Follow-up of carriers of BRCA1 and BRCA2 variants of unknown significance: variant reclassification and surgical decisions

The Development and Evaluation of Novel Patient Educational Material for a Variant of Uncertain Significance (VUS) Result in Hereditary Cancer Genes

A Variant of Uncertain Significance (VUS) is a difference in the DNA sequence with uncertain consequences for gene function. A VUS in a hereditary cancer gene should not change medical care, yet some patients undergo medical procedures based on their VUS result, highlighting the unmet educational needs among patients and healthcare providers. To address this need, we developed, evaluated, and refined novel educational materials to explain that while VUS results do not change medical care, it remains important to share any personal or family history of cancer with family members given that their personal and family medical history can guide their cancer risk management. We began by reviewing the prior literature and transcripts from interviews with six individuals with a VUS result to identify content and design considerations to incorporate into educational materials. We then gathered feedback to improve materials via a focus group of multidisciplinary experts and multiple rounds of semi-structured interviews with individuals with a VUS result. Themes for how to improve content, visuals, and usefulness were used to refine the materials. In the final round of interviews with an additional 10 individuals with a VUS result, materials were described as relatable, useful, factual, and easy to navigate, and also increased their understanding of cancer gene VUS results.

Clinical implications of VUS reclassification in a single-centre series from application of ACMG/AMP classification rules specified for BRCA1/2

BACKGROUND

BRCA1/2 testing is crucial to guide clinical decisions in patients with hereditary breast/ovarian cancer, but detection of variants of uncertain significance (VUSs) prevents proper management of carriers. The ENIGMA (Evidence-based Network for the Interpretation of Germline Mutant Alleles) BRCA1/2 Variant Curation Expert Panel (VCEP) has recently developed BRCA1/2 variant classification guidelines consistent with ClinGen processes, specified against the ACMG/AMP (American College of Medical Genetics and Genomics/Association for Molecular-Pathology) classification framework.

METHODS

The ClinGen-approved BRCA1/2-specified ACMG/AMP classification guidelines were applied to BRCA1/2 VUSs identified from 2011 to 2022 in a series of patients, retrieving information from the VCEP documentation, public databases, literature and ENIGMA unpublished data. Then, we critically re-evaluated carrier families based on new results and checked consistency of updated classification with main sources for clinical interpretation of BRCA1/2 variants.

RESULTS

Among 166 VUSs detected in 231 index cases, 135 (81.3%) found in 197 index cases were classified by applying BRCA1/2-specified ACMG/AMP criteria: 128 (94.8%) as Benign/Likely Benign and 7 (5.2%) as Pathogenic/Likely Pathogenic. The average time from the first report as 'VUS' to classification using this approach was 49.4 months. Considering that 15 of these variants found in 64 families had already been internally reclassified prior to this work, this study provided 121 new reclassifications among the 151 (80.1%) remaining VUSs, relevant to 133/167 (79.6%) families.

CONCLUSIONS

These results demonstrated the effectiveness of new BRCA1/2 ACMG/AMP classification guidelines for VUS classification within a clinical cohort, and their important clinical impact. Furthermore, they suggested a cadence of no more than 3 years for regular review of VUSs, which however requires time, expertise and resources.

