BRCA1 Pathogenic Variant Carriers Research Articles

Abstract PS10-01: Hormonal Contraception and Breast Cancer Risk for Carriers of Germline Pathogenic Variants in BRCA1 and BRCA2

Abstract BACKGROUND: Current use of hormonal contraception is associated with a 20-30% relative increase in the risk of breast cancer (BC) for women in the general population compared with never using. Longer duration of use is associated with higher risk, and the risk remains elevated above that of never users for at least 5 years after cessation. Most published data are for various formulations of the combined oral contraceptive pill, but associations are similar for progestogen-only contraceptives, including intrauterine devices. For women in the general population who use hormonal contraceptives in their 20s and 30s, when baseline BC risk for most women is low, these increased relative risks translate into only small increases in absolute risk. It is unclear whether use of hormonal contraceptives increases BC risk for women carrying a germline BRCA1 or BRCA2 pathogenic variant (PV). These women are at markedly higher risk of early-onset BC, so even slightly increased relative risks could translate to important increases in their absolute risk of BC. This study assessed the association between use of any hormonal contraception and BC risk for BRCA1 and BRCA2 PV carriers using individual participant data from four prospective cohorts. METHODS: Data from females born after 1920 with a PV in BRCA1 or BRCA2 and no history of cancer or bilateral mastectomy at cohort entry were analyzed. Cox regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for BC (invasive disease or ductal carcinoma in situ) associated with use of hormonal contraceptives for at least 1 year, with age as the timescale, entry at cohort enrolment, and censoring at the earlier of bilateral mastectomy, death, diagnosis of another cancer or last follow-up. Analyses were adjusted for study, birth cohort, first-degree family history of BC, parity, premenopausal bilateral oophorectomy and menopausal status. Current use of hormonal contraceptives was defined as use within the previous year, to account for cessation of use due to BC symptoms or clinical investigation. RESULTS: Of 3,882 BRCA1 and 1,509 BRCA2 PV carriers, 53% and 71%, respectively had ever used hormonal contraceptives (for at least one year). The median cumulative duration of hormonal contraceptive use was 4.8 and 5.7 years, respectively. Overall, 488 BRCA1 and 191 BRCA2 PV carriers developed incident BC during a median of 5.9 and 5.6 years of follow-up, respectively. For BRCA1 PV carriers, use of hormonal contraceptives for at least 1 year was associated with increased BC risk (HR [95% CI]: 1.29 [1.04-1.60] p=0.019). BC risk increased with longer cumulative duration of hormonal contraceptive use (HR [95% CI]: 1.13 [0.88-1.45] p=0.35, 1.48 [1.11-1.96] p=0.007 and 1.56 [1.13-2.17] p=0.007 for 1-5, 6-10 and >10 years of use, respectively), with an estimated proportional increase in risk of 3% (1%-5%, p=0.002) for each additional year of use. For BRCA2 PV carriers, there was no evidence that current or past use, or cumulative duration of use, were associated with increased risk of BC, but confidence intervals on the HRs were wide. CONCLUSION: Hormonal contraceptive use is associated with an increased risk of BC for women carrying PVs in BRCA1 and risk increases with cumulative duration of use. Hormonal contraceptives are an important healthcare option for women; they provide excellent contraceptive efficacy and reduce risks of ovarian and endometrial cancer. Decisions about use of hormonal contraceptives in women at increased risk for BC due to BRCA1 PVs need to carefully weigh the risks and benefits; while shorter-term use may result in only small increases, prolonged cumulative use may result in larger increases in absolute BC risk that may not be acceptable to some women. Citation Format: Kelly-Anne Phillips, Joanne Kotsopoulos, Susan Domchek, James Chamberlain, Julie Bassett, Amber Aeilts, Irene Andrulis, Saundra Buys, Wanda Cui, Mary Daly, Andrea Eisen, William Foulkes, Michael Friedlander, Jacek Gronwald, John Hopper, Esther John, Beth Karlan, Raymond Kim, Jan Lubiński, Kelly Metcalfe, Katherine Nathanson, Christian F. Singer, Heather Symecko, Nadine Tung, Steven Narod, Mary Beth Terry, Roger Milne. Hormonal Contraception and Breast Cancer Risk for Carriers of Germline Pathogenic Variants in BRCA1 and BRCA2 [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 PS10-01.

