Targeted genotyping for recurring variants in cancer susceptibility genes in non-Ashkenazi Jewish patients with breast cancer diagnosed ≥50 years.

PURPOSE: Several recurring pathogenic variants (PVs) in BRCA1/BRCA2 and additional cancer susceptibility genes are described in the ethnically diverse Israeli population. Since 2019, testing for these recurring PVs is reimbursed unselectively for all patients with breast cancer (BC) in Israel. The aim was to evaluate the yield of genotyping for these PVs in non-Ashkenazi Jewish (AJ) patients with BC diagnosed ≥age 50 years. METHODS: Clinical and genotyping data of all patients with BC undergoing oncogenetic counseling at the Oncology Institute at Sheba Medical Center from June 2017 to December 2023 were reviewed. RESULTS: Of 2706 patients with BC (mean age at diagnosis, 54 years; range, 20-92 years) counseled, 515 patients of non-AJ (all four grandparents) descent, diagnosed ≥age 50 years of age were genotyped, 55 with triple-negative BC (TNBC) and 460 with non-TNBC. One of the recurring PVs in BRCA1/BRCA2 were detected in 12.7% (7/55) of TNBC patients and 0.65% (3/460) of non-TNBC. One patient with non-TNBC had PMS2 PV. Low-penetrance variants were found in 2.5% of genotyped TNBC and in 3.7% of patients with non-TNBC, including CHEK2 c.499G>A (n = 3), APC c.3920T > A (n = 4), and heterozygous MUTYH c.1187G>A (n = 5). Following first-pass genotyping, 146 patients performed multigene panel testing, none carried a BRCA1/BRCA2 PV, and only 5/127 non-TNBC (3.9%) harbored PVs in CHEK2 (n = 2, c.846+1G>C and c.592+3A>T), ATM c.103C>T (n = 2), and NBN c.966C>G (n = 1). CONCLUSIONS: The observed low rates of PV detection in non-AJ non-TNBC cases ≥age 50 years at diagnosis, mostly for clinically insignificant variants, questions the justification of unselected genotyping in this subset of patients.

Clinical breast exam contribution to breast cancer diagnosis in BRCA mutation carriers vs. average to intermediate risk women.

PURPOSE: The contribution of clinical breast exam (CBE) to breast cancer diagnosis in average risk women undergoing regular screening mammography is minimal. To evaluate the role of CBE in high-risk women, we compared BC diagnosis by CBE in BRCA mutation carriers undergoing regular BC surveillance to average to intermediate risk women undergoing regular breast cancer screening. METHODS: A retrospective chart review of all consecutive screening visits of BRCA mutation carriers (January 2012-October 2022) and average to intermediate risk women (November 2016-December 2022) was completed. Women with histologically confirmed BC diagnosis were included. Additional CBE yield for BC diagnosis, defined as the percentage of all BC cases detected by CBE alone, was assessed in both groups. RESULTS: Overall, 12,997 CBEs were performed in 1,328 BRCA mutation carriers in whom 134 BCs were diagnosed. In 7,949 average to intermediate risk women who underwent 15,518 CBEs, 87 BCs were diagnosed. CBE contributed to BC diagnosis in 3 (2%) BRCA mutation carriers and 3 (4%) non-carriers. In both groups, over 4,000 CBEs were needed in order to diagnose one cancer. In all 3 BRCA mutation carriers BC was palpated during the surveillance round that did not include MRI. In the average to intermediate risk group, 2 of 3 cancers diagnosed following CBE findings were in a different location from the palpable finding. CONCLUSIONS: The contribution of CBE to BC diagnosis is marginal for all women including BRCA mutation carriers. In BRCA mutation carriers, CBE appears redundant during the MRI surveillance round.

Breast cancer diagnosed after age 70 years in Israeli BRCA1/BRCA2 pathogenic sequence variant carriers: a single institution experience.