Variant reclassification and clinical implications

Genomic technologies have transformed clinical genetic testing, underlining the importance of accurate molecular genetic diagnoses. Variant classification, ranging from benign to pathogenic, is fundamental to these tests. However, variant reclassification, the process of reassigning the pathogenicity of variants over time, poses challenges to diagnostic legitimacy. This review explores the medical and scientific literature available on variant reclassification, focusing on its clinical implications.Variant reclassification is driven by accruing evidence from diverse sources, leading to variant reclassification frequency ranging from 3.6% to 58.8%. Recent studies have shown that significant changes can occur when reviewing variant classifications within 1 year after initial classification, illustrating the importance of early, accurate variant assignation for clinical care.Variants of uncertain significance (VUS) are particularly problematic. They lack clear categorisation but have influenced patient treatment despite recommendations against it. Addressing VUS reclassification is essential to enhance the credibility of genetic testing and the clinical impact. Factors affecting reclassification include standardised guidelines, clinical phenotype-genotype correlations through deep phenotyping and ancestry studies, large-scale databases and bioinformatics tools. As genomic databases grow and knowledge advances, reclassification rates are expected to change, reducing discordance in future classifications.Variant reclassification affects patient diagnosis, precision therapy and family screening. The exact patient impact is yet unknown. Understanding influencing factors and adopting standardised guidelines are vital for precise molecular genetic diagnoses, ensuring optimal patient care and minimising clinical risk.

PhenoScore quantifies phenotypic variation for rare genetic diseases by combining facial analysis with other clinical features using a machine-learning framework

Several molecular and phenotypic algorithms exist that establish genotype-phenotype correlations, including facial recognition tools. However, no unified framework that investigates both facial data and other phenotypic data directly from individuals exists. We developed PhenoScore: an open-source, artificial intelligence-based phenomics framework, combining facial recognition technology with Human Phenotype Ontology data analysis to quantify phenotypic similarity. Here we show PhenoScore's ability to recognize distinct phenotypic entities by establishing recognizable phenotypes for 37 of 40 investigated syndromes against clinical features observed in individuals with other neurodevelopmental disorders and show it is an improvement on existing approaches. PhenoScore provides predictions for individuals with variants of unknown significance and enables sophisticated genotype-phenotype studies by testing hypotheses on possible phenotypic (sub)groups. PhenoScore confirmed previously known phenotypic subgroups caused by variants in the same gene for SATB1, SETBP1 and DEAF1 and provides objective clinical evidence for two distinct ADNP-related phenotypes, already established functionally.

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

BACKGROUND

The 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.

METHODS

Data 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).

RESULTS

No 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.

CONCLUSIONS

We 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.

Practical considerations for reinterpretation of individual genetic variants

With the growing use of genetic testing in medicine, the question of when genetic findings should be reinterpreted in light of new data has become inescapable. The generation of population and disease-specific data, development of computational tools, and new understandings of the relationship of specific genes to disorders can all trigger changes in variant classification that may have important implications for patients and the clinicians caring for them. This is a particular concern for patients from groups underrepresented in current reference datasets, since they have higher rates of uncertain findings. Here we identify the challenges to implementing a systematic approach to variant reinterpretation and propose solutions. In particular, we address (a) the infrastructure needed to support implementation of systematic variant reinterpretation, (b) the issues around obtaining consent from patients for reinterpretation, (c) the process for triggering reinterpretation, (d) pathways for the flow of reinterpreted data, (e) considerations for how to cover the costs of reinterpretation, and (f) practical issues related to implementation of processes and policies that address these issues, including the importance of a fixed duration during which there is an expectation that variants will be reinterpreted.

Challenges in periodic revision of genetic testing results: Comparison of the main classification guidelines and report of a retrospective analysis involving BRCA1/BRCA2 variants of uncertain significance

In the context of cancer predisposition syndromes, it is widely known that the correct interpretation of germline variants identified in multigene panel testing is essential for adequate genetic counseling and clinical decision making, in which variants of uncertain significance (VUS) are not considered actionable findings. Thus, their periodic re-evaluation using appropriate guidelines is notably important. In the present study, we compared the performance of the main variant classification guidelines (ACMG, Sherloc and ENIGMA) in variant reassessment, using as input a BRCA1/2 VUS case series (retrospective analysis) from Brazil, an ethnically diverse and admixed country with substantial challenges in VUS reclassification. As main findings, two of the 15 VUS analyzed were reclassified as likely pathogenic by the 3 guidelines, BRCA1 c.4987-3C > G (rs397509213) and BRCA2 c.7868A > G (rs80359012). Moreover, challenges in variant classification and reassessment are described and additional in silico data about structural impact of the variant BRCA2 c.7868A > G are provided. We hypothesize that the establishment of a framework to reassess VUS could improve this process in health centers that have not yet implemented this practice. Results of this study underscore that periodic monitoring of the functional, clinical, and bioinformatics data of a VUS by a multidisciplinary team are of utmost importance in clinical practice. When there is a specific guideline for a given gene, such as ENIGMA for BRCA1/2, it should be considered the first option for variant assessment. Finally, recruitment of VUS carriers and their relatives to participate in variant segregation studies and publication of VUS reclassification results in the international scientific literature should be encouraged.

