exome sequencing (WES), targeted genomic DNA based and RNA-based analysis of the NF1 gene. Deleterious NF1 pathogenic variants were identified in each woman. Frameshift mutations because of deletion/duplication/complex rearrangement were found in 50% (7/14) of the cases, nonsense mutations in 21% (3/14), in-frame splice mutations in 21% (3/14), and one case of missense mutation (7%, 1/14). No deleterious mutation was found in the following high/moderate-penetrance breast cancer genes: ATM, BRCA1, BRCA2, BARD1, BRIP1, CDH1, CHEK2, FANCC, MRE11A, NBN, PALB2, PTEN, RAD50, RAD51C, TP53, and STK11. Twenty-five rare or common variants in cancer related genes were discovered and may have contributed to the breast cancers in these individuals. Breast cancer predisposition modifiers in women with NF1 may involve a great variety of molecular and cellular functions.

Lilyquist J, LaDuca H, Polley E, et al.
Frequency of mutations in a large series of clinically ascertained ovarian cancer cases tested on multi-gene panels compared to reference controls.
Gynecol Oncol. 2017; 147(2):375-380 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
OBJECTIVES: Given the lack of adequate screening modalities, knowledge of ovarian cancer risks for carriers of pathogenic alterations in predisposition genes is important for decisions about risk-reduction by salpingo-oophorectomy. We sought to determine which genes assayed on multi-gene panels are associated with ovarian cancer, the magnitude of the associations, and for which clinically meaningful associations could be ruled out.
METHODS: 7768 adult ovarian cancer cases of European ancestry referred to a single clinical testing laboratory underwent multi-gene panel testing for detection of pathogenic alterations in known or suspected ovarian cancer susceptibility genes. A targeted capture approach was employed to assay each of 19 genes for the presence of pathogenic or likely pathogenic alterations. Mutation frequencies in ovarian cancer cases were compared to mutation frequencies in individuals from the Exome Aggregation Consortium (ExAC). Analyses stratified by family and personal history of other cancers and age at diagnosis were also performed.
RESULTS: Significant associations (p<0.001) were identified between alterations in 11 genes and ovarian cancer, with eight of these displaying ≥5-fold increased risk (BRCA1, BRCA2, BRIP1, MSH2, MSH6, RAD51C, RAD51D). Relative risks of ovarian cancer greater than two-fold were also observed for ATM, but could reliably be ruled out for RAD50 and CHEK2.
CONCLUSIONS: These results will inform clinical management of women found to carry pathogenic alterations in genes tested on multi-gene panels. The knowledge that some genes are not associated with OC can reduce concerns of women found to carry pathogenic alterations in those genes.

Hallamies S, Pelttari LM, Poikonen-Saksela P, et al.
CHEK2 c.1100delC mutation is associated with an increased risk for male breast cancer in Finnish patient population.
BMC Cancer. 2017; 17(1):620 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
BACKGROUND: Several susceptibility genes have been established for female breast cancer, of which mutations in BRCA1 and especially in BRCA2 are also known risk factors for male breast cancer (MBC). The role of other breast cancer genes in MBC is less well understood.
METHODS: In this study, we have genotyped 68 MBC patients for the known breast or ovarian cancer associated mutations in the Finnish population in CHEK2, PALB2, RAD51C, RAD51D, and FANCM genes.
RESULTS: CHEK2 c.1100delC mutation was found in 4 patients (5.9%), which is significantly more frequent than in the control population (OR: 4.47, 95% CI 1.51-13.18, p = 0.019). Four CHEK2 I157T variants were also detected, but the frequency did not significantly differ from population controls (p = 0.781). No RAD51C, RAD51D, PALB2, or FANCM mutations were found.
CONCLUSIONS: These data suggest that the CHEK2 c.1100delC mutation is associated with an increased risk for MBC in the Finnish population.