PURPOSE: A semi-annual surveillance scheme from age 25 to 30 years is offered to BRCA1/BRCA2 pathogenic sequence variants (PSVs) carriers for early detection of breast cancer (BC). There is a paucity of data on the yield of adhering to this scheme beyond 70 years of age. METHODS: Female BRCA1/BRCA2 PSV carriers followed at the Meirav high-risk clinic, Sheba Medical center, Israel were eligible. Type and frequencies if use of Imaging modalities, breast biopsies and histological outcomes for participants after age 70 years were retrieved and analyzed. RESULTS: Overall, the study encompassed 88 consenting participants (46 BRCA1 carriers) mean age ± SD 73.7 ± 3.3 years (range 70-90 years), followed for an average of 3.8 years (range 1-11 years). Ten carriers (11.3%) were diagnosed with BC after age 70 years (mean age at diagnosis 72 ± 2 years) and an additional case was diagnosed with breast lymphoma. The imaging modality that has led to most diagnoses was MRI (8/11 cases). Eight of these ten cases were previously diagnosed with BC prior to age 70 and in six, BC past 70 years was in the contralateral breast. The lesions size averaged 1.29 ± 0.75 cm, with IDC and DCIS diagnosed in five cases each, and none had lymph node involvement. CONCLUSION: In ~10% of BRCA1/BRCA2 PSV carriers BC is diagnosed by breast imaging after age 70 years. If these results are validated in a larger study, the guidelines for the maximum age for BC surveillance in high risk women should be revisited and set at 75 years.

Spectrum of germline pathogenic variants in Brazilian hereditary breast/ovarian cancer cases.

PURPOSE: To define the spectrum of germline pathogenic variants (PVs) and copy number variant (CNV) in cancer susceptibility genes to the burden of breast and ovarian cancer (BC, OvC) in high-risk Brazilians in Minas Gerais with health insurance, southeast Brazil, undergoing multigene panel testing (MGPT). METHODS: Genotyping eligible individuals with health insurance in the Brazilian healthcare system for Hereditary Breast and Ovarian Cancer Syndrome to undergo molecular testing for 44 or 141-gene panels, a decision that was insurance driven. RESULTS: Overall, 701 individuals clinically defined as high BC/OvC risk, underwent MGPT from 1/2021 to 10/2022, with ~ 50% genotyped with a 44-gene panel and the rest with a 141-gene panel. Overall, 16.4% and 22.6% of genotyped individuals harbored PVs using 44-gene and the 141 gene panel, respectively. The most frequently mutated genes were: BRCA2 (3.7%); BRCA1 (3.6%) and monoallelic MUTYH (3.1%). CONCLUSION: The rate of PVs detected in high-risk individuals in this study was twice the 10% threshold used in Brazilian health guidelines. MGPT doubled the detection rate of PVs in cancer susceptibility genes in high-risk individuals compared with BRCA1/BRCA2 genotyping alone. The spectrum of PVs in Southern Brazil is diverse, with few recurring variants such as TP53 (0.6%), suggesting regional founder effects. The use of MGPT in hereditary cancer in Minas Gerais significantly increased the detection rate of P/LPVs compared to existing guidelines and should be considered as the primary genotyping modality in assessing hereditary cancer risk in Brazil.

Obesity and adverse breast cancer risk and outcome: Mechanistic insights and strategies for intervention.

Answer questions and earn CME/CNE Recent decades have seen an unprecedented rise in obesity, and the health impact thereof is increasingly evident. In 2014, worldwide, more than 1.9 billion adults were overweight (body mass index [BMI], 25-29.9 kg/m2 ), and of these, over 600 million were obese (BMI ≥30 kg/m2 ). Although the association between obesity and the risk of diabetes and coronary artery disease is widely known, the impact of obesity on cancer incidence, morbidity, and mortality is not fully appreciated. Obesity is associated both with a higher risk of developing breast cancer, particularly in postmenopausal women, and with worse disease outcome for women of all ages. The first part of this review summarizes the relationships between obesity and breast cancer development and outcomes in premenopausal and postmenopausal women and in those with hormone receptor-positive and -negative disease. The second part of this review addresses hypothesized molecular mechanistic insights that may underlie the effects of obesity to increase local and circulating proinflammatory cytokines, promote tumor angiogenesis and stimulate the most malignant cancer stem cell population to drive cancer growth, invasion, and metastasis. Finally, a review of observational studies demonstrates that increased physical activity is associated with lower breast cancer risk and better outcomes. The effects of recent lifestyle interventions to decrease sex steroids, insulin/insulin-like growth factor-1 pathway activation, and inflammatory biomarkers associated with worse breast cancer outcomes in obesity also are discussed. Although many observational studies indicate that exercise with weight loss is associated with improved breast cancer outcome, further prospective studies are needed to determine whether weight reduction will lead to improved patient outcomes. It is hoped that several ongoing lifestyle intervention trials, which are reviewed herein, will support the systematic incorporation of weight loss intervention strategies into care for patients with breast cancer. CA Cancer J Clin 2017;67:378-397. © 2017 American Cancer Society.