Abstract P70: HIGH-THROUGHPUT IMAGING-BASED PHENOTYPIC PROFILING OF IMMUNE CELLS FROM BRCA2 VARIANT CARRIERS AND NON-CARRIERS

Abstract Mutated germline alleles in the DNA damage repair (DDR) genes BRCA1/2 are major risk factors for breast and ovarian cancers. Recent studies have found that BRCA1-mutant tumors tend to have higher abundance of immune cells within the tumor microenvironment, but much better response was observed from the BRCA2-mutant tumors when given immune-checkpoint inhibitors, suggesting possible functional and phenotypic effects of germline BRCA2 mutations on the immune cells. However, most existing studies focus on investigating the genomic instability and phenotypes of hereditary mutations in breast and ovarian cancer cells. Thus, the impact of these mutations on immune cells’ phenotypes and functions remains largely unknown. Here, we report a study of immune cells with and without BRCA2 mutations using High-throughput Imaging-based Phenotypic Profiling (HIPP), which can identify changes in cellular morphology and protein subcellular localization patterns that are not obvious from other traditional functional assays. We performed HIPP on immune cells from nine BRCA2 pathogenic variant carriers and eight non-carriers. Automatic quantification of ~200 phenotypic features from each single cell revealed that CD8+ T cells from BRCA2 variant carriers have distinct and quantifiable changes in their morphological features (such as cytoskeleton structures) and immunological features (such as Granzyme B expressions). Moreover, we found that BRCA2-mutant CD8+ T cells proliferate faster than normal CD8+ T cells. Our results suggest that BRCA2 mutations affect the functions and phenotypes of immune cells. Some of these phenotypic features and markers may be used to classify BRCA2 variants and predict the pathogenicity of variants of uncertain significance (VUS). Our study provides new insight into the immune phenotyping of cancer patients at individual level and may help to stratify patients, leading to the development of more effective therapeutic strategies. This method can potentially extend to other germline variants and overcome the challenge of VUS interpretation in clinical management. Citation Format: Guorui Zhong, Oscar Fu, Claresta Yeo, Siao Ting Chong, Sock Hoai Chan, Joanne Ngeow, Lit-Hsin Loo. HIGH-THROUGHPUT IMAGING-BASED PHENOTYPIC PROFILING OF IMMUNE CELLS FROM BRCA2 VARIANT CARRIERS AND NON-CARRIERS [abstract]. In: Proceedings of Frontiers in Cancer Science; 2023 Nov 6-8; Singapore. Philadelphia (PA): AACR; Cancer Res 2024;84(8_Suppl):Abstract nr P70.

Ovarian cancer pathology characteristics as predictors of variant pathogenicity in BRCA1 and BRCA2

BackgroundThe distribution of ovarian tumour characteristics differs between germline BRCA1 and BRCA2 pathogenic variant carriers and non-carriers. In this study, we assessed the utility of ovarian tumour characteristics as predictors of BRCA1 and BRCA2 variant pathogenicity, for application using the American College of Medical Genetics and the Association for Molecular Pathology (ACMG/AMP) variant classification system.MethodsData for 10,373 ovarian cancer cases, including carriers and non-carriers of BRCA1 or BRCA2 pathogenic variants, were collected from unpublished international cohorts and consortia and published studies. Likelihood ratios (LR) were calculated for the association of ovarian cancer histology and other characteristics, with BRCA1 and BRCA2 variant pathogenicity. Estimates were aligned to ACMG/AMP code strengths (supporting, moderate, strong).ResultsNo histological subtype provided informative ACMG/AMP evidence in favour of BRCA1 and BRCA2 variant pathogenicity. Evidence against variant pathogenicity was estimated for the mucinous and clear cell histologies (supporting) and borderline cases (moderate). Refined associations are provided according to tumour grade, invasion and age at diagnosis.ConclusionsWe provide detailed estimates for predicting BRCA1 and BRCA2 variant pathogenicity based on ovarian tumour characteristics. This evidence can be combined with other variant information under the ACMG/AMP classification system, to improve classification and carrier clinical management.

COVID-19 vaccination uptake and safety profile among germline BRCA1 and BRCA2 pathogenic variant carriers in Singapore

BackgroundAlthough Singapore is one of the highest vaccinated countries in the world, vaccine hesitancy remains in a subpopulation, including individuals with cancer predisposition syndromes. At the Cancer Genetics Service National Cancer Centre Singapore, we see patients with germline genetic alterations, most being BRCA1/2 pathogenic/likely pathogenic variant (PV/LPV) carriers. While reported safe for cancer patients, there are limited studies addressing the safety profile and outcomes of COVID-19 vaccination among individuals with germline PV/LPV in cancer predisposition genes such as BRCA1/2. This study aims to evaluate the outcomes of COVID-19 vaccination among germline PV/LPV carriers in BRCA1/2.MethodsWe conducted a phone call survey of COVID-19 vaccination uptake and toxicity in a prospective cohort of 189 participants with germline BRCA1/2 PV/LPV between 1st Sept 2021 and 30th Sept 2021. We collected demographics data including gender, race, age, history of cancer, types of cancer, and number of cancers. Statistical difference in baseline demographics between responders with history of cancer and those without were assessed using Chi-square, Fisher’s exact and independent t-test analysis. Logistic regression was used to evaluate effect of demographics on the occurrence of post-vaccination side effects.ResultsAmong 189 BRCA1/2 PV/LPV carriers responded, 97 carried PV/LPV in BRCA1 and 92 in BRCA2. Majority were vaccinated (89.5%) and had completed the two-dose vaccine schedule, with 7 (4.1%) received only one dose. The most common post-vaccination side effects was myalgia (56.5%) followed by fever (40.2%), headache (16.3%) and fatigue (11.2%). There were no major severe side events. Evaluation by logistic regression showed that the occurrence of side effects was not affected by PV/LPV gene (BRCA1 or BRCA2), gender, race, age or history of cancer.ConclusionThe post-vaccination side effects profile among individuals with germline PV/LPV in BRCA1/2 is consistent with the Singaporean general population, hence recommendations for COVID-19 vaccination for these individuals should not differ from non-carriers and should be encouraged by their healthcare providers.