DeMAG predicts the effects of variants in clinically actionable genes by integrating structural and evolutionary epistatic features

Despite the increasing use of genomic sequencing in clinical practice, the interpretation of rare genetic variants remains challenging even in well-studied disease genes, resulting in many patients with Variants of Uncertain Significance (VUSs). Computational Variant Effect Predictors (VEPs) provide valuable evidence in variant assessment, but they are prone to misclassifying benign variants, contributing to false positives. Here, we develop Deciphering Mutations in Actionable Genes (DeMAG), a supervised classifier for missense variants trained using extensive diagnostic data available in 59 actionable disease genes (American College of Medical Genetics and Genomics Secondary Findings v2.0, ACMG SF v2.0). DeMAG improves performance over existing VEPs by reaching balanced specificity (82%) and sensitivity (94%) on clinical data, and includes a novel epistatic feature, the 'partners score', which leverages evolutionary and structural partnerships of residues. The 'partners score' provides a general framework for modeling epistatic interactions, integrating both clinical and functional information. We provide our tool and predictions for all missense variants in 316 clinically actionable disease genes (demag.org) to facilitate the interpretation of variants and improve clinical decision-making.

Model performance and interpretability of semi-supervised generative adversarial networks to predict oncogenic variants with unlabeled data

BACKGROUND

It remains an important challenge to predict the functional consequences or clinical impacts of genetic variants in human diseases, such as cancer. An increasing number of genetic variants in cancer have been discovered and documented in public databases such as COSMIC, but the vast majority of them have no functional or clinical annotations. Some databases, such as CiVIC are available with manual annotation of functional mutations, but the size of the database is small due to the use of human annotation. Since the unlabeled data (millions of variants) typically outnumber labeled data (thousands of variants), computational tools that take advantage of unlabeled data may improve prediction accuracy.

RESULT

To leverage unlabeled data to predict functional importance of genetic variants, we introduced a method using semi-supervised generative adversarial networks (SGAN), incorporating features from both labeled and unlabeled data. Our SGAN model incorporated features from clinical guidelines and predictive scores from other computational tools. We also performed comparative analysis to study factors that influence prediction accuracy, such as using different algorithms, types of features, and training sample size, to provide more insights into variant prioritization. We found that SGAN can achieve competitive performances with small labeled training samples by incorporating unlabeled samples, which is a unique advantage compared to traditional machine learning methods. We also found that manually curated samples can achieve a more stable predictive performance than publicly available datasets.

CONCLUSIONS

By incorporating much larger samples of unlabeled data, the SGAN method can improve the ability to detect novel oncogenic variants, compared to other machine-learning algorithms that use only labeled datasets. SGAN can be potentially used to predict the pathogenicity of more complex variants such as structural variants or non-coding variants, with the availability of more training samples and informative features.

Survival outcomes in patients with BRCA mutated, variant of unknown significance, and wild type ovarian cancer treated with PARP inhibitors

OBJECTIVE

Correlation between BRCA1/2 (BRCA) pathogenic variants and the response to poly (ADP-ribose) polymerase inhibitors (PARPi) has been recognized in patients with ovarian cancer. Moreover, data on the clinