Hereditary Breast And Ovarian Cancer Patients Research Articles

Abstract PO4-15-02: ApoE polymorphism is associated with aggressive tumor phenotypes for breast cancer patients

Abstract Introduction: Apolipoprotein E (APOE) is implicated in several biological processes, such as protein synthesis, cell growth and differentiation, cholesterol transport, lipid metabolism, and tissue repair. APOE has different isoforms (E2, E3, and E4) that combine conflicting relations with cancer risk. This study aimed to evaluate the distribution of different isoforms of APOE among suspected HBOC (Hereditary Breast and Ovarian Cancer Syndrome) patients. Methodology: DNA was extracted from the blood cells of 108 patients. The detection was performed using qPCR after amplifying specific regions containing the polymorphisms. It was considered that all the amplicons containing Cq amplification < 35. The melting curve for each patient was analyzed to determine the frequency of the isoforms E2, E3, E4, and genotypes E2/E2, E2/E3, E2E4, E3/E3, and E3/E4. The allele and genotype were also correlated with hereditary variants previously identified by genetic tests for germline mutations and with tumoral phenotype. The data were expressed in frequency and associated using chi-square tests or Fisher's exact test (SPSS v20.0, p< 0.05). Results A total of 108 patients filling criteria for HBOC syndrome were evaluated. Among them, 15 (13.9%) had a mutation in BRCA1, 5 (4.6%) in BRCA2, and 2 (1.9%) in TP53. Most patients were under 45 years old (n=76, 70.4%), female (n=104, 96.3%), had a high school education (n=44, 44.0%), were non-smokers (n=79, 80.6%) or drinkers (n=76, 78.4%), and had no comorbidities (n=66, 64.1%). Overweight at diagnosis was observed in 61 (68.5%) individuals. The most frequent tumor phenotype and stage were luminal B (n=46, 43.4%) and stage IIIA (n=22, 26.2%), respectively. Neoadjuvant chemotherapy was performed in 40 (47.1%) with a high rate of complete and partial response 18 (36.7%) and 22 (44.9%), respectively. Regarding ApoE polymorphisms, the E2 allele showed the lowest frequency (n=7, 6.5%), E3 was present in 103 (95.4%) cases, while E4 was present in 39 (36.1%). The most frequent genotype was E3/E3 (n=64, 58.3%), followed by E3/E4 (n=34, 31.5%), E2/E3 (n=6, 5.6%), E4 (n=4, 3.7%), and E2/E4 (n=1, 0.9%). No cases of E2/E2 genotype were observed. The presence of E2 was inversely associated with comorbidity frequency (p=0.040) but directly associated with TP53 mutation (p=0.012) and triple-negative tumor phenotype (p=0.027). E3 was not associated with clinical characteristics, but E4 was associated with low Ki-67 immunoreactivity (p=0.033). The E2/E3 phenotype was directly associated with triple-negative tumors (p=0.044) and heterozygous tumors (p=0.011). Conclusion: The ApoE polymorphism, particularly the presence of the E2 allele in heterozygosity, is associated with TP53 mutation and a more aggressive tumor phenotype. Citation Format: Maria Claudia Luciano, Rosane Sant' Ana, Valeska Lima, Paulo Goberlanio Silva, Clarissa Albuquerquye, Flavio Bitencourt, Maria Julia Bezerra, Francisca Fernanda Oliveira, José Fernando De Moura, Isabelle Joyce Fernandes, Fernanda Leite. ApoE polymorphism is associated with aggressive tumor phenotypes for breast cancer patients [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-15-02.

Brca2(p.T1942fs/+) dissipates ovarian reserve in rats through oxidative stress in follicular granulosa cells

Pathogenic variants of BRCA1/2 constitute hereditary breast and ovarian cancer (HBOC) syndrome, and BRCA1/2 mutant is a risk for various cancers. Whereas the clinical guideline for HBOC patients has been organized for the therapy and prevention of cancer, there is no recommendation on the female reproductive discipline. Indeed, the role of BRCA1/2 pathogenic variants in ovarian reserve has not been established due to the deficiency of appropriate animal models. Here, we used a rat model of Brca2(p.T1942fs/+) mutant of Sprague-Dawley strain with CRISPR-Cas9 editing to evaluate ovarian reserve in females. Fertility and ovarian follicles were evaluated and anti-Müllerian hormone (AMH) was measured at 8–32 weeks of age with a comparison between the wild-type and the mutant rats (MUT). MUT revealed a significantly smaller number of deliveries with fewer total pups. Furthermore, MUT showed a significant decrease in primordial follicles at 20 weeks and a low AMH level at 28 weeks. RNA-sequencing of the ovary at 10 weeks detected acceleration of the DNA damage repair pathway, which was accompanied by oxidative stress-induced DNA double-strand breaks, a decrease in PTEN, and an increase in mTOR in follicular granulosa cells. In conclusion, Brca2(p.T1942fs/+) dissipates primordial follicles via early activation of granulosa cells through oxidative stress, leading to earlier termination of fertility.

Risk-reducing decisions regarding germline BRCA pathogenic variant: focusing on the timing of genetic testing and RRSO

BackgroundIn Japan, the public insurance policy was revised in 2020 to cover hereditary breast and ovarian cancer (HBOC), including genetic testing and surveillance, for patients with breast cancer (BC). Consequently,...

Co-Occurrence of Germline Genomic Variants and Copy Number Variations in Hereditary Breast and Colorectal Cancer Patients.

Hereditary Breast and Ovarian Cancer (HBOC) syndrome is an autosomal dominant disease associated with a high risk of developing breast, ovarian, and other malignancies. Lynch syndrome is caused by mutations in mismatch repair genes predisposing to colorectal and endometrial cancers, among others. A rare phenotype overlapping hereditary colorectal and breast cancer syndromes is poorly characterized. Three breast and colorectal cancer unrelated patients fulfilling clinical criteria for HBOC were tested by whole exome sequencing. A family history of colorectal cancer was reported in two patients (cases 2 and 3). Several variants and copy number variations were identified, which potentially contribute to the cancer risk or prognosis. All patients presented copy number imbalances encompassing PMS2 (two deletions and one duplication), a known gene involved in the DNA mismatch repair pathway. Two patients showed gains covering the POLE2 (cases 1 and 3), which is associated with DNA replication. Germline potentially damaging variants were found in PTCH1 (patient 3), MAT1A, and WRN (patient 2). Overall, concurrent genomic alterations were described that may increase the risk of cancer appearance in HBOC patients with breast and colorectal cancers.

Abstract 5768: Genetic screening in a tertiary medical center identifies carriers of cancer predisposition diseases that would be missed by clinical guidelines

Abstract Two inherited autosomal dominant cancer predisposition conditions - BRCA related hereditary breast and ovarian cancer (HBOC) and Lynch syndrome (LS) - are termed Centers for Disease Control and Prevention Tier 1 (CDCT1) genetic conditions, for which early identification and intervention have a positive impact on public health. Selection of individuals for genetic testing for these conditions is based on personal and family history. The goal of this study was to evaluate whether screening in a tertiary medical center using exome sequencing could efficiently identify carriers of HBOC and LS and to determine the frequency of incremental carriers identified outside of traditional clinical practice guidelines. Participants from three geographically diverse Mayo Clinic practices in the USA (Rochester MN, Phoenix AZ, Jacksonville FL) consented to clinical “Exome+” sequencing (Helix, San Mateo, CA; Mayo GeneGuide, Rochester, MN) in the TAPESTRY study (NCT05212428), which links sequencing data with electronic health records and the return of CDCT1 genetic findings. For this study we focused on two inherited cancer predisposition conditions: BRCA-related HBOC (BRCA1 and BRCA2) and LS (MLH1, MSH2, MSH6, PMS2 and EPCAM). Detailed chart review to collect demographic information, personal and family history, and assessment of clinical practice guidelines for genetic evaluation (National Cancer Control Network 2021). To date, 44,306 patients have enrolled and sequenced in TAPESTRY. Annotation and interpretation of all variants in 7 genes for HBOC and LS resulted in identification of 550 carriers (prevalence 1.24%) which included 387 with HBOC (27.2% BRCA1, 42.8% BRCA2) and 163 with LS (12.3% MSH6, 8.8% PMS2, 4.5% MLH1, 3.8% MSH2 and 0.2% EPCAM). Demographics of the cohort included: 62.7% female, mean age 55.2 years, non-white race 9.6% and 3.8% Hispanic/Latino ethnicity. A personal history of cancer was present in 46.4% of test positive patients, including 22.5% of HBOC patients with breast or ovarian cancer and 20.9% of LS patients with colorectal or uterine cancer. More than half of the patients (52.1%) were newly diagnosed with HBOC and LS based on the results of this study. Overall, 39.2% of HBOC/LS carriers identified through Exome+ sequencing did not satisfy NCCN criteria for genetic evaluation, this was higher for LS (56.2%) compared to HBOC (32%). Amongst those newly diagnosed with HBOC/LS (n=286), NCCN criteria were not satisfied in 60% of cases (78% for LS and 51% for HBOC). Of the pathogenic germline variant carriers who met NCCN guidelines for testing, 34.2% were not aware of their diagnosis prior to participation in this study. Our results emphasize the need for wide genomic screening for CDCT1 cancer predisposition syndromes. Such screening could identify at-risk carriers of HBOC and LS, who would not otherwise be identified through clinical practice guidelines. Citation Format: Emily Gay, Niloy Jewel Samadder, Michelle L. Bublitz, Melanie M. Peterson, Tammy A. Wilson, Lorelei A. Bandel, Sebastian M. Armasu, Robert A. Vierkant, Matthew J. Ferber, Eric W. Klee, Nicholas B. Larson, Teresa M. Kruisselbrink, Timothy B. Curry, Jan B. Egan, Jennifer L. Kemppainen, Jessa S. Bidwell, Jennifer L. Anderson, Tammy M. McAllister, T'Nita S. Walker, Katie L. Kunze, Vanda Lindpere, Michael A. Golafshar, Margaret Klint, Richard J. Presutti, William V. Bobo, Aleksander Sekulic, Jolene M. Summer Bolster, Cheryl L. Willman, Konstantinos N. Lazaridis. Genetic screening in a tertiary medical center identifies carriers of cancer predisposition diseases that would be missed by clinical guidelines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5768.

Diagnostic yield and clinical relevance of expanded germline genetic testing for nearly 7000 suspected HBOC patients

Here we report the results of a retrospective germline analysis of 6941 individuals fulfilling the criteria necessary for genetic testing of hereditary breast- and ovarian cancer (HBOC) according to the German S3 or AGO Guidelines. Genetic testing was performed by next-generation sequencing using 123 cancer-associated genes based on the Illumina TruSight® Cancer Sequencing Panel. In 1431 of 6941 cases (20.6%) at least one variant was reported (ACMG/AMP classes 3–5). Of those 56.3% (n = 806) were class 4 or 5 and 43.7% (n = 625) were a class 3 (VUS). We defined a 14 gene HBOC core gene panel and compared this to a national and different internationally recommended gene panels (German Hereditary Breast and Ovarian Cancer Consortium HBOC Consortium, ClinGen expert Panel, Genomics England PanelsApp) in regard of diagnostic yield, revealing a diagnostic range of pathogenic variants (class 4/5) from 7.8 to 11.6% depending on the panel evaluated. With the 14 HBOC core gene panel having a diagnostic yield of pathogenic variants (class 4/5) of 10.8%. Additionally, 66 (1%) pathogenic variants (ACMG/AMP class 4 or 5) were found in genes outside the 14 HBOC core gene set (secondary findings) that would have been missed with the restriction to the analysis of HBOC genes. Furthermore, we evaluated a workflow for a periodic re-evaluation of variants of uncertain clinical significance (VUS) for the improvement of clinical validity of germline genetic testing.

Lack of impact of the ALDH2 rs671 variant on breast cancer development in Japanese BRCA1/2-mutation carriers.

The aldehyde degrading function of the ALDH2 enzyme is impaired by Glu504Lys polymorphisms (rs671, termed A allele), which causes alcohol flushing in east Asians, and elevates the risk of esophageal cancer among habitual drinkers. Recent studies suggested that the ALDH2 variant may lead to higher levels of DNA damage caused by endogenously generated aldehydes. This can be a threat to genome stability and/or cell viability in a synthetic manner in DNA repair-defective settings such as Fanconi anemia (FA). FA is an inherited bone marrow failure syndrome caused by defects in any one of so far identified 22 FANC genes including hereditary breast and ovarian cancer (HBOC) genes BRCA1 and BRCA2. We have previously reported that the progression of FA phenotypes is accelerated with the ALDH2 rs671 genotype. Individuals with HBOC are heterozygously mutated in either BRCA1 or BRCA2, and the cancer-initiating cells in these patients usually undergo loss of the wild-type BRCA1/2 allele, leading to homologous recombination defects. Therefore, we hypothesized that the ALDH2 genotypes may impact breast cancer development in BRCA1/2 mutant carriers. We genotyped ALDH2 in 103 HBOC patients recruited from multiple cancer centers in Japan. However, we were not able to detect any significant differences in clinical stages, histopathological classification, or age at clinical diagnosis across the ALDH2 genotypes. Unlike the effects in hematopoietic cells of FA, our current data suggest that there is no impact of the loss of ALDH2 function in cancer initiation and development in breast epithelium of HBOC patients.

Detection of BRCA1/2 pathogenic variants in patients with breast and/or ovarian cancer and their families. Analysis of 3,458 cases from Lower Silesia (Poland) according to the diagnostic algorithm of the National Cancer Control Programme.

Breast and ovarian cancers are among the most common malignancies in the female population, with approximately 5–10% of cases being hereditary. BRCA1 and BRCA2 with other homologous recombination genes are the most tested genes in hereditary breast and ovarian cancer (HBOC) patients. As next-generation sequencing (NGS) has become a standard and popular technique, such as for HBOC, it has greatly simplified and accelerated molecular diagnosis of cancer. The study group included 3,458 HBOC patients or their relatives from Lower Silesia (Poland) (a voivodeship located in south-west Poland inhabited by 2.9 million people). All patients were tested according to the recommendations from the National Cancer Control Programme of the Ministry of Health for the years 2018–21. We tested 3,400 patients for recurrent pathogenic variants for the Polish population: five BRCA1 founder variants (c.5266dup, c.181T>G, c.4035del, c.3700_3704del, and c.68_69del), two PALB2 variants (c.509_510del, c.172_175del) and three CHEK2 variants [c.1100del, c.444+1G>A, g.27417113-27422508del (del5395)]. Next 260 patients from the study group were chosen for the BRCA1/2 NGS panel, and additionally selected marker pathogenic variants were tested using Sanger sequencing and MLPA methods in 45 and 13 individuals, respectively. The analysis of BRCA1/2 in the 3,458 patients with HBOC or their relatives revealed 144 carriers of 37 different pathogenic variants (22 in BRCA1 and 15 in BRCA2). Among all detected variants, 71.53% constituted founder pathogenic BRCA1 variants. Our study has revealed that for the Lower Silesian population, the first-line BRCA1/2 molecular test may be limited to only three variants in BRCA1—c.5266dup, c.181T>G, and c.4035del—but the aim should be to provide a full screening test of HBOC critical genes. The key and still growing role of molecular diagnostics of neoplasms, which includes HBOC, is undeniable. Therefore, it is necessary to provide complete and optimal therapeutic and prophylactic algorithms in line with current medical knowledge.

Functions of Breast Cancer Predisposition Genes: Implications for Clinical Management.

Approximately 5–10% of all breast cancer (BC) cases are caused by germline pathogenic variants (GPVs) in various cancer predisposition genes (CPGs). The most common contributors to hereditary BC are BRCA1 and BRCA2, which are associated with hereditary breast and ovarian cancer (HBOC). ATM, BARD1, CHEK2, PALB2, RAD51C, and RAD51D have also been recognized as CPGs with a high to moderate risk of BC. Primary and secondary cancer prevention strategies have been established for HBOC patients; however, optimal preventive strategies for most hereditary BCs have not yet been established. Most BC-associated CPGs participate in DNA damage repair pathways and cell cycle checkpoint mechanisms, and function jointly in such cascades; therefore, a fundamental understanding of the disease drivers in such cascades can facilitate the accurate estimation of the genetic risk of developing BC and the selection of appropriate preventive and therapeutic strategies to manage hereditary BCs. Herein, we review the functions of key BC-associated CPGs and strategies for the clinical management in individuals harboring the GPVs of such genes.

Disparate cancer risk reduction among hereditary breast and ovarian cancer syndrome patients at an urban hospital center

<h3>Objectives:</h3> Risk reducing surgery remains the most effective strategy to reduce the risk of ovarian cancer in women with a Hereditary Breast and Ovarian Cancer (HBOC) syndrome. Despite the substantial survival benefit, women often do not undergo risk reducing bilateral salpingo-oophorectomy (RRBSO) within the NCCN-recommended timeframes. The aim of this study was to examine factors impacting the timing and surgical uptake of RRBSO in high-risk patients receiving care at our academic urban health care system. <h3>Methods:</h3> Patients who underwent RRBSO between January 1, 2017 and September 1, 2020 at our health care system were identified using ICD codes. Demographic information collected included age, race, mutation type, personal history of cancer, family history of cancer, and type of insurance. Dates of initial gynecologic presentation, genetic testing, and surgery were recorded. Descriptive statistics were completed using SPSS 2.0 software and multiple linear regression modeling was performed to assess factors impacting timing to RRBSO. <h3>Results:</h3> One hundred sixty seven patients underwent gynecologic RRBSO during the study period. The median age of patients at time of RRBSO was 47 years (range 30-74), 134 (80.5%) identified as White, 155 (92.8%) as non-Hispanic, 159 (95.2%) spoke English as their primary language, 135 (80.8%) had private insurance. 62 (37.1%) had a <i>BRCA1</i> mutation, 69 (41.3%) a <i>BRCA2</i> mutation, and 17 (10.1%) another HBOC-related mutation. 61 (36.4%) had a personal history of cancer while 19 (11.5%) had a family history of cancer. Of the 167 patients who underwent RRBSO, 5 (2.9%) had a serous tubal intraepithelial carcinoma precursor lesion or occult invasive cancer diagnosed at time of surgery.Privately insured patients underwent RRBSO at a median age of 40 (range 28-74) whereas publicly insured patient were 46 (range 23-69) (p=0.849). The median age for genetic testing was 40 years (range 28-74) in privately insured patients and 46 years (range 23-69) in publicly insured (p=0.849). The median time from genetic testing to surgery was 51 weeks (range 3-650). On multivariate analysis, age (p<0.001) and insurance status (p=0.045) significantly impacted time from genetic testing to surgery. Patients above the age of 50 were more likely to get RRBSO in a quicker timeframe from genetic testing than patients under the age of 50 (P<0.001). <h3>Conclusions:</h3> In our cohort, publicly insured HBOC patients underwent genetic testing and RRBSO at a later median age compared to privately insured patients. While this difference was not statistically significant, it suggests a socioeconomic disparity in the age at which genetic testing and RRBSO are being completed, with RRBSOs falling outside the age recommendation of guideline-directed care. Optimizing implementation of genetic testing and RRBSO among publicly insured HBOC patients could lead to earlier identification of those at increased risk and a better opportunity to reduce the risk of cancer.

Abstract 887: Clinicopathological and genetic features of breast cancer in Algerian population: A multicenter study

Abstract Background: Breast cancer is the most commonly diagnosed cancer and the leading cause of morbidity and mortality among Algerian women.The objective of this retrospective cohort study was to analyze some clinicopathological and molecular characteristics of breast cancer diagnosed between 2011 and 2019. Here we also report the experience of our research laboratory for the screening of BRCA1 and BRCA2 genes in hereditary breast and ovarian cancer (HBOC) patients. Materials and Methods: The population study included 7655 consecutive breast cancer patients. Data were collected from cancer registries of three medical oncology services and two anti-cancer centers located in north central region and eastern region of Algeria, respectively. Breast cancers were diagnosed between 2011 and 2019. Patient and tumor information included: age at diagnosis, menopausal status, receptor status, Ki-67 score, histological type,TNM stage and histological grade. Recurrent germline mutations on BRCA1 and BRCA2 genes previously found in Algerian patients were screened using PCR-Sanger sequencing in 230 HBOC patients. In addition, 18 HBOC patients were analyzed by NGS using a cancer panel of 30 hereditary cancer genes or BRCA1/2 genetic test. Results: The median age at diagnosis of the patients was 49.52 years. Data for age at diagnosis were available for 7389 patients. 55.29% patients were diagnosed under the age of 50 years and 55.83% had a premenopausal status. Data for receptor status were available for a total of 5599 patients. Of these, 55.75% patients were luminal A, 19.79% were TNBC, 17.39% were luminal B and 7.05% were HER2+. Data for Ki-67 score were available for 3357 cases. We noticed that 62.73% patients had a Ki-67 score ≥ 20% and 37.27% had a score &amp;lt;20%. Data for histological tumor type were available for 6145 cases. 84.28% patients had invasive ductal carcinoma followed by 8.84% with invasive lobular carcinoma. Data for TNM stage were available for 3524 cases. We identified 59.3% patients with stage III, 22.3% with stage II and 9.5% with stage IV. Data for histological grade were available for 6693 patients. We found 67.45% patients with grade II and 25.51% with grade III, respectively. 10 distinct BRCA1 germline mutations have been detected in 18 families and 5 distinct BRCA2 germline mutations have been identified in 5 families. The BRCA1 recurrent mutation c.83_84delTG has been detected in 5 unrelated families.The BRCA1 recurrent mutation c.2125_2126insA has been identified in 3 unrelated families. In addition, the BRCA1 c.181T&amp;gt;G has been found in two unrelated families. Interestingly, our results also showed differences in the distribution of the mutation spectrum of BRCA1 and BRCA2 genes between the eastern region and the north central region of Algeria. Conclusion: Our current study will contribute in developing optimal clinical trial protocols and personalized management strategies for breast cancer patients. Citation Format: Farid Cherbal, Leticia Ledmila Saada, Massila Nehar, Kamelia Yatta, Lydia Souha Zerrouki, Wafa Abdou, Chiraz Mehemmai, Hadjer Gaceb, Wassila Benbrahim, Hassen Mahfouf, Kada Boualga. Clinicopathological and genetic features of breast cancer in Algerian population: A multicenter study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 887.

Genetic and clinical characterization of multigene hereditary breast and ovarian cancer (HBOC) panels in Málaga (Spain).

e22530 Background: Next Generation Sequencing (NGS) technologies have transformed hereditary breast and ovarian cancer (HBOC) testing process. Several multigene panels (MP) include from 10 to 100 candidate cancer susceptibility genes, but there is a debate about what genes should and should not be tested because of lack of actionability. Few studies have been reported about MP in Europe or Spanish cancer families and no studies in Andalusian population (southern Spain). Methods: We investigated a panel of 17 known genes of high/moderate-risk for HBOC in 938 clinically suspicious HBOC Andalusian families (SEOM 2015 criteria), tested from 2017 to 2019. Multigene panel including BRCA,1 BRCA2, CHEK2, PALB2, BRIP1, ATM, MLH1, MSH2, MSH6, PMS2, CDH1, NF1, PTEN, p53, STK11, RAD51C and RAD51D was performed. Results: We identified 130 patients who carried a high- or moderate-risk pathogenic variants: 61 in BRCA2 (47%), 30 in BRCA 1 (23%), 10 in CHEK2 (8%), 7 in ATM (5%), 7 in PALB2 (5%), 4 in RAD51 (3%), 4 in BRIP1 (3%), 4 in MSH6 (3%), 2 in MLH1 (1,5%) and 1 in MSH2. We detected 220 patients carry variants of uncertain significance (VUS), with a total of 248 VUS (some patients carried more than one VUS): 46 (19%) in ATM, 38 (15%) in BRCA 2, 28 (11%) in MSH6, 19 (8%) in PMS2, 17 (7%) in BRIP1, 16 (6%) in NF1, 14 (6%) in MSH2 and 12 (5%) in CDH1 and PALB2. The most frequent criteria in the entire cohort was “High-grade epithelial non-mucinous ovarian cancer”, reported in 243 cases (26%)”, whereas “Breast cancer (BC) diagnostic under 35” was the most frequent criteria between positives (48 cases (40%)). One case carried two pathogenic variants: BRCA2 and MUTYH. Conclusions: This is the first study reporting the mutational profile of MP gene testing in Andalusia. 70% of mutations were due to BRCA1 and 2 followed by far by CHEK2, ATM and PALB2. We also identified a large amount of VUS in BRCA2, ATM and MSH6. MP improve the diagnostic in andalusian HBOC patients.

Germline mutational spectrum in Armenian breast cancer patients suspected of hereditary breast and ovarian cancer

Hereditary breast and ovarian cancer (HBOC) can be identified by genetic testing of cancer-causing genes. In this study, we identified a spectrum of genetic variations among 76 individuals of Armenian descent either with a family history of cancer or breast cancer before the age of 40. We screened 76 suspected HBOC patients and family members as well as four healthy controls using a targeted and hereditary comprehensive cancer panel (127 genes). We found 26 pathogenic (path) and 6 likely pathogenic (LPath)variants in 6 genes in 44 patients (58%); these variants were found in BRCA1 (17), BRCA2 (19), CHEK2 (4), PALB2 (2), and NBN (1). A few different variants were found in unrelated individuals; most notably, variant p.Trp1815Ter in the BRCA1 gene occurred in four unrelated patients. We did not find any known significant variants in five patients. Comprehensive cancer panel testing revealed pathogenic variants in cancer genes other than BRCA1 and BRCA2, suggesting that testing only BRCA1 and BRCA2 would have missed 8 out of 44 suspected HBOC patients (18%). These data also confirm that a comprehensive cancer panel testing approach could be an appropriate way to identify most of the variants associated with hereditary breast cancer.

Investigating the causal role of MRE11A p.E506* in breast and ovarian cancer

The nuclease MRE11A is often included in genetic test panels for hereditary breast and ovarian cancer (HBOC) due to its BRCA1-related molecular function in the DNA repair pathway. However, whether MRE11A is a true predisposition gene for HBOC is still questionable. We determined to investigate this notion by dissecting the molecular genetics of the c.1516G > T;p.E506* truncating MRE11A variant, that we pinpointed in two unrelated French-Canadian (FC) HBOC patients. We performed a case–control study for the variant in ~ 2500 breast, ovarian, and endometrial cancer patients from the founder FC population of Quebec. Furthermore, we looked for the presence of second somatic alterations in the MRE11A gene in the tumors of the carriers. In summary, these investigations suggested that the identified variant is not associated with an increased risk of developing breast or ovarian cancer. We finally performed a systematic review for all the previously reported MRE11A variants in breast and ovarian cancer. We found that MRE11A germline variants annotated as pathogenic on ClinVar often lacked evidence for such classification, hence misleading the clinical management for affected patients. In summary, our report suggests the lack of clinical utility of MRE11A testing in HBOC, at least in the White/Caucasian populations.

Pathology of Hereditary Breast and Ovarian Cancer.

Hereditary breast and ovarian cancer (HBOC) syndrome is most commonly characterized by deleterious germline mutations in BRCA1 and BRCA2. HBOC patients are prone to the development of malignant neoplasms in multiple organs including the breast, ovary, and fallopian tube. From a pathological perspective, a number of morphological features have been described in BRCA-associated breast and tubo-ovarian cancers. For example, breast cancers diagnosed in BRCA1-mutation carriers are frequently of a high Nottingham grade and display medullary morphology and a triple-negative and/or a basal-like immunophenotype. In contrast, breast cancers in BRCA2-mutation carriers are similar to sporadic luminal-type tumors that are positive for hormone receptors and lack expression of human epidermal growth factor receptor 2. Cancers arising in the fallopian tube and ovary are almost exclusively of a high-grade serous histotype with frequent Solid, pseudo-Endometrioid, and Transitional cell carcinoma-like morphology (“SET features”), marked nuclear atypia, high mitotic index, abundant tumor infiltrating lymphocytes, and necrosis. In addition, pushing or infiltrative micropapillary patterns of invasion have been described in BRCA-associated metastases of tubo-ovarian high-grade serous carcinomas. Besides BRCA1 and BRCA2 mutations, alterations in a number of other homologous recombination genes with moderate penetrance, including PALB2, RAD51C, RAD51D, BRIP1, and others, have also been described in HBOC patients with varying frequency; however, distinct morphological characteristics of these tumors have not been well characterized to date. In this review, the above pathological features are discussed in detail and a focus is placed on how accurate pathologic interpretation plays an important role in allowing HBOC patients to receive the best possible management.