Abstract P5-03-15: Application of 21-gene Breast Recurrence Score® assay to evaluate prognosis and benefit of adjuvant chemotherapy in BRCA1 and BRCA2 pathogenic variant carriers with early stage, estrogen receptor positive breast cancer

Abstract Background: Minimal data exists for the utilization of the Oncotype Dx® assay specifically in breast cancers associated with BRCA1/2 pathogenic variants (PVs). It is unknown whether estrogen receptor positive (ER+) breast cancer associated with an inherited BRCA1 or BRCA2 (BRCA1/2) PV is more aggressive than disease seen in patients who do not carry an inherited PV, and whether there are differences between BRCA1 and BRCA2. In prostate cancer patients with inherited cancer predisposition due to a BRCA2 PV, more aggressive cancers are observed, which influences first-line treatment. Limited data exists for the optimal management of early stage ER+ breast cancer in BRCA1/2 PV carriers. Comparing Recurrence Score® (RS) results in ER+ breast cancer patients with an inherited BRCA1/2 PV (cases) versus matched patients who test negative for a PV in BRCA1/2 (controls) may inform whether biologically more aggressive breast cancer is seen in BRCA1/2 carriers and optimal treatment approaches. Methods: A retrospective case control study was performed to compare RS results in women with breast cancer with an inherited BRCA1/2 PV versus patients who tested negative for an inherited BRCA1/2 PV. Female breast cancer patients seen between 2005-2020 at NorthShore University Health System with ER+Her2- early stage invasive breast cancer with 0-3 lymph nodes who completed genetic testing for BRCA1/2 were eligible for enrollment. BRCA1/2 cases were defined as individuals with an inherited PV in BRCA1/2 and controls were negative for BRCA1/2 or other known breast cancer risk gene PVs tested. Subjects were excluded if they had neoadjuvant therapy (hormonal or cytotoxic chemotherapy). Eligible cases were matched to control patients by age, grade, and stage. The Recurrence Score result was obtained by chart review; if not previously evaluated, Oncotype Dx assay was performed by Exact Sciences. Statistical analysis of the primary outcome used the paired t-test to determine mean difference in RS results between BRCA1/2 PV carriers and patients negative for a PV in BRCA1/2 using a 1:1 matched pairs design. Results: A total of 46 matched cases and controls were analyzed. Median age was 50 with a range of 28-74. Of the cases, 18 had a BRCA1 PV and 28 had a BRCA2 PV. Cases and controls were well matched for age (> 50 and ≤ 50); race, grade, stage, and progesterone receptor status. As expected, a higher number of BRCA1/2 carriers were treated with mastectomy while more of the controls received breast-conserving surgery. Chemotherapy was utilized more frequently in the cases (67.4%) versus the controls (54.4%). The average RS result was higher in the cases (27) than the controls (21.3) by a mean difference of 5.7 (p = 0.0195). Using Oncotype Dx cutoffs of low < 18, intermediate 18-30 and high ≥ 31, a statistically significant difference in RS result was noted in the cases versus controls. For cases in the highest risk group (Oncotype Dx ≥ 31), only 20% of their matches also had a score in the highest risk group while 35% had a score in the lowest risk group. Subgroup analysis showed that the cases had the largest difference in RS result from their controls in premenopausal women (age ≤ 50), BRCA1 carriers, and the node negative population. Conclusion We present one of the largest data sets available to date of a well-matched cohort of cases and controls which shows that BRCA1/2 PV carriers are more likely to have a higher Recurrence Score result than their matched controls when matched for age, grade, and stage. These findings suggest ER+ breast cancer in BRCA1/2 PV carriers is biologically more aggressive. Further investigation is warranted to evaluate how this important finding impacts adjuvant therapy recommendations for BRCA1/2 PV carriers. Citation Format: Poornima Saha, Ashley Aller, Amanda Deliere, Peter Hulick, Katharine Yao, Kristine Kuchta, Megan Sullivan, Allison DePersia. Application of 21-gene Breast Recurrence Score® assay to evaluate prognosis and benefit of adjuvant chemotherapy in BRCA1 and BRCA2 pathogenic variant carriers with early stage, estrogen receptor positive breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-03-15.

