Exome Sequencing Identifies Carriers of the Autosomal Dominant Cancer Predisposition Disorders Beyond Current Practice Guideline Recommendations.

PURPOSE: The autosomal dominant cancer predisposition disorders hereditary breast and ovarian cancer (HBOC) and Lynch syndrome (LS) are genetic conditions for which early identification and intervention have a positive effect on the individual and public health. The goals of this study were to determine whether germline genetic screening using exome sequencing could be used to efficiently identify carriers of HBOC and LS. METHODS: Participants were recruited from three geographically and racially diverse sites in the United States (Rochester, MN; Phoenix, AZ; Jacksonville, FL). Participants underwent Exome+ sequencing (Helix Inc, San Mateo, CA) and return of results for specific genetic findings: HBOC (BRCA1 and BRCA1) and LS (MLH1, MSH2, MSH6, PMS2, and EPCAM). Chart review was performed to collect demographics and personal and family cancer history. RESULTS: To date, 44,306 participants have enrolled in Tapestry. Annotation and interpretation of all variants in genes for HBOC and LS resulted in the 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). More than half of these participants (52.1%) were newly diagnosed carriers with HBOC and LS. In all, 39.2% of HBOC/LS carriers did not satisfy National Comprehensive Cancer Network (NCCN) criteria for genetic evaluation. NCCN criteria were less commonly met in underrepresented minority populations versus self-reported White race (51.5% v 37.5%, P = .028). CONCLUSION: Our results emphasize the need for wider utilization of germline genetic sequencing for enhanced screening and detection of individuals who have LS and HBOC cancer predisposition syndromes.

A Molecular Characterization of the Allelic Expression of the BRCA1 Founder Δ9-12 Pathogenic Variant and Its Potential Clinical Relevance in Hereditary Cancer.

Hereditary breast and ovarian cancer (HBOC) syndrome is a genetic condition that increases the risk of breast cancer by 80% and that of ovarian cancer by 40%. The most common pathogenic variants (PVs) causing HBOC occur in the BRCA1 gene, with more than 3850 reported mutations in the gene sequence. The prevalence of specific PVs in BRCA1 has increased across populations due to the effect of founder mutations. Therefore, when a founder mutation is identified, it becomes key to improving cancer risk characterization and effective screening protocols. The only founder mutation described in the Mexican population is the deletion of exons 9 to 12 of BRCA1 (BRCA1Δ9-12), and its description focuses on the gene sequence, but no transcription profiles have been generated for individuals who carry this gene. In this study, we describe the transcription profiles of cancer patients and healthy individuals who were heterozygous for PV BRCA1Δ9-12 by analyzing the differential expression of both alleles compared with the homozygous BRCA1 control group using RT-qPCR, and we describe the isoforms produced by the BRCA1 wild-type and BRCA1Δ9-12 alleles using nanopore long-sequencing. Using the Kruskal-Wallis test, our results showed a similar transcript expression of the wild-type allele between the healthy heterozygous group and the homozygous BRCA1 control group. An association between the recurrence and increased expression of both alleles in HBOC patients was also observed. An analysis of the sequences indicated four wild-type isoforms with diagnostic potential for discerning individuals who carry the PV BRCA1Δ9-12 and identifying which of them has developed cancer.

Targeted sequencing for hereditary breast and ovarian cancer in BRCA1/2-negative families reveals complex genetic architecture and phenocopies.

Approximately 20% of breast cancer cases are attributed to increased family risk, yet variation in BRCA1/2 can only explain 20%-25% of cases. Historically, only single gene or single variant testing were common in at-risk family members, and further sequencing studies were rarely offered after negative results. In this study, we applied an efficient and inexpensive targeted sequencing approach to provide molecular diagnoses in 245 human samples representing 134 BRCA mutation-negative (BRCAX) hereditary breast and ovarian cancer (HBOC) families recruited from 1973 to 2019 by Dr. Henry Lynch. Sequencing identified 391 variants, which were functionally annotated and ranked based on their predicted clinical impact. Known pathogenic CHEK2 breast cancer variants were identified in five BRCAX families in this study. While BRCAX was an inclusion criterion for this study, we still identified a pathogenic BRCA2 variant (p.Met192ValfsTer13) in one family. A portion of BRCAX families could be explained by other hereditary cancer syndromes that increase HBOC risk: Li-Fraumeni syndrome (gene: TP53) and Lynch syndrome (gene: MSH6). Interestingly, many families carried additional variants of undetermined significance (VOUSs) that may further modify phenotypes of syndromic family members. Ten families carried more than one potential VOUS, suggesting the presence of complex multi-variant families. Overall, nine BRCAX HBOC families in our study may be explained by known likely pathogenic/pathogenic variants, and six families carried potential VOUSs, which require further functional testing. To address this, we developed a functional assay where we successfully re-classified one family's PMS2 VOUS as benign.

Walking the tightrope: Fertility preservation among hereditary breast and ovarian Cancer syndrome Previvors.

INTRODUCTION: Fertility-related concerns cause significant anxiety among patients with Hereditary Breast and Ovarian Cancer Syndrome (HBOC). The Society of Gynecologic Oncology and the American Society for Reproductive Medicine recommend patients diagnosed with HBOC receive early referral to a reproductive endocrinologist. However, evidence about fertility trends in this patient population are limited and guidelines are scarce. The aim of this study is to compare fertility preservation among patients with HBOC to control patients undergoing fertility treatment without a diagnosis of infertility. METHODS: This retrospective study included patients who presented to a single academic institution for fertility preservation in the setting of diagnosis of HBOC. In this study, HBOC patients are referred to as those who had tested positive for pathogenic mutations in BRCA1, BRCA2 or were at high-risk for HBOC based on a strong family history (defined as >3 family members diagnosed with HBOC) without a genetic mutation. HBOC patients were matched in a 1:1 fashion to a control group undergoing fertility preservation without a diagnosis of infertility or HBOC. All analysis was done using SPSS version 9.4 (SAS Institute, Cary, NC). RESULTS: Between August 1st, 2016 and August 1st, 2022, 81 patients presented to the study center for consultation in the setting of HBOC. Of those who presented, 48 (59.2%) ultimately underwent oocyte cryopreservation and 33 (40.7%) underwent embryo cryopreservation. Patients who underwent oocyte cryopreservation due to BRCA1 status were more likely to present for fertility consultation at a younger age compared to control patients (32.6 vs. 34.7 years, p = 0.03) and were more likely to undergo oocyte cryopreservation at a younger age (32.1 vs. 34.6 years, p = 0.007). There was no difference in age at initial consultation or age at procedure for patients with BRCA2 or patients with a strong family history compared to control patients (p > 0.05). There was no difference in the mean age of patients with HBOC at presentation for consultation for embryo cryopreservation or the mean age the patient with HBOC underwent embryo cryopreservation compared to control patients (p > 0.05). Patients with BRCA1 or BRCA2 did not have expedited time from consultation to first cycle start (p > 0.05). After adjusting for factors including anti-Müllerian hormone (AMH) level and age, patients considered in the HBOC group due to family history had less time between consultation and oocyte cryopreservation cycle compared to control patients. (179 vs. 317 days, p = 0.045). There was no difference in time from consultation to starting cycle for embryo cryopreservation for patients with HBOC compared to controls (p > 0.05). CONCLUSION: Patients with HBOC did not undergo expedited fertility treatment compared to control patients undergoing oocyte and embryo cryopreservation for non-infertility reasons. Patients diagnosed with BRCA1 had more oocytes retrieved compared to the control population which is possibly due to earlier age of presentation in the setting of recommended age of risk reducing surgery being age 35-40. When age matched, cycle outcomes did not differ between HBOC and control patients. Given the known cancer prevention benefit and recommendations for risk-reducing surgery, future studies should focus on guidelines for fertility preservation for patients with HBOC.

The Genetic Paradigm of Hereditary Breast and Ovarian Cancer (HBOC) in the Afro-Caribbean Population.

Differences in tumor biology and genetic predisposition have been suggested as factors influencing overall survival and increased mortality in Black breast and ovarian cancer patients. Therefore, it is key to evaluate genetic susceptibilities in Afro-Caribbean patients because the black population in the US is not homogeneous. Identifying a high incidence of hereditary breast and ovarian cancer (HBOC) in Afro-Caribbean countries can lead to understanding the pattern of inherited traits in US-Caribbean immigrants and their subsequent generations. The paucity of projects studying the genetic landscape in these populations makes it difficult to design studies aimed at optimizing screening and prophylaxis strategies, which in turn, improve survival and mortality rates. This scoping review identifies and categorizes current research on the genetic paradigm of HBOC in the Afro-Caribbean population. We performed an evaluation of the evidence and generated a summary of findings according to preferred reporting items for systematic review and meta-analysis (PRISMA) Extension for Scoping Reviews guidelines. We included articles that assessed the incidence and prevalence of pathologic germline mutations and experience/barriers for genetic testing in Afro-Caribbean Countries and US-Caribbean patients. Our results highlight countries where genetic landscapes remain severely understudied and support recommending multigene testing in Caribbean-born patients. They highlight a need for further research on the genetic paradigm of HBOC in the Afro-Caribbean population to improve genetic testing/counseling and the subsequent adoption of early detection and risk reduction strategies.

Psychosocial barriers and facilitators for cascade genetic testing in hereditary breast and ovarian cancer: a scoping review.

Despite increased awareness and availability of genetic testing for hereditary breast and ovarian cancer (HBOC) syndrome for over 20 years, there is still significant underuse of cascade genetic testing among at-risk relatives. This scoping review synthesized evidence regarding psychosocial barriers and facilitators of family communication and/or uptake of cascade genetic testing in relatives from HBOC families. Search terms included 'hereditary breast and ovarian cancer' and 'cascade genetic testing' for studies published from 2012-2022. Through searching common databases, and manual search of references, 480 studies were identified after excluding duplications. Each article was reviewed by two researchers independently and 20 studies were included in the final analysis. CASP, RoBANS 2.0, RoB 2.0, and MMAT were used to assess the quality of included studies. A convergent data synthesis method was used to integrate evidence from quantitative and narrative data into categories and subcategories. Evidence points to 3 categories and 12 subcategories of psychosocial barriers and facilitators for cascade testing: (1) facilitators (belief in health protection and prevention; family closeness; decisional empowerment; family support, sense of responsibility; self-efficacy; supportive health professionals); (2) bidirectional concepts (information; perception of genetic/cancer consequences; negative emotions and attitude); and (3) barriers (negative reactions from family and negative family dynamics). Healthcare providers need to systematically evaluate these psychosocial factors, strengthen facilitators and alleviate barriers to promote informed decision-making for communication of genetic test results and uptake of genetic testing. Bidirectional factors merit special consideration and tailored approaches, as they can potentially have a positive or negative influence on family communication and uptake of genetic testing.

Uptake of screening and risk-reducing recommendations among women with hereditary breast and ovarian cancer syndrome due to pathogenic BRCA1/2 variants evaluated at a large urban comprehensive cancer center.

PURPOSE: Carriers of pathogenic variants in BRCA1/2 have an elevated lifetime cancer risk warranting high-risk screening and risk-reducing procedures for early detection and prevention. We report on prevention practices among women with pathogenic BRCA variants in order to document follow through with NCCN recommendations and to identify barriers to guideline-recommended care. METHODS: Our cohort included women who had genetic testing through a cancer genetic clinic and completed a 54-item questionnaire to measure socio-demographics, medical history, rates of cancer screening and risk-reducing surgery, disclosure of test results, and cancer worry. Outcomes included rates of completion of risk-reducing salpingo-oophorectomy (RRSO), risk-reducing mastectomy (RRM), and NCCN risk-reducing and age-dependent screening guidelines (version 3.2019). Multivariable logistic regression analyses were used to evaluate potential predictors of these outcomes. RESULTS: Of 129 evaluable women with pathogenic BRCA1/2 variants, 95 (74%) underwent RRSO and 77 (60%) had RRM, respectively, and 107 (83%) were considered adherent to NCCN guidelines. Women with a history of breast or ovarian cancer were more likely to have RRM (OR = 4.38; 95% CI 1.80-11.51; p = 0.002). Increasing age was associated with an increased likelihood of RRSO (OR = 1.05; 95% CI 1.01-1.09; p = 0.019) and decreased likelihood for RRM (OR = 0.95; 95% CI 0.92-0.99; p = 0.013). Women who had RRM were 3 times more likely to undergo RRSO (OR = 2.81; 95% CI 1.10-7.44; p = 0.025). Women who had genetic testing after June 2013 were less likely to have RRM than those tested before June 2013 (OR = 0.42; 95% CI 0.18-0.95; p = 0.040. None of the other measured factors were associated with rates of RRSO, RRM or follow through with NCCN recommendations. There was near universal (127/129) reported disclosure of genetic test results to family members, resulting in the discovery of a median of 1 relative with a pathogenic variant (range = 0-8). CONCLUSION: An evaluation of follow up practice in a cohort of women with pathogenic variants in BRCA1/2 revealed high rates of reported completion of screening and surgical risk-reducing recommendations. Educational efforts should continue to reinforce the importance of follow-through with guideline recommended care among this high-risk group.

Ovarian surveillance including endometrial cytology for patients with hereditary breast and ovarian cancer before risk-reducing salpingo-oophorectomy: A retrospective analysis.

AIM: Ovarian surveillance in women with hereditary breast and ovarian cancer who do not undergo risk-reducing salpingo-oophorectomy has been controversial. Therefore, this study aimed to demonstrate the clinical features of ovarian surveillance at our institution using a technique that combines serum cancer antigen 125 measurements, transvaginal ultrasonography, and uterine endometrial cytology. METHODS: We retrospectively examined 65 women, who had not undergone risk-reducing salpingo-oophorectomy diagnosed with hereditary breast and ovarian cancer between 2000 and 2021 at our hospital. Clinical information was obtained and analyzed through a chart review. The details of the treatment course were reviewed for patients who had developed ovarian cancer. RESULTS: Overall, 5 of the 65 women were diagnosed with ovarian cancer based on abnormal findings during periodic surveillance. All patients who developed ovarian cancer were asymptomatic, even if the cancer was at an advanced stage. Two of the 65 patients had endometrial cytology abnormalities, both of whom had ovarian cancer. All patients who developed ovarian cancer underwent primary debulking surgery, and complete gross resection was achieved. None of the patients experienced ovarian cancer recurrence. CONCLUSIONS: The ovarian surveillance strategy at our institution for women with hereditary breast and ovarian cancer who do not undergo risk-reducing salpingo-oophorectomy can identify asymptomatic ovarian cancer and contribute to achieving complete gross resection during primary surgery. Ovarian surveillance may contribute to a reduction in ovarian cancer mortality.

Young Women's Perspectives on Being Screened for Hereditary Breast and Ovarian Cancer Risk During Routine Primary Care.

PURPOSE: The U.S. Preventive Services Task Force recommends screening women to identify individuals eligible for genetic counseling based on a priori hereditary breast and ovarian cancer syndrome (HBOC) risk (i.e., risk assessment). However, risk assessment has not been widely integrated into primary care. This qualitative study explored young women's views on implementing routine HBOC risk assessment with a focus on equity and patient-centeredness. METHODS: We conducted group discussions with young women (aged 21-40 years) receiving care in an integrated health care system. Discussion groups occurred in two phases and used a modified deliberative approach that included a didactic component and prioritized developing consensus. Twenty women participated in one of three initial small group discussions (phase one). All 20 were invited to participate in a subsequent large group discussion (phase two), and 15 of them attended. FINDINGS: Key themes and recommendations were as follows. Risk assessment should be accessible, contextualized, and destigmatized to encourage participation and reduce anxiety, particularly for women who do not know their family history. Providers conducting risk assessments must be equipped to address women's informational needs, relieve emotionality, and plan next steps after positive screens. Finally, to minimize differential screening uptake, health care systems must prioritize equity in program design and contribute to external educational and outreach efforts. CONCLUSION: Young women see pragmatic opportunities for health systems to optimize HBOC screening implementation.

Cascade screening in HBOC and Lynch syndrome: guidelines and procedures in a UK centre.

In the 33 years since the first diagnostic cancer predisposition gene (CPG) tests in the Manchester Centre for Genomic Medicine, there has been substantial changes in the identification of index cases and cascade testing for at-risk family members. National guidelines in England and Wales are usually determined from the National Institute of healthcare Evidence and these have impacted on the thresholds for testing BRCA1/2 in Hereditary Breast Ovarian Cancer (HBOC) and in determining that all cases of colorectal and endometrial cancer should undergo screening for Lynch syndrome. Gaps for testing other CPGs relevant to HBOC have been filled by the UK Cancer Genetics Group and CanGene-CanVar project (web ref. https://www.cangene-canvaruk.org/ ). We present time trends (1990-2020) of identification of index cases with germline CPG variants and numbers of subsequent cascade tests, for BRCA1, BRCA2, and the Lynch genes (MLH1, MSH2, MSH6 and PMS2). For BRCA1/2 there was a definite increase in the proportion of index cases with ovarian cancer only and pre-symptomatic index tests both doubling from 16 to 32% and 3.2 to > 8% respectively. A mean of 1.73-1.74 additional family tests were generated for each BRCA1/2 index case within 2 years. Overall close to one positive cascade test was generated per index case resulting in > 1000 risk reducing surgery operations. In Lynch syndrome slightly more cascade tests were performed in the first two years potentially reflecting the increased actionability in males with 42.2% of pre-symptomatic tests in males compared to 25.8% in BRCA1/2 (p < 0.0001).

EMQN best practice guidelines for genetic testing in hereditary breast and ovarian cancer.

Hereditary Breast and Ovarian Cancer (HBOC) is a genetic condition associated with increased risk of cancers. The past decade has brought about significant changes to hereditary breast and ovarian cancer (HBOC) diagnostic testing with new treatments, testing methods and strategies, and evolving information on genetic associations. These best practice guidelines have been produced to assist clinical laboratories in effectively addressing the complexities of HBOC testing, while taking into account advancements since the last guidelines were published in 2007. These guidelines summarise cancer risk data from recent studies for the most commonly tested high and moderate risk HBOC genes for laboratories to refer to as a guide. Furthermore, recommendations are provided for somatic and germline testing services with regards to clinical referral, laboratory analyses, variant interpretation, and reporting. The guidelines present recommendations where 'must' is assigned to advocate that the recommendation is essential; and 'should' is assigned to advocate that the recommendation is highly advised but may not be universally applicable. Recommendations are presented in the form of shaded italicised statements throughout the document, and in the form of a table in supplementary materials (Table S4). Finally, for the purposes of encouraging standardisation and aiding implementation of recommendations, example report wording covering the essential points to be included is provided for the most common HBOC referral and reporting scenarios. These guidelines are aimed primarily at genomic scientists working in diagnostic testing laboratories.

[Return of Individual Genomic Results to Germline Pathogenic Variant Carriers of Hereditary Cancer in Population Based Cohort Study].

Return of individual genomic results(ROGR)to participants in population-based biobank has been rarely conducted in research settings, and the procedure of ROGR performed in foreign countries may not be simply applied to Japanese participants, because of the difference in social background. The Tohoku Medical Megabank Project, which was launched in 2012 aiming to build a foundation of personalized genomic medicine, obtained the consent from research participants by explaining the future possibility of ROGR. After careful consideration of appropriate procedure for ROGR, individual genomic results were returned to 111 pathogenic variant(PV)carriers of hereditary breast and ovarian cancer syndrome(HBOC)or Lynch syndrome(LS)based on 50,000 whole genome sequencing(WGS)data in FY 2022. Since majority of the participants has no cancer diagnosis, participants' right to not know was carefully considered. In addition, the variants to be returned were carefully evaluated by using multiple databases, and the WGS results of the participants were further confirmed by the single- site analysis. When the genomic results were returned, the participants were informed about clinical risk surveillance at the hospital. Seventy-eight and 33 PV carriers of HBOC and LS, respectively, participated in the study. Most participants were in their 30s or 40s. Unexpectedly, validation testing results of 12 LS participants were found to be negative or variant of uncertain significance, because detecting these variants by WGS were technically challenging. Twenty-eight participants (HBOC 20, LS 8)had been diagnosed as cancer, and 6 females who had breast cancer were genetically diagnosed as HBOC and underwent or planned risk-reducing surgery. Eighteen participants refused to undergo clinical risk surveillance because of the medical expense that is not covered by health insurance and the burden of visiting the hospital. The opportunity to undergo medical surveillance should be provided to population-based cohort participants who carry actionable pathogenic variants, and ROGR to general population should be promoted to create the base of personalized genomic medicine.

Systematic review of the molecular basis of hereditary breast and ovarian cancer syndrome in Brazil: the current scenario.

BACKGROUND: A detailed understanding of the genetic basis of cancer is of great interest to public health monitoring programs. Although many studies have been conducted in Brazil, a global view on the molecular profile related to hereditary breast and ovarian cancer (HBOC) in this large and heterogeneous population is lacking. METHODS: A systematic review following the PRISMA guidelines was conducted in three electronic databases (PubMed, BIREME and SciELO). Brazilian studies covering molecular analysis of genes related to HBOC, published until December 2023, were considered. RESULTS: We identified 35 original studies that met all the inclusion criteria. A total of 137 distinct mutations were found in the BRCA1 gene, but four of them corresponded to 44.5% of all mutations found in this gene. The c.5266dupC BRCA1 mutation was responsible for 26.8% of all pathogenic mutations found in the BRCA1 gene in patients with clinical criteria for HBOC from the Brazilian population. Considering all studies that track this mutation in the BRCA1 gene, we found a frequency of 2% (120/6008) for this mutation in Brazilian patients. In the BRCA2 gene, the four most frequent mutations corresponded to 29.2% of pathogenic mutations. Even though it was tracked by few studies, the c.156_157insAlu mutation was responsible for 9.6% of all pathogenic mutations reported in the BRCA2 gene. Seventeen studies found pathogenic mutations in other non-BRCA genes, the c.1010G > A mutation in the TP53 gene being the most frequent one. Considering all studies that screened for this specific mutation in patients with the clinical criteria for HBOC, the frequency of c.1010G > A was estimated at 1.83% (61/3336). CONCLUSIONS: Despite significant molecular heterogeneity among mutations in HBOC patients from Brazil, three mutations deserve to be highlighted, c.5266dupC, c.156_157insAlu and c.1010G > A in the BRCA1, BRCA2 and TP53 genes, respectively. With more than 200 records, these three mutations play a vital role in the pathology of breast and ovarian cancer in Brazil. The data collected shed light on the subject, but there is still not enough data from certain subpopulations.

The frequency and pathogenicity of BRCA1 and BRCA2 variants in the general Japanese population.

Hereditary breast and ovarian cancer syndrome (HBOC) resulting from pathogenic variants of BRCA1 or BRCA2 is the most common and well-documented hereditary tumor. Although founder variants have been identified in population-based surveys in various countries, the types of variants are not uniform across races and regions. Recently, the Tohoku Medical Megabank Organization (ToMMo) released whole-genome sequence data including approximately 54,000 individuals from the general population of the Tohoku area in Japan. We analyzed these data and comprehensively identified the prevalence of BRCA1/2 pathogenic and truncating variants. We believe that an accurate understanding of the unique distribution and characteristics of pathogenic BRCA1/2 variants in Japan through this analysis will enable better surveillance and intervention for HBOC patients, not only in Japan but also worldwide.

Germline mutational variants of Turkish ovarian cancer patients suspected of Hereditary Breast and Ovarian Cancer (HBOC) by next-generation sequencing.

Hereditary Breast and Ovarian Cancer (HBOC) syndrome is characterized by an increased risk of developing breast cancer (BC) and ovarian cancer (OC) due to inherited genetic mutations. Understanding the genetic variants associated with HBOC is crucial for identifying individuals at high risk and implementing appropriate preventive measures. The study included 630 Turkish OC patients with confirmed diagnostic criteria of The National Comprehensive Cancer Network (NCCN) concerning HBOC. Genomic DNA was extracted from peripheral blood samples, and targeted Next-generation sequencing (NGS) was performed. Bioinformatics analysis and variant interpretation were conducted to identify pathogenic variants (PVs). Our analysis revealed a spectrum of germline pathogenic variants associated with HBOC in Turkish OC patients. Notably, several pathogenic variants in BRCA1, BRCA2, and other DNA repair genes were identified. Specifically, we observed germline PVs in 130 individuals, accounting for 20.63% of the total cohort. 76 distinct PVs in genes, BRCA1 (40 PVs), BRCA2 (29 PVs), ATM (1 PV), CHEK2 (2 PVs), ERCC2 (1 PV), MUTYH (1 PV), RAD51C (1 PV), and TP53 (1PV) and also, two different PVs (i.e., c.135-2 A>G p.? in BRCA1 and c.6466_6469delTCTC in BRCA2) were detected in a 34-year-old OC patient. In conclusion, our study contributes to a better understanding of the genetic variants underlying HBOC in Turkish OC patients. These findings provide valuable insights into the genetic architecture of HBOC in the Turkish population and shed light on the potential contribution of specific germline PVs to the increased risk of OC.

Optical Genome Mapping Reveals the Landscape of Structural Variations and Their Clinical Significance in HBOC-Related Breast Cancer.

BACKGROUND: Structural variations (SVs) are common genetic alterations in the human genome. However, the profile and clinical relevance of SVs in patients with hereditary breast and ovarian cancer (HBOC) syndrome (germline BRCA1/2 mutations) remains to be fully elucidated. METHODS: Twenty HBOC-related cancer samples (5 breast and 15 ovarian cancers) were studied by optical genome mapping (OGM) and next-generation sequencing (NGS) assays. RESULTS: The SV landscape in the 5 HBOC-related breast cancer samples was comprehensively investigated to determine the impact of intratumor SV heterogeneity on clinicopathological features and on the pattern of genetic alteration. SVs and copy number variations (CNVs) were common genetic events in HBOC-related breast cancer, with a median of 212 SVs and 107 CNVs per sample. The most frequently detected type of SV was insertion, followed by deletion. The 5 HBOC-related breast cancer samples were divided into SVhigh and SVlow groups according to the intratumor heterogeneity of SVs. SVhigh tumors were associated with higher Ki-67 expression, higher homologous recombination deficiency (HRD) scores, more mutated genes, and altered signaling pathways. Moreover, 60% of the HBOC-related breast cancer samples displayed chromothripsis, and 8 novel gene fusion events were identified by OGM and validated by transcriptome data. CONCLUSIONS: These findings suggest that OGM is a promising tool for the detection of SVs and CNVs in HBOC-related breast cancer. Furthermore, OGM can efficiently characterize chromothripsis events and novel gene fusions. SVhigh HBOC-related breast cancers were associated with unfavorable clinicopathological features. SVs may therefore have predictive and therapeutic significance for HBOC-related breast cancers in the clinic.

A case of simultaneous breast cancer and ovarian cancer based on a hereditary breast and ovarian cancer syndrome.

We experienced a relatively rare case of synchronous breast and ovarian cancer in a patient with hereditary breast and ovarian cancer syndrome (HBOC). Here, we report the usefulness of laparoscopic examination to determine the subsequent treatment strategy in cases of suspected concurrent multiple carcinomas. Our patient was diagnosed with breast cancer following detection of a right breast mass. She was diagnosed with HBOC as she was found to be harboring a germline pathogenic variant of breast cancer susceptibility gene 1 (BRCA1). Preoperative images suggested the presence of neoplastic masses in the abdominal cavity, and the possibility of metastatic peritoneal dissemination of breast cancer or concurrent overlapping of gynecological malignancies was considered. We decided to employ laparoscopic examination, and if simultaneous overlapping of cancers was suspected, we planned to further evaluate whether primary debulking surgery (PDS) for gynecological cancer was possible or not. Laparoscopy revealed the presence of ovarian cancer with neoplastic lesions on the bilateral ovaries and disseminations in the pelvic and abdominal cavities. The total predictive index was 0; therefore, PDS was considered feasible. We performed a total mastectomy, followed by laparotomy, and optimal surgery was achieved. The final diagnosis was simultaneous stage IIB invasive ductal breast carcinoma and stage IIIC high-grade serous ovarian carcinoma. In this case of suspected concurrent multiple carcinomas, laparoscopy was beneficial for decision-making regarding subsequent surgical treatment. We believe that the use of laparoscopy will enable simultaneous surgery for breast cancer and ovarian cancer to become one of the treatment strategies in the future.

Impact of non-BRCA genes in the indication of risk-reducing surgery in hereditary breast and ovarian cancer syndrome (HBOC).

Hereditary breast and ovarian cancer syndrome (HBOC) is associated with other genes beyond BRCA. The performance of prophylactic bilateral mastectomy (PBM) and risk-reducing salpingo-oophorectomy (RRSO) are primary prevention measures that can be recommended depending on the type of pathogenic/likely pathogenic (P/LP) variant detected or family history. Descriptive, retrospective, and observational audit. Between the years 2015 to May 2023, a total of 288 families were studied by a multigene panel using NGS. Statistical analysis was performed using IBM SPSS Statistics 22. Non-BRCA P/LP variants were detected in 38 families (84.2% females and 15.8% males); 18 in ATM (44.7 %), 7 in CHEK2 (18.4%), 5 in TP53 (13.2%), 2 in PTEN (5.3%), 2 in PALB2 (5.3%), 1 in RAD51C (2.6%), 1 in BRIP1 (2.6%), 1 in CDH1 (2.6%) and 1 in RAD51D (2.6%). Risk-reducing surgery was recommended in 18 patients (PBM in 18 [46.2 %] and RRSO in 5 [13.2%]). Given the results of our study, we support the recommendations of the guidelines on the use of multigene panels in the study of HBOC. Knowing P/LP variants beyond BRCA1 and 2 has an impact on the follow-up and primary and secondary prevention of affected families.

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.

Extended genetic analysis and tumor characteristics in over 4600 women with suspected hereditary breast and ovarian cancer.

BACKGROUND: Genetic screening for pathogenic variants (PVs) in cancer predisposition genes can affect treatment strategies, risk prediction and preventive measures for patients and families. For decades, hereditary breast and ovarian cancer (HBOC) has been attributed to PVs in the genes BRCA1 and BRCA2, and more recently other rare alleles have been firmly established as associated with a high or moderate increased risk of developing breast and/or ovarian cancer. Here, we assess the genetic variation and tumor characteristics in a large cohort of women with suspected HBOC in a clinical oncogenetic setting. METHODS: Women with suspected HBOC referred from all oncogenetic clinics in Sweden over a six-year inclusion period were screened for PVs in 13 clinically relevant genes. The genetic outcome was compared with tumor characteristics and other clinical data collected from national cancer registries and hospital records. RESULTS: In 4622 women with breast and/or ovarian cancer the overall diagnostic yield (the proportion of women carrying at least one PV) was 16.6%. BRCA1/2 PVs were found in 8.9% of women (BRCA1 5.95% and BRCA2 2.94%) and PVs in the other breast and ovarian cancer predisposition genes in 8.2%: ATM (1.58%), BARD1 (0.45%), BRIP1 (0.43%), CDH1 (0.11%), CHEK2 (3.46%), PALB2 (0.84%), PTEN (0.02%), RAD51C (0.54%), RAD51D (0.15%), STK11 (0) and TP53 (0.56%). Thus, inclusion of the 11 genes in addition to BRCA1/2 increased diagnostic yield by 7.7%. The yield was, as expected, significantly higher in certain subgroups such as younger patients, medullary breast cancer, higher Nottingham Histologic Grade, ER-negative breast cancer, triple-negative breast cancer and high grade serous ovarian cancer. Age and tumor subtype distributions differed substantially depending on genetic finding. CONCLUSIONS: This study contributes to understanding the clinical and genetic landscape of breast and ovarian cancer susceptibility. Extending clinical genetic screening from BRCA1 and BRCA2 to 13 established cancer predisposition genes almost doubles the diagnostic yield, which has implications for genetic counseling and clinical guidelines. The very low yield in the syndrome genes CDH1, PTEN and STK11 questions the usefulness of including these genes on routine gene panels.