Bilateral Peters' anomaly, aniridia and Wilms tumour (WAGR syndrome) in monozygotic twins.

AIM: This study reports the bilateral association of Peters' anomaly and congenital aniridia in monozygotic twins subsequently diagnosed with Wilms tumour (WAGR syndrome). METHODS: Two monozygotic female twins were referred at age 2 months with bilateral corneal opacity. A diagnosis of Peters' anomaly associated to aniridia was made in both eyes of both twins. Physical examination and ultrasonography were carried out at 12 months of age to explore the possibility of WAGR-related anomalies, specifically Wilms tumour. DNA were isolated and subjected to whole exome sequencing. RESULTS: Peters' anomaly associated to aniridia in both eyes as well as bilateral Wilms tumour in both children were diagnosed. Exome analyses showed a large heterozygous deletion encompassing 6 648 473 bp in chromosome 11p13, using Integrative Genomics Viewer and AnnotSV software. CONCLUSION: WAGR syndrome is a rare contiguous gene deletion syndrome with a greater risk of developing Wilms tumour associated with Peters' anomaly and congenital aniridia. However, co-occurrence of both anomalies was rarely reported in twins, and never in both eyes of monozygotic twins. Here, we report the bilateral association of Peters' anomaly and congenital aniridia in monozygotic twins with WAGR syndrome.

Proteomic signature for detection of high-grade ovarian cancer in germline BRCA mutation carriers.

No current screening methods for high-grade ovarian cancer (HGOC) guarantee effective early detection for high-risk women such as germline BRCA mutation carriers. Therefore, the standard-of-care remains risk-reducing salpingo-oophorectomy (RRSO) around age 40. Proximal liquid biopsy is a promising source of biomarkers, but sensitivity has not yet qualified for clinical implementation. We aimed to develop a proteomic assay based on proximal liquid biopsy, as a decision support tool for monitoring high-risk population. Ninety Israeli BRCA1 or BRCA2 mutation carriers were included in the training set (17 HGOC patients and 73 asymptomatic women), (BEDOCA trial; ClinicalTrials.gov Identifier: NCT03150121). The proteome of the microvesicle fraction of the samples was profiled by mass spectrometry and a classifier was developed using logistic regression. An independent cohort of 98 BRCA mutation carriers was used for validation. Safety information was collected for all women who opted for uterine lavage in a clinic setting. We present a 7-protein diagnostic signature, with AUC >0.97 and a negative predictive value (NPV) of 100% for detecting HGOC. The AUC of the biomarker in the independent validation set was >0.94 and the NPV >99%. The sampling procedure was clinically acceptable, with favorable pain scores and safety. We conclude that the acquisition of Müllerian tract proximal liquid biopsies in women at high-risk for HGOC and the application of the BRCA-specific diagnostic assay demonstrates high sensitivity, specificity, technical feasibility and safety. Similar classifier for an average-risk population is warranted.

Variations in Practice and Geographic Disparities Between Dedicated Multidisciplinary Clinics for BRCA1/BRCA2 Mutation Carriers in Israel.

BACKGROUND: Population screening for the BRCA mutations in Ashkenazi Jewish women was recently implemented in Israel and is expected to lead to a 10-fold increase in the diagnosis of asymptomatic carriers. Performing the screening follow-up within multidisciplinary dedicated clinics for carriers is recommended for early detection and risk reduction. OBJECTIVES: : To determine the availability, capacity, and practices of dedicated screening clinic for BRCA carriers in Israel. METHODS: A telephone-based survey of all public hospitals in Israel was conducted October 2020 to August 2021 to determine whether they had a dedicated clinic. Dedicated clinics were defined as multidisciplinary screening clinics offering at least breast and gynecological screening and risk reducing services on site. The clinic director or nurse navigator answered a questionnaire about screening practices followed by a semi-structured interview. RESULTS: Of the ten dedicated BRCA clinics found in Israel, nine participated. Approximately 4500 BRCA carriers are currently being followed. No specialized clinics are available in the southern district or in the northernmost half of the northern district of Israel, leading to a disparity between periphery and center. Screening recommendations, although asserted as adhering to international guidelines, vary among clinics including age at initiating of clinical exam, use of adjunct imaging modalities, and follow-up during lactation and after risk reducing surgery. CONCLUSIONS: There is a suboptimal distribution of dedicated clinics for BRCA carriers in Israel. Nationally centralized attempt to create guidelines that will unify screening practices is warranted, especially considering the expected increase in demand.