Prevalence of pathogenic non-BRCA1/2 gene variants in patients with suspected hereditary breast and ovarian cancer at a referral hospital in northeastern Brazil.

e13602 Background: Breast cancer (BC) is associated with several hereditary syndromes (HS). Patients with clinical criteria for hereditary breast and ovarian cancer (HBOC) should be evaluated for the presence of pathogenic BRCA1/2 variants, although the absence of BRCA1/2 variants does not rule out HS. The purpose of this study was to evaluate the prevalence of pathogenic non- BRCA1/2 variants in patients with suspected HBOC. Methods: Suspected HBOC (NCCN criteria) patients (n = 267) from a Northeastern Brazilian referral cancer hospital were submitted to NGS 31-gene painel. Individuals testing negative for BRCA1/2 mutation (n = 210) remained in the present presentation. Data were analized by the chi-squared test and Fisher’s test ( p&lt; 0.05; SPSS 20.0). Results: Pathogenic/likely pathogenic (P/LP) non- BRCA1/2 variants were detected in 13.3% (n = 28/210) of the patients, all of whom had BC. The most prevalent variant was PALB2 (31%), followed by ATM and MUTYH (14.2%), and TP53 and PMS2 (10.7%). Among these patients 10.7% (n = 3/28) had triple negative tumors. Other gene variants ( BARD1, CHEK2, MLH1, MSH2, PMS1 and XRCC2) were observed at lower frequencies (3.5% each). DNA mismatch repair (MMR)/Lynch syndrome (LS) mutated genes were identified in 4/24 patients with BC. Rare microdeletions were identified in PALB2 (chr16:23652431-23652678 [exons 1-10] and TP53 (chr17:7.573.927-7.579.891 [exons 2-10]) , to our knowledge for the first time in the medical literature (ClinVar). In addition, one patient displayed a double pathogenic variant in ATM (c.67C &gt; T: p.[Arg23*]) and PALB2 (chr16:23652431-23652678 [exons 1-10]). Patients with and without P/LP did not differ with regard to clinical-pathological parameters or therapeutic profile. Conclusions: Patients with suspected HBOC should be evaluated for non- BRCA1/2 variants, including MMR. We also suggest considering BC among the malignancies associated with LS.

Genetic Variants in the 3'UTR of BRCA1 and BRCA2 Genes and their Putative Effects on the microRNA Mechanism in Hereditary Breast and Ovarian Cancer.

Hereditary breast and ovarian cancer (HBOC) syndrome is mainly caused by mutations in the BRCA1 and BRCA2 genes. The 3’UTR region allows for the binding of microRNAs, which are involved in genetic tune regulation. We aimed to identify allelic variants on 3’UTR miRNA-binding sites in the BRCA1 and BRCA2 genes in HBOC patients. Blood samples were obtained from 50 patients with HBOC and from 50 controls. The 3’UTR regions of BRCA1 and BRCA2 were amplified by PCR and sequenced to identify genetic variants using bioinformatics tools. We detected nine polymorphisms in 3’UTR, namely: four in BRCA1 (rs3092995 (C/G), rs8176318 (C/T), rs111791349 (G/A), and rs12516 (C/T)) and five in BRCA2 (rs15869 (A/C), rs7334543 (A/G), rs1157836 (A/G), and rs75353978 (TT/del TT)). A new variant in position c.*457 (A/C) on 3’UTR of BRCA2 was also identified. The following three variants increased the risk of HBOC in the study population: rs111791349-A, rs15869-C, and c.*457-C (odds ratio (OR) range 3.7–15.4; p < 0.05). Genetic variants into the 3’UTR of BRCA1 and BRCA2 increased the risk of HBOC between 3.7–15.4 times in the study population. The presence/absence of these polymorphisms may influence the loss/creation of miRNA binding sites, such as hsa-miR-1248 in BRCA1 3′UTR or the hsa-miR-548 family binding site in BRCA2. Our results add new evidence of miRNA participation in the pathogenesis of HBOC.

Exome Sequencing in BRCA1- and BRCA2-Negative Greek Families Identifies MDM1 and NBEAL1 as Candidate Risk Genes for Hereditary Breast Cancer.

Approximately 10% of breast cancer (BC) cases are hereditary BC (HBC), with HBC most commonly encountered in the context of hereditary breast and ovarian cancer (HBOC) syndrome. Although thousands of loss-of-function (LoF) alleles in over 20 genes have been associated with HBC susceptibility, the genetic etiology of approximately 50% of cases remains unexplained, even when polygenic risk models are considered. We focused on one of the least-studied European populations and applied whole-exome sequencing (WES) to 52 individuals from 17 Greek HBOC families, in which at least one patient was negative for known HBC risk variants. Initial screening revealed pathogenic variants in known cancer genes, including BARD1:p.Trp91* detected in a cancer-free individual, and MEN1:p.Glu260Lys detected in a BC patient. Gene- and variant-based approaches were applied to exome data to identify candidate risk variants outside of known risk genes. Findings were verified in a collection of Canadian HBOC patients of European ancestry (FBRCAX), in an independent group of Canadian BC patients (CHUM-BC) and controls (CARTaGENE), as well as in individuals from The Cancer Genome Atlas (TCGA) and the UK Biobank (UKB). Rare LoF variants were uncovered in MDM1 and NBEAL1 in Greek and Canadian HBOC patients. We also report prioritized missense variants SETBP1:c.4129G > C and C7orf34:c.248C > T. These variants comprise promising candidates whose role in cancer pathogenicity needs to be explored further.

BRCA variant classification is improved by Japanese SNP data and correlate with response to PARP inhibition in MH GUIDE

Abstract Background The BRCA1/2 genes have emerged as critical biomarkers, particularly for patients with hereditary breast and ovarian cancer (HBOC). MH BRCA classifies variants based on ACMG guidelines. Clinical interpretation of NGS results by MH GUIDE provides clinicians with treatment recommendations to cancer based on expert curated biomarker knowledge. Methods MH BRCA was compared to the clinical interpretation of three Japanese HBOC studies. Population-frequency (PF) data from the 1000 Genomes Project (1000G) and the Japanese genome cohort of Tohoku Medical Megabank Organization (ToMMo) were analyzed. Based on functional evidence for DNA damage response, we correlated the ACMG index with the predicted response to PARP inhibition by MH GUIDE. Finally, BRCA classifications of 350 patients with breast and/or ovarian cancer sequenced at the Yamanashi Central Hospital (YPCH) were compared to MH BRCA. Results MH BRCA using the integrated ToMMo data revealed 40% increased accuracy in benign classification. The Japanese-cohort in 1000G represents Conclusion We enhanced the performance of MH BRCA for Japanese HBOC patients by integrating data from the ToMMo database. Our collaboration with YPCH revealed that MH BRCA supports a standardized process for assessment of pathogenicity. Contextualizing of MH BRCA classifications with MH GUIDE supports the treatment strategy of PARP inhibition with the benefit on fine-resolution of hypermorphic and hypomorphic BRCA mutations.

Comprehensive mutation detection of BRCA1/2 genes reveals large genomic rearrangements contribute to hereditary breast and ovarian cancer in Chinese women

BackgroundMutated BRCA1/2 genes are associated with hereditary breast and ovarian cancer (HBOC). So far most of the identified BRCA1/2 pathogenic variants are single nucleotide variants (SNVs) or insertions/deletions (Indels). However, large genomic rearrangements (LGRs) such as copy number variants (CNVs) are also playing an important role in HBOC predisposition. Their frequency and spectrum have been well studied in western populations but remain largely unknown for Chinese population.MethodsPeripheral blood samples were collected from 218 unrelated familial breast and/or ovarian cancer (FBOC) patients living in Eastern China. PCR-based Sanger sequencing and panel-based next-generation sequencing (NGS) were performed to detect pathogenic SNVs and Indels in BRCA1/2 genes. For the patients lacking small pathogenic variants, multiplex ligation dependent probe amplification (MLPA) assay was conducted to screen for LGRs.ResultsIn total, we identified 44 samples (20.1%) carrying small pathogenic variants (26 in BRCA1 and 18 in BRCA2, respectively). Among the rest of 174 samples, five were found carrying novel deleterious LGRs in BRCA1 which are exon5-7dup (1 patient), exon13-14dup (2 patients), and exon1-22del (2 patients). No LGR was found in BRCA2. Overall, LGRs accounted for 16.1% (5/31) of BRCA1 pathogenic variants, and were detected in 2.3% (5/218) of all FBOC patients.,ConclusionsLGR variants in BRCA1 gene play a significant role in Chinese HBOC patients. MLPA or other similar LGR-detecting methods should be recommended along with nucleotide sequencing as the initial screening approach for Chinese HBOC women.