Investigating the presentation of uncertainty in an icon array: A randomized trial

Clinicians are often advised to use pictographs to communicate risk, but whether they offer benefits when communicating risk imprecision (e.g., 65%-79%) is unknown. To test whether any of three approaches to visualizing imprecision would more effectively communicate breast and ovarian cancer risk for BRCA1 pathogenic variant carriers. 1,300 UK residents were presented with a genetic report with information about BRCA1-related risks, with random assignment to one of four formats: no visualization (text alone), or a pictograph using shaded icons, a gradient, or arrows marking range endpoints. We also tested pictographs in two layouts. Analysis of variance (ANOVA) and regression was employed. There was no effect of format. Participants shown pictographs vs. text alone had better uptake of breast cancer risk messages (p < .05, η 2 = 0.003). Pictographs facilitated memory for the specific amount of risk (p < 0.001, η 2 = 0.019), as did the tabular layout. Individuals not having completed upper secondary education may benefit most. We found weak evidence in favor of using simple pictographs with ranges to communicate BRCA risk (versus text alone), and of the tabular layout. Testing different ways of communicating imprecision within pictographs is a novel and promising line of research.

Association and performance of polygenic risk scores for breast cancer among French women presenting or not a familial predisposition to the disease

BackgroundThree partially overlapping breast cancer polygenic risk scores (PRS) comprising 77, 179 and 313 SNPs have been proposed for European-ancestry women by the Breast Cancer Association Consortium (BCAC) for improving risk prediction in the general population. However, the effect of these SNPs may vary from one country to another and within a country because of other factors. ObjectiveTo assess their associated risk and predictive performance in French women from (1) the CECILE population-based case-control study, (2) BRCA1 or BRCA2 (BRCA1/2) pathogenic variant (PV) carriers from the GEMO study, and (3) familial breast cancer cases with no BRCA1/2 PV and unrelated controls from the GENESIS study. ResultsAll three PRS were associated with breast cancer in all studies, with odds ratios per standard deviation varying from 1.7 to 2.0 in CECILE and GENESIS, and hazard ratios varying from 1.1 to 1.4 in GEMO. The predictive performance of PRS313 in CECILE was similar to that reported in BCAC but lower than that in GENESIS (area under the receiver operating characteristic curve (AUC) = 0.67 and 0.75, respectively). PRS were less performant in BRCA2 and BRCA1 PV carriers (AUC = 0.58 and 0.54 respectively). ConclusionOur results are in line with previous validation studies in the general population and in BRCA1/2 PV carriers. Additionally, we showed that PRS may be of clinical utility for women with a strong family history of breast cancer and no BRCA1/2 PV, and for those carrying a predicted PV in a moderate-risk gene like ATM, CHEK2 or PALB2.

Copy number variants as modifiers of breast cancer risk for BRCA1/BRCA2 pathogenic variant carriers

The contribution of germline copy number variants (CNVs) to risk of developing cancer in individuals with pathogenic BRCA1 or BRCA2 variants remains relatively unknown. We conducted the largest genome-wide analysis of CNVs in 15,342 BRCA1 and 10,740 BRCA2 pathogenic variant carriers. We used these results to prioritise a candidate breast cancer risk-modifier gene for laboratory analysis and biological validation. Notably, the HR for deletions in BRCA1 suggested an elevated breast cancer risk estimate (hazard ratio (HR) = 1.21), 95% confidence interval (95% CI = 1.09–1.35) compared with non-CNV pathogenic variants. In contrast, deletions overlapping SULT1A1 suggested a decreased breast cancer risk (HR = 0.73, 95% CI 0.59-0.91) in BRCA1 pathogenic variant carriers. Functional analyses of SULT1A1 showed that reduced mRNA expression in pathogenic BRCA1 variant cells was associated with reduced cellular proliferation and reduced DNA damage after treatment with DNA damaging agents. These data provide evidence that deleterious variants in BRCA1 plus SULT1A1 deletions contribute to variable breast cancer risk in BRCA1 carriers.

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

BackgroundClinical 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.MethodsOverall, 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.ResultsFor 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).ConclusionsPRSs 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.

Unique ER PR expression pattern in breast cancers with CHEK2 mutation: a hormone receptor and HER2 analysis based on germline cancer predisposition genes