[GENOTYPE-PHENOTYPE CORRELATIONS BY SPECIFIC FOUNDER VARIANTS IN BRCA IN ISRAELI WOMEN].

INTRODUCTION: Hereditary breast and ovarian cancer (HBOC) is predominantly accounted for by pathogenic variants (PVs) in BRCA1/BRCA2 genes. Population screening for recurring PVs in Ashkenazi Jews (AJ) was incorporated into the Israeli health basket in 2020, increasing the identification of BRCA carriers. Information on cancer risks for each PV in Israel is limited. AIMS: To assess genotype phenotype correlations of recurring BRCA PVs in Israeli carriers. METHODS: A retrospective cohort of 3,478 BRCA carriers followed-up in 12 medical centers, comprising the HBOC Consortium, formed the basis of the study. Data were collected using the electronic database, and analyzed by Chi square, t-tests and Kaplan-Meier survival analysis. RESULTS: Overall, 2145 BRCA1, 1131 BRCA2, and 22 double heterozygote PV carriers were analyzed. BRCA1 carriers had more cases of cancer (53.1% vs. 44.8%, p<0.001), ovarian cancer (OC) (17.1% vs. 10.6%, p<0.001), younger age at breast cancer (BC) (45.4 ±11.6SD years vs. 49.1 ±11.1SD years, p<0.001) and OC diagnosis (52.8 ±10.1SD yrs. vs. 61±10.6SD yrs. p<0.001), and more family history of BC (64.5% vs. 59.0%, p<0.001) and OC (36.7% vs. 27.3%, p<0.001) compared with BRCA2 carriers. Carriers of BRCA15382insC had more BC and less OC than BRCA1185delAG: 46.4% vs. 38.6% and 12.9% vs. 17.6% (p<0.04), respectively. CONCLUSIONS: In our population, similar to others, BRCA1 carriers have higher cancer rates and earlier age at diagnosis compared with BRCA2 carriers. The two recurring BRCA1 PVs have different risks: 5382insC carriers had more BC; 185delAG carriers had more OC. Risk-reducing measures should be based on variant-specific cancer risk.

Cancer risks associated with heterozygous ATM loss of function and missense pathogenic variants based on multigene panel analysis.

PURPOSE: Cancer risks conferred by germline, heterozygous, ATM pathogenic/likely pathogenic variants (PSVs) are yet to be consistently determined. The current study assessed these risks by analysis of a large dataset of ATM heterozygote loss of function (LOF) and missense PSV carriers tested with a multigene panel (MGP). METHODS: De-identified data of all individuals who underwent ATM sequencing as part of MGP between October 2015 and February 2020 were reviewed. In cancer cases, rates for the six most prevalent variants and for all LOF and missense PSV combined were compared with rates of the same PSV in ethnically matched, healthy population controls. Statistical analysis included Chi-square tests and odds ratios calculations. RESULTS: For female breast cancer cases, LOF )1794/219,269) and missense (301/219,269) ATM PSVs were seen at higher rates compared to gnomAD non-cancer controls (n = 157/56,001 and n = 27/61,208; p < 0.00001, respectively). Notably, the rate of the c.103C > T variant was higher in controls than in breast cancer cases [p = 0.001; OR 0.31 (95% CI 0.1-0.6)]. For all cancer cases combined, compared with non-cancer population controls, LOF (n = 143) and missense (n = 15) PSVs reported in both datasets were significantly more prevalent in cancer cases [ORLOF 1.7 (95% 1.5-1.9) ORmissense 3.0 (95% CI 2.3-4); p = 0.0001]. CONCLUSION: Both LOF and missense heterozygous ATM PSVs are more frequently detected in cases of several cancer types (breast, ovarian, prostate, lung, pancreatic) compared with healthy population controls. However, not all ATM PSVs confer an increased cancer risk (e.g., breast).

Divergence of mutational signatures in association with breast cancer subtype.

Abnormal molecular processes occurring throughout the genome leave distinct somatic mutational patterns termed mutational signatures. Exploring the associations between mutational signatures and clinicopathological features can unravel potential mechanisms driving tumorigenic processes. We analyzed whole genome sequencing (WGS) data of tumor and peripheral blood samples from 37 primary breast cancer (BC) patients receiving neoadjuvant chemotherapy. Comprehensive clinico-pathologic features were correlated with genomic profiles and mutational signatures. Somatic mutational landscapes were highly concordant with known BC data sets. Remarkably, we observed a divergence of dominant mutational signatures in association with BC subtype. Signature 5 was overrepresented in hormone receptor positive (HR+) patients, whereas triple-negative tumors mostly lacked Signature 5, but expectedly overrepresented Signature 3. We validated these findings in a large WGS data set of BC, demonstrating dominance of Signature 5 in HR+ patients, mostly in luminal A subtype. We further investigated the association between Signature 5 and gene expression signatures, and identified potential networks, likely related to estrogen regulation. Our results suggest that the yet elusive Signature 5 represents an alternative mechanism for mutation accumulation in HR+ BC, independent of the homologous recombination repair machinery related to Signature 3. This study provides theoretical basis for further elucidating the processes promoting hormonal breast carcinogenesis.

Secondary cancer after meningioma diagnosis: an Israeli national study.

BACKGROUND: There are limited data on whether primary diagnosis of meningioma may be associated with development of secondary primary cancer (SPC). METHODS: All meningioma cases (ICD-O-3 morphology codes 9530/0-9539/3) diagnosed in Jewish Israelis ≥ 20 years 1990 through 2015 registered in the Israel National Cancer Registry (INCR) were retrieved. All subsequent cancers occurring more than 6 months after meningioma diagnosis were identified. Risk of secondary cancer (SPC) was compared to cancer risk in the general population through the calculation of standardized incidence ratios (SIRs) and excess absolute risks (EARs). SIRs were stratified by type of second cancer, sex, and age group. Cox regression models were used to estimate hazard ratios of developing SPC. RESULTS: Overall, 8044 meningioma cases were identified: mean age at diagnosis was 64.0 ± 14.1 years. Of these, 927 (11.5%) were diagnosed with SPC (SIR 1.6, 95% CI 1.5-1.7). SPC risk was elevated in men (SIR 1.6, 95% CI 1.5-1.9) and women (SIR 1.6, 95% CI 1.5-1.8) diagnosed with meningioma in univariable analyses. Cancers most commonly encountered in the studied population were breast (17.6%), colorectal (13.4%), lung (8.1%), prostate (5%), and bladder (4.6%) cancer. In multivariable analyses, 10+ year increment in age at meningioma diagnosis was significantly associated with higher risk for SPC in individuals diagnosed with meningioma between 20 and 64 years, with an inverse association in the older age group (65+ years). CONCLUSIONS: Meningioma diagnosis is associated with an increased risk for developing secondary cancers. This risk should be discussed with patients treated for meningioma.

The risks of breast and ovarian cancer associated with the Ashkenazi Jewish founder allele BRCA2 6174delT.

Approximately 1% of the Ashkenazi Jewish population carries the BRCA2 6174delT (c.5946del) pathogenic variant. It is important to have accurate knowledge of the risks of breast and ovarian cancer associated with this specific variant so that women may be counseled accordingly. In this prospective study, we estimated the risks of breast and ovarian cancer associated with the 6174delT variant compared with the risks for other pathogenic variants in the BRCA2 gene. The annual risk for developing breast cancer was significantly lower in 246 women who carried the 6174delT variant compared with 721 non-Jewish women who carried a variant at any other locus in BRCA2 (1.2% per year vs. 2.4% per year, p = 0.003). We estimated the cumulative risk of breast cancer from age 30 to 70 to be 39% for carriers of the BRCA2 6174delT variant and 61% for carriers of other BRCA2 variants. The annual risk for ovarian or fallopian tube cancer was 0.51% per year for the 233 women who carried the 6174delT variant compared to 0.22% per year for the 1128 carriers of other BRCA2 variants; the difference was not significant. Lower risks for breast cancer associated with 6174delT may not impact screening and prevention choices, however, the discussion should be based on accurate risk assessment.

Polygenic risk scores indicate extreme ages at onset of breast cancer in female BRCA1/2 pathogenic variant carriers.

BACKGROUND: Clinical management of women carrying a germline pathogenic variant (PV) in the BRCA1/2 genes demands for accurate age-dependent estimators of breast cancer (BC) risks, which were found to be affected by a variety of intrinsic and extrinsic factors. Here we assess the contribution of polygenic risk scores (PRSs) to the occurrence of extreme phenotypes with respect to age at onset, namely, primary BC diagnosis before the age of 35 years (early diagnosis, ED) and cancer-free survival until the age of 60 years (late/no diagnosis, LD) in female BRCA1/2 PV carriers. METHODS: Overall, estrogen receptor (ER)-positive, and ER-negative BC PRSs as developed by Kuchenbaecker et al. for BC risk discrimination in female BRCA1/2 PV carriers were employed for PRS computation in a curated sample of 295 women of European descent carrying PVs in the BRCA1 (n=183) or the BRCA2 gene (n=112), and did either fulfill the ED criteria (n=162, mean age at diagnosis: 28.3 years, range: 20 to 34 years) or the LD criteria (n=133). Binomial logistic regression was applied to assess the association of standardized PRSs with either ED or LD under adjustment for patient recruitment criteria for germline testing and localization of BRCA1/2 PVs in the corresponding BC or ovarian cancer (OC) cluster regions. RESULTS: For BRCA1 PV carriers, the standardized overall BC PRS displayed the strongest association with ED (odds ratio (OR) = 1.62; 95% confidence interval (CI): 1.16-2.31, p<0.01). Additionally, statistically significant associations of selection for the patient recruitment criteria for germline testing and localization of pathogenic PVs outside the BRCA1 OC cluster region with ED were observed. For BRCA2 PV carriers, the standardized PRS for ER-negative BC displayed the strongest association (OR = 2.27, 95% CI: 1.45-3.78, p<0.001). CONCLUSIONS: PRSs contribute to the development of extreme phenotypes of female BRCA1/2 PV carriers with respect to age at primary BC diagnosis. Construction of optimized PRS SNP sets for BC risk stratification in BRCA1/2 PV carriers should be the task of future studies with larger, well-defined study samples. Furthermore, our results provide further evidence, that localization of PVs in BC/OC cluster regions might be considered in BC risk calculations for unaffected BRCA1/2 PV carriers.

Ductal Carcinoma In Situ (DCIS) Diagnosed by MRI-Guided Biopsy among BRCA1/BRCA2 Mutation Carriers.

Background: While BRCA1/BRCA2 pathogenic sequence variants (PSVs) clearly confer an increased risk for invasive breast cancer, the extent to which these mutant alleles increase DCIS risk is less clear. Objective: To assess the rate of detection over a 5-year period, and MRI imaging features of pure noncalcified DCIS in a cohort of Israeli BRCA1/BRCA2 PSV carriers attending a high-risk clinic from 2015 to 2020. Materials and Methods: All female BRCA1/BRCA2 PSV-carriers followed at the Meirav High-risk clinic from 2015 to 2020 were eligible if they underwent semiannual breast imaging (MRI/mammography) and MRI-guided biopsy-proven pure DCIS. Clinical data, pathology information, and imaging characteristics were retrieved from the computerized archiving system. Results: 18/121 (15.2%) participating BRCA1 PSV carriers and 8/81 (10.1%) BRCA2 PSV-carriers who underwent MRI-guided biopsy were diagnosed with DCIS. The median age of BRCA1 carriers and BRCA2 carriers was 49.8 years and 60.6 years, respectively (p = 0.55). Negative estrogen-receptor tumors were diagnosed in 13/18 (72%) BRCA1 and 2/8 (25%) BRCA2 PSV carriers (p < 0.05). Thirteen (13/18-72%) BRCA1 carriers had intermediate to high-grade or high-grade DCIS compared with 4/8 (50%) of BRCA2 carriers (p = 0.03). Over the 5-year study period, 29/1100 (2.6%) BRCA1/BRCA2 PSV carriers were diagnosed with DCIS seen on MRI only. Conclusion: MRI-detected noncalcified DCIS is more frequent in BRCA1 PSV carriers compared with BRCA2 carriers, unlike the BRCA2 predominance in mammography-detected calcified DCIS. BRCA1-related DCIS is diagnosed earlier, more likely to be estrogen receptor-negative and of higher grade compared with BRCA2-related DCIS. Future prospective studies should validate these results and assess the actual impact they might have on clinical management of BRCA PSV carriers.

Re-evaluating the pathogenicity of the c.783+2T>C BAP1 germline variant.

BAP1 germline pathogenic sequence variants (PSVs) underlie a unique tumor predisposition syndrome (BAP1-TPDS) associated with an increased lifetime risk for developing primarily pleural and peritoneal mesothelioma and uveal and cutaneous melanoma. Overwhelmingly, BAP1 PSVs are unique, family-specific inactivating variants. We identified seven families, six of Jewish Iraqi origin, harboring an identical BAP1 splice variant (c.783+2T>C), currently assigned a "likely pathogenic" status. Given a nonclassical BAP1-TPDS tumor type clustering and low penetrance in these families, the pathogenicity of this variant was re-evaluated by a combined approach including literature analysis, revised bioinformatics analysis, allelic loss, effect on the transcript, and tumor protein expression patterns. None of the three available tumors showed an allelic loss, there was no discernable effect on alternative splicing based on reverse-transcription polymerase chain reaction, and there was no decrease or loss of somatic protein expression in 2/3 analyzed tumors. This led to assigning a Benign Strong (BS) criteria, BS4, supporting BS3 criteria, and weakening the Pathogenic Supporting (PP) criteria PP5. Combined, these data suggest that this sequence variant should be reclassified as a variant of unknown significance by American College of Medical Genetics (ACMG) criteria.

Yield of targeted genotyping for the recurring pathogenic variants in cancer susceptibility genes in a healthy, multiethnic Israeli population.

BACKGROUND: Several recurring pathogenic variants in BRCA1/BRCA2 and other cancer susceptibility genes are encountered in ethnically diverse Jewish populations. The yield of genotyping for these recurring pathogenic variants in healthy Israeli individuals unselected for ethnicity, sex, or a family history of cancer has not been previously reported. METHODS: Individuals voluntarily participating in annual medical surveillance at the Institute of Medical Screening of Sheba Medical Center were offered genotyping for predominant pathogenic variants in BRCA1/BRCA2 and recurring variants in CHEK2, MUTYH, APC, and the Lynch syndrome genes via a chip-based assay at the oncogenetic service of Sheba Medical Center from May 15, 2018, to December 15, 2020. All study participants were unrelated to one another. The study was approved by the Sheba ethics committee. RESULTS: Overall, 1764 individuals, including 1008 females (57%), with a mean age of 54.2 years (range, 25-86 years) were genotyped. The yield of the testing was 4% (71 of 1764), and it was higher in Ashkenazi Jews (AJs) and mixed AJ-non-AJ participants (4.75% [58 of 1222]; 1.8% for BRCA1/BRCA2 pathogenic variants) than non-AJ patients (2.2% [9 of 401]; 1% for BRCA1 pathogenic variants). When BRCA1/BRCA2 pathogenic variants were excluded, 2.44% carried low-penetrance variants, including CHEK2 c.1283C>T (n = 3), APC c.3920T>A (n = 36), and heterozygous MUTYH c.1187G>A (n = 4). A family history of cancer was not associated with a higher yield of pathogenic variant detection. CONCLUSIONS: The observed rates of positive genotyping in a healthy, unselected, multiethnic Israeli population warrant consideration of the inclusion of targeted genotyping of selected pathogenic variants in high-penetrance and perhaps lower penetrance cancer susceptibility genes for all Jewish individuals in Israel, regardless of their ethnicity or family history of cancer.

Double heterozygosity for TP53 and BRCA1 mutations: clinical implications in populations with founder mutations.