Ding YC, Adamson AW, Steele L, et al.
Discovery of mutations in homologous recombination genes in African-American women with breast cancer.
Fam Cancer. 2018; 17(2):187-195 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
African-American women are more likely to develop aggressive breast cancer at younger ages and experience poorer cancer prognoses than non-Hispanic Caucasians. Deficiency in repair of DNA by homologous recombination (HR) is associated with cancer development, suggesting that mutations in genes that affect this process may cause breast cancer. Inherited pathogenic mutations have been identified in genes involved in repairing DNA damage, but few studies have focused on African-Americans. We screened for germline mutations in seven HR repair pathway genes in DNA of 181 African-American women with breast cancer, evaluated the potential effects of identified missense variants using in silico prediction software, and functionally characterized a set of missense variants by yeast two-hybrid assays. We identified five likely-damaging variants, including two PALB2 truncating variants (Q151X and W1038X) and three novel missense variants (RAD51C C135R, and XRCC3 L297P and V337E) that abolish protein-protein interactions in yeast two-hybrid assays. Our results add to evidence that HR gene mutations account for a proportion of the genetic risk for developing breast cancer in African-Americans. Identifying additional mutations that diminish HR may provide a tool for better assessing breast cancer risk and improving approaches for targeted treatment.

Domchek SM
Reversion Mutations with Clinical Use of PARP Inhibitors: Many Genes, Many Versions.
Cancer Discov. 2017; 7(9):937-939 [PubMed] Related Publications
Reversion mutations associated with PARP inhibitor resistance have been identified in tumors with

Gayarre J, Martín-Gimeno P, Osorio A, et al.
Characterisation of the novel deleterious RAD51C p.Arg312Trp variant and prioritisation criteria for functional analysis of RAD51C missense changes.
Br J Cancer. 2017; 117(7):1048-1062 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
BACKGROUND: Despite a high prevalence of deleterious missense variants, most studies of RAD51C ovarian cancer susceptibility gene only provide in silico pathogenicity predictions of missense changes. We identified a novel deleterious RAD51C missense variant (p.Arg312Trp) in a high-risk family, and propose a criteria to prioritise RAD51C missense changes qualifying for functional analysis.
METHODS: To evaluate pathogenicity of p.Arg312Trp variant we used sequence homology, loss of heterozygosity (LOH) and segregation analysis, and a comprehensive functional characterisation. To define a functional-analysis prioritisation criteria, we used outputs for the known functionally confirmed deleterious and benign RAD51C missense changes from nine pathogenicity prediction algorithms.
RESULTS: The p.Arg312Trp variant failed to correct mitomycin and olaparib hypersensitivity and to complement abnormal RAD51C foci formation according to functional assays, which altogether with LOH and segregation data demonstrated deleteriousness. Prioritisation criteria were based on the number of predictors providing a deleterious output, with a minimum of 5 to qualify for testing and a PredictProtein score greater than 33 to assign high-priority indication.
CONCLUSIONS: Our study points to a non-negligible number of RAD51C missense variants likely to impair protein function, provides a guideline to prioritise and encourage their selection for functional analysis and anticipates that reference laboratories should have available resources to conduct such assays.

Polak P, Kim J, Braunstein LZ, et al.
A mutational signature reveals alterations underlying deficient homologous recombination repair in breast cancer.
Nat Genet. 2017; 49(10):1476-1486 [PubMed] Related Publications
Biallelic inactivation of BRCA1 or BRCA2 is associated with a pattern of genome-wide mutations known as signature 3. By analyzing ∼1,000 breast cancer samples, we confirmed this association and established that germline nonsense and frameshift variants in PALB2, but not in ATM or CHEK2, can also give rise to the same signature. We were able to accurately classify missense BRCA1 or BRCA2 variants known to impair homologous recombination (HR) on the basis of this signature. Finally, we show that epigenetic silencing of RAD51C and BRCA1 by promoter methylation is strongly associated with signature 3 and, in our data set, was highly enriched in basal-like breast cancers in young individuals of African descent.

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