PurposeEstrogen-receptor (ER) and progesterone-receptor (PR) expression levels in breast cancer, which have been principally compared via binomial descriptors, can vary widely across tumors. We sought to characterize ER and PR expression levels using semi-quantitative analyses of receptor staining in germline pathogenic variant (PV) carriers of cancer predisposition genes.MethodsWe conducted a retrospective chart review of patients who underwent germline genetic testing for cancer predisposition genes at a tertiary cancer center genetics clinic. We performed comparisons of semi-quantitative ER and PR percentage staining levels across carriers and non-carriers of cancer predisposition genes.ResultsBreast cancers from BRCA1 PV carriers expressed significantly lower ER (15.2% vs 78.2%, p < 0.001) and lower PR (6.8% vs 41.1%, p < 0.001) staining compared to non-PV carriers. Similarly, breast cancers of BRCA2 (66.7% vs 78.2%, p = 0.005) and TP53 (50.6% vs 78.2%, p = 0.015) PV tumors also displayed moderate decreases in ER staining. Conversely, CHEK2 tumors displayed higher ER (93.1% vs 78.2%, p = 0.005) and PR (72% vs 48.8%, p = 0.001) staining when compared to non-PV carriers. We observed a wide range of dispersion across the ER and PR staining levels of the carriers and noncarriers. ER and PR ranges of dispersion of CHEK2 tumors were uniquely narrower than all other groups.ConclusionThe findings of our study suggest that precise expression levels of ER and PR in breast cancers can vary widely. These differences are further augmented when comparing expression staining across PV and non-PV carriers, suggesting potentially unique tumorigenesis and progression pathways influenced by germline cancer predisposition genes.

Polygenic risk modeling for prediction of epithelial ovarian cancer risk

Polygenic risk scores (PRS) for epithelial ovarian cancer (EOC) have the potential to improve risk stratification. Joint estimation of Single Nucleotide Polymorphism (SNP) effects in models could improve predictive performance over standard approaches of PRS construction. Here, we implemented computationally efficient, penalized, logistic regression models (lasso, elastic net, stepwise) to individual level genotype data and a Bayesian framework with continuous shrinkage, “select and shrink for summary statistics” (S4), to summary level data for epithelial non-mucinous ovarian cancer risk prediction. We developed the models in a dataset consisting of 23,564 non-mucinous EOC cases and 40,138 controls participating in the Ovarian Cancer Association Consortium (OCAC) and validated the best models in three populations of different ancestries: prospective data from 198,101 women of European ancestries; 7,669 women of East Asian ancestries; 1,072 women of African ancestries, and in 18,915 BRCA1 and 12,337 BRCA2 pathogenic variant carriers of European ancestries. In the external validation data, the model with the strongest association for non-mucinous EOC risk derived from the OCAC model development data was the S4 model (27,240 SNPs) with odds ratios (OR) of 1.38 (95% CI: 1.28–1.48, AUC: 0.588) per unit standard deviation, in women of European ancestries; 1.14 (95% CI: 1.08–1.19, AUC: 0.538) in women of East Asian ancestries; 1.38 (95% CI: 1.21–1.58, AUC: 0.593) in women of African ancestries; hazard ratios of 1.36 (95% CI: 1.29–1.43, AUC: 0.592) in BRCA1 pathogenic variant carriers and 1.49 (95% CI: 1.35–1.64, AUC: 0.624) in BRCA2 pathogenic variant carriers. Incorporation of the S4 PRS in risk prediction models for ovarian cancer may have clinical utility in ovarian cancer prevention programs.

Altered regulation of BRCA1 exon 11 splicing is associated with breast cancer risk in carriers of BRCA1 pathogenic variants.

Germline pathogenic variants in BRCA1 confer a high risk of developing breast and ovarian cancer. The BRCA1 exon 11 (formally exon 10) is one of the largest exons and codes for the nuclear localization signals of the corresponding gene product. This exon can be partially or entirely skipped during pre-mRNA splicing, leading to three major in-frame isoforms that are detectable in most cell types and tissue, and in normal and cancer settings. However, it is unclear whether the splicing imbalance of this exon is associated with cancer risk. Here we identify a common genetic variant in intron 10, rs5820483 (NC_000017.11:g.43095106_43095108dup), which is associated with exon 11 isoform expression and alternative splicing, and with the risk of breast cancer, but not ovarian cancer, in BRCA1 pathogenic variant carriers. The identification of this genetic effect was confirmed by analogous observations in mouse cells and tissue in which a loxP sequence was inserted in the syntenic intronic region. The prediction that the rs5820483 minor allele variant would create a binding site for the splicing silencer hnRNP A1 was confirmed by pull-down assays. Our data suggest that perturbation of BRCA1 exon 11 splicing modifies the breast cancer risk conferred by pathogenic variants of this gene.

BRCA Genetic Test and Risk-Reducing Salpingo-Oophorectomy for Hereditary Breast and Ovarian Cancer: State-of-the-Art.

Simple SummaryThe BRCA genetic test and HRD (homologous recombination deficiency) test are used as a companion diagnosis before starting PARP (poly ADP-ribose polymerase) inhibitor treatment. In clinical practice, gynecologists treating ovarian cancer are faced with decisions such as whether to recommend germline BRCA (gBRCA) test to all ovarian cancer patients and whether to do the gBRCA test first or HRD test first. Regarding the judgment result of the HRD test, the cutoff value differs depending on the clinical trial, and the prevalence of gBRCA pathogenic variant rate is different in each histological type and country. RRSO (risk reducing salpingo-oophorectomy) may have possibly reduced the risk of breast cancer for BRCA2 pathogenic variant carriers but not for BRCA1 carriers.In the field of gynecology, the approval of the PARP inhibitors (PARPi) has been changing the treatment of ovarian cancer patients. The BRCA genetic test and the HRD test are being used as a companion diagnosis before starting PARPi treatment. BRACAnalysis CDx® and Myriad myChoice® HRD test are widely used as a BRCA genetic test and HRD test, respectively. In addition, FoundationOne®CDx is sometimes used as a tumor BRCA test and HRD test. In clinical practice, gynecologists treating ovarian cancer are faced with making decisions such as whether to recommend the gBRCA test to all ovarian cancer patients, whether to perform the gBRCA test first or HRD test first, and so on. Regarding the judgment result of the HRD test, the cutoff value differs depending on the clinical trial, and the prevalence of gBRCA pathogenic variant rate is different in each histological type and country. A prospective cohort study showed that RRSO reduced all-cause mortality in both pre- and postmenopausal women; however, RRSO significantly reduced the risk of breast cancer for BRCA2 pathogenic variant carriers, but not for BRCA1 pathogenic variant carriers. Moreover, salpingectomy alone is said to not decrease the risk of developing ovarian or breast cancer, so further discussion is evidently required. We discuss the current situation and problems in doing BRCA genetic test and RRSO in this review article.

Breast cancer ER, PR, and HER2 expression variance by germline cancer predisposition genes.

10526 Background: The association between breast cancer characteristics and survival with estrogen receptor (ER) and progesterone receptor (PR) expression has been primarily studied via binomial categories, ER-positive and ER-negative. In order to better characterize germline genetic influences on these markers, we investigated their IHC expression semi-quantitatively in cancer predisposition germline pathogenic variant (PV) carriers of the following genes: BRCA1, BRCA2, PALB2, TP53, PTEN, CDH1, ATM, CHEK2, and Lynch syndrome genes. The HER2 expression was also analyzed. Methods: We conducted a retrospective chart review of patients with germline panel genetic testing for cancer predisposition genes at Moffitt Cancer Center’s GeneHome clinic. Inclusion criteria included 1) women ≥18 years old, 2) breast cancer diagnosis, 3) cancer predisposition germline panel genetic test results, 4) available ER and PR expression levels, and 5) available HER expression and/or amplification status. ER, PR, and HER2 status were compared between PV carriers and non-PV carriers via Mann-Whitney U at p&gt;0.05. Results: A total of 847 cases were reviewed for the study. Among 658 patients with a breast cancer diagnosis and complete ER PR data, 365 cases (55.5%) were non-PV carriers and 293 cases (44.5%) carried a PV in at least one of the genes listed above. Among 635 cases with available HER2 expression/amplification status, 355 (55.9%) cases were non-PV carriers and 288 (45.4%) cases were PV-carriers. When compared with non-PV carrier controls, BRCA1 PV carriers’ breast tumors had significantly lower ER and/or PR expression. Further, BRCA2 and TP53 PV tumors also displayed moderately lower ER expression. Contrarily, CHEK2 tumors displayed higher ER and PR expression compared to controls. Further, BRCA1 and BRCA2 PV carriers were more likely to have HER2- breast cancers. Conclusions: Differences in ER, PR, HER2 expression levels were observed in germline PV carrier breast cancers, signaling differential impacts by germline PVs on the tumor evolution process. It is likely that tumor differences in PV carriers influence responses to therapies, including hormone therapy, anti-HER2 therapy, and subsequent survival.[Table: see text]

Family planning in carriers of BRCA1 and BRCA2 pathogenic variants

BRCA1 and BRCA2 pathogenic variant carriers have a high lifetime risk of developing breast and ovarian malignancies. Given the risks and significant ramifications of undergoing risk-reducing surgeries, many pathogenic variant carriers unaffected by cancer (previvors) struggle with family planning and reproductive decision making. The objective of this study was to determine the attitudes and practices of BRCA1 and BRCA2 pathogenic variant carriers with respect to family planning decision making. A cross-sectional survey was conducted of BRCA1 and BRCA2 previvors at four Northeastern medical centers. The survey was administered electronically via email using REDCap. The survey included demographic information as well as questions about genetic testing, prophylactic surgeries, family planning, and partnering. Data were analyzed with Fisher's exact tests and t tests. The survey was completed by 139 of 422 BRCA1 and BRCA2 pathogenic variant carriers (response rate 33%). Thirteen were excluded from analysis due to self-reported cancer history. Of the remaining 126, 21 (16.7%) were male and 105 (83.3%) were female. Female participants <35years old at the time of genetic testing were significantly more likely than those 35 or greater to report feeling urgency to have a family after finding out about their BRCA1 and BRCA2 pathogenic variant (p<0.0001). Younger women also reported their genetic status had a stronger impact on their romantic relationships (p=0.029). Men were significantly more likely to report that they felt no urgency to have a family compared to women (p<0.0001). Our study reflects the complex decision making for previvors and the intricacies of family planning in this population. Providers can use this knowledge as a guide to counsel patients about reproductive options.

Association of Risk-Reducing Salpingo-Oophorectomy With Breast Cancer Risk in Women With BRCA1 and BRCA2 Pathogenic Variants

Women with pathogenic variants in BRCA1 and BRCA2 are at high risk of developing breast and ovarian cancers. They usually undergo intensive cancer surveillance and may also consider surgical interventions, such as risk-reducing mastectomy or risk-reducing salpingo-oophorectomy (RRSO). Risk-reducing salpingo-oophorectomy has been shown to reduce ovarian cancer risk, but its association with breast cancer risk is less clear. To assess the association of RRSO with the risk of breast cancer in women with BRCA1 and BRCA2 pathogenic variants. This case series included families enrolled in the Breast Cancer Family Registry between 1996 and 2000 that carried an inherited pathogenic variant in BRCA1 (498 families) or BRCA2 (378 families). A survival analysis approach was used that was designed specifically to assess the time-varying association of RRSO with breast cancer risk and accounting for other potential biases. Data were analyzed from August 2019 to November 2020. Risk-reducing salpingo-oophorectomy. In all analyses, the primary end point was the time to a first primary breast cancer. A total of 876 families were evaluated, including 498 with BRCA1 (2650 individuals; mean [SD] event age, 55.8 [19.1] years; 437 White probands [87.8%]) and 378 with BRCA2 (1925 individuals; mean [SD] event age, 57.0 [18.6] years; 299 White probands [79.1%]). Risk-reducing salpingo-oophorectomy was associated with a reduced risk of breast cancer for BRCA1 and BRCA2 pathogenic variant carriers within 5 years after surgery (hazard ratios [HRs], 0.28 [95% CI, 0.10-0.63] and 0.19 [95% CI, 0.06-0.71], respectively), whereas the corresponding HRs were weaker after 5 years postsurgery (HRs, 0.64 [95% CI, 0.38-0.97] and 0.99 [95% CI; 0.84-1.00], respectively). For BRCA1 and BRCA2 pathogenic variant carriers who underwent RRSO at age 40 years, the cause-specific cumulative risk of breast cancer was 49.7% (95% CI, 40.0-60.3) and 52.7% (95% CI, 47.9-58.7) by age 70 years, respectively, compared with 61.0% (95% CI, 56.7-66.0) and 54.0% (95% CI, 49.3-60.1), respectively, for women without RRSO. Although the primary indication for RRSO is the prevention of ovarian cancer, it is also critical to assess its association with breast cancer risk in order to guide clinical decision-making about RRSO use and timing. The results of this case series suggest a reduced risk of breast cancer associated with RRSO in the immediate 5 years after surgery in women carrying BRCA1 and BRCA2 pathogenic variants, and a longer-term association with cumulative breast cancer risk in women carrying BRCA1 pathogenic variants.

Specialist oncological surgery for removal of the ovaries and fallopian tubes in BRCA1 and BRCA2 pathogenic variant carriers may reduce primary peritoneal cancer risk to very low levels.

Risk‐reducing bilateral salpingo‐oophorectomy (RRBSO) is highly effective for the prevention of high‐grade serous ovarian cancer (HGSOC) in BRCA1/2 pathogenic variant carriers (PVCs), but does not completely eliminate future risk of primary peritoneal cancer (PPC). The requirement to completely remove fallopian tubes at RRBSO and carefully exclude occult cancer/serous tubal intraepithelial carcinoma (STIC) lesions may not have been appreciated historically. We calculated rates of HGSOC and PPC in confirmed BRCA1/2 PVCs registered on the regional database in those who did (cases) and did not (controls) undergo RRBSO after genetic testing. Expected annual rates of ovarian/peritoneal cancer were 1% for BRCA1 ≥ 35 years and 0.5% for BRCA2 ≥ 45 years. Follow‐up before 35/45 years was “risk free” and lead time excluded RRBSO <35 years and <45 years for BRCA1 and BRCA2, respectively. Women were followed from personal mutation report (controls) or RRBSO (cases) to death, ovarian/peritoneal cancer or last follow‐up, whichever was sooner. In total, 891 cases (BRCA1 = 468, BRCA2 = 423) and 1302 controls had follow‐up ≥35 years (BRCA1 = 736) and ≥45 years (BRCA2 = 566), respectively, over a total of 7261.1 risk eligible years (mean = 8.15 years). Twenty‐one occult ovarian cancers were found at RRBSO (2.4%), 16 at stage 1. Post RRBSO, 56.97 ovarian/peritoneal cancers were expected but only 3 were observed (HR = 0.053; 95% CI = 0.013‐0.14), with combined Kaplan‐Meier analysis HR = 0.029 (95% CI = 0.009‐0.100, P < .001). Risk reduction was greater in specialist (HR = 0.03; 95% CI = 0.001‐0.13) compared to non‐specialist centres (HR = 0.11; 95% CI = 0.02‐0.37) (P = .07). In controls, 23.35 ovarian/peritoneal cancers were expected with 32 observed (HR = 1.37; 95% CI = 0.95‐1.91). RRBSO <35/<45 years reduces the risk of ovarian/peritoneal cancer by 95% in BRCA1/2 PVCs and may be greater in specialist centres.

An in-depth exploration of the post-test informational needs of BRCA1 and BRCA2 pathogenic variant carriers in Asia

IntroductionIdentification of one’s status as a BRCA1/2 pathogenic variant carrier often marks the start of navigating challenging decisions related to cancer risk management and result disclosure. Carriers report unmet informational needs, but studies have yet to explore the specific aspects of and how best to fulfill these needs. This study aims to explore the informational needs of BRCA1/2 pathogenic variant carriers in Asia to inform for the design of educational materials to support risk management decision-making.MethodsSemi-structured in-depth interviews were conducted with two male and 22 female English-speaking BRCA1/2 pathogenic variant carriers, aged 29–66 years, identified through the Cancer Genetics Service at the National Cancer Centre Singapore. A grounded theory approach with thematic analysis was undertaken to extract dominant themes.ResultsFour themes were identified: (i) proactive online information seeking behaviors (ii) personalized informational needs; (iii) challenges in sharing the results; and (iv) lack of genetic awareness.DiscussionParticipants highlight challenges with sharing their result arising from significant post-result informational needs, which have manifested into proactive online information-seeking behaviors. They desire for an online source of information, where content is personalized, reliable and local. Participants foresee the potential of an online resource to raise genetic awareness. This suggests the use of a culturally tailored online-based genetics resource, to promote result disclosure, empower risk-management decisions and raise genetic literacy rates.

Genome-Wide Gene Expression Analyses of BRCA1- and BRCA2-Associated Breast and Ovarian Tumours.

Simple SummaryVariants in the breast cancer susceptibility genes BRCA1 and BRCA2 increase the risk of developing breast and ovarian cancers. Over the past two decades researchers have aimed to identify gene expression changes associated with high-risk BRCA1 and BRCA2 variants. In this review we explore the replicability of BRCA1- and BRCA2-associated gene expression profiles in diseased and normal tissue. We highlight the impact of experimental factors and study designs on the comparability and utility of gene expression profiles associated with high-risk BRCA1 and BRCA2 variants. Additionally, we emphasise the importance of controlling for confounding molecular features that may influence the design of study cohort groups.Germline pathogenic variants in BRCA1 and BRCA2 increase cumulative lifetime risk up to 75% for breast cancer and 76% for ovarian cancer. Genetic testing for BRCA1 and BRCA2 pathogenic variants has become an important part of clinical practice for cancer risk assessment and for reducing individual risk of developing cancer. Genetic testing can produce three outcomes: positive (a pathogenic variant), uninformative (no pathogenic variant) and uncertain significance (a variant of unknown clinical significance). More than one third of BRCA1 and BRCA2 variants identified have been classified as variants of uncertain significance, presenting a challenge for clinicians. To address this important clinical challenge, a number of studies have been undertaken to establish a gene expression phenotype for pathogenic BRCA1 and BRCA2 variant carriers in several diseased and normal tissues. However, the consistency of gene expression phenotypes described in studies has been poor. To determine if gene expression analysis has been a successful approach for variant classification, we describe the design and comparability of 23 published gene expression studies that have profiled cells from BRCA1 and BRCA2 pathogenic variant carriers. We show the impact of advancements in expression-based technologies, the importance of developing larger study cohorts and the necessity to better understand variables affecting gene expression profiles across different tissue types.

Incidence of contralateral and ipsilateral breast cancers and prognosis in BRCA1/2 pathogenic variant carriers based on the Japanese HBOC Consortium registration

This study aimed to clarify the breast cancer prognosis in Japanese patients with BRCA1/2 pathogenic variant. We analyzed 2235 women with breast cancer who underwent BRCA1/2 genetic testing between 1996 and 2018 using data from the Japanese hereditary breast and ovarian cancer syndrome registry. The cumulative risk for contralateral and ipsilateral breast cancers and time to death since the first breast cancer were stratified based on the BRCA1/2 variant status. The median follow-up was 3.0 years (0.1-34.1 years) after the first breast cancer. The annual average risks of contralateral breast cancer in BRCA1 and BRCA2 and non-BRCA1/2 pathogenic variant carriers were 4.0%, 2.9%, and 1.9%, respectively (P = 0.001). The annual average risks of ipsilateral breast cancer in the three groups were 2.7%, 1.4%, and 1.1%, respectively (P = 0.06). BRCA1 pathogenic variant carriers had significantly higher risks of contralateral (hazard ratio 1.91, P < 0.001) and ipsilateral (hazard ratio 2.00, P = 0.02) breast cancers than non-BRCA1/2 pathogenic variant carriers. The time to death by the BRCA1/2 variant status was not significantly difference (P = 0.28). The prognosis of breast cancer patients who received standard treatment was comparable regardless of the BRCA1/2 variant status.