PURPOSE: The co-occurrence or double heterozygosity of pathogenic/likely pathogenic sequence variants (P/LPSVs) in major cancer susceptibility genes has rarely been reported. Such co-occurrence raises the issues of accurate genetic counseling, preferred recommended surveillance scheme, and the use of preimplantation genetic diagnosis (PGD). METHODS: A clinical report of an Ashkenazi Jewish (AJ) family with co occurrence of two PSVs in BRCA1 and TP53 and a literature search. RESULTS: In an AJ family with a substantial history of cancer limited to the maternal side, two siblings co-harbored TP53 (c.733C>A; p.G245S) and the predominant 5266dup BRCA1 mutation, originating from the mother and the father, respectively. PGD is ongoing. Four families were thus far reported as double heterozygotes for both BRCA1/BRCA2 and TP53. Based on the limited available data, it seems that the phenotype in double PSV heterozygotes is not more severe than in single PSV carrier in either gene. CONCLUSIONS: This family highlights the need to genotype both parents, especially in populations with founder mutations, when a BRCA1 mutation is detected in an offspring, regardless of family history. The combination of mutations in these two genes presents a challenge for PGD since both genes are located on chromosome 17.

Time trends in uptake rates of risk-reducing mastectomy in Israeli asymptomatic BRCA1 and BRCA2 mutation carriers.

BACKGROUND: The rate of risk-reducing bilateral mastectomy (RRBM) among cancer-free Israeli female BRCA1/BRCA2 mutation carriers was reportedly 13% in 2010. Current RRBM rates in Israel and factors seemingly associated with opting for RRBM were reevaluated. METHODS: Israeli female cancer-free BRCA1/BRCA2 mutation carriers, who were followed at the high-risk clinic at Sheba Medical Center between January 2011 and April 2020 were eligible. Univariate Cox regression and log-rank test were used to study the crude association between potential predictors and performance of RRBM. RESULTS: Overall, 427 cancer-free BRCA1 (n = 218) or BRCA2 (n = 209) mutation carriers were included. Median age at genotyping was 33.6 years (interquartile range 26.8-41.8 years), median follow-up 4.4 years (range 0.1-7.6 years). Overall, 41/427 (9.6%) participants underwent RRBM, all of them within 5 years of genotyping. Being married (HR-2.57, p = 0.017) and having a first degree relative with breast cancer (BC) (HR-2.19, p = 0.017) were positively associated with RRBM, whereas any previous benign breast biopsy was negatively associated (HR-0.48, p = 0.029) with performing RRBM. CONCLUSIONS: RRBM is still infrequently elected by Israeli BRCA1/BRCA2 mutation carriers, with married women with one relative with BC who have not undergone previous breast biopsy more likely to opt for RRBM.

Double heterozygotes of BRCA1/BRCA2 and mismatch repair gene pathogenic variants: case series and clinical implications.

BACKGROUND: Hereditary breast and ovarian cancer syndrome (HBOC) and Lynch syndrome (LS), the most common inherited cancer syndromes, are attributed to a single heterozygous pathogenic variant (PV) in BRCA1/2 or in a DNA MMR gene, respectively. Little is known about the phenotype in double heterozygotes who carry PVs in both genes. METHODS: Carriers of double-PVs in any DNA MMR gene and BRCA1/2 attending one of three tertiary oncogenetic clinics between 1/2005 and 1/2020 were identified by database search, and their relevant data were retrieved and analyzed. RESULTS: Eleven double carriers from four seemingly unrelated Ashkenazi Jewish families were evaluated. All carried an Ashkenazi Jewish founder BRCA PV, BRCA2 c.5946delT/c.6174delT (n = 10) or BRCA1 c.185delAG (n = 1). Four carried the MSH2 c.1906G > C founder PV, and 3, the MSH6 c.3984_3987dupGTCA founder PV; 3 patients had the MSH6 c.3956_3957dup PV. Eight double carriers (73%) had cancer: breast cancer (5 cases, 2 bilateral), melanoma (2 cases), urothelial cancer (2 cases), and colon, endometrial, prostate, cutaneous squamous cell cancer, glioblastoma, gastric stromal tumor, and lymphoma (1 case each). Six carriers had 1-2 tumors, one had 3 tumors, and one had 5 primary tumors. Age at diagnosis of the first tumor was 36-76 years. All carriers met NCCN BRCA1/2 testing criteria, and 3 met the revised Bethesda guidelines. CONCLUSIONS: This case series, supported by the literature, suggests that the phenotype of double MSH2/6 and BRCA1/2 carriers is not associated with early disease onset or a more severe phenotype. The findings have implications for improved genetic testing guidelines and treatment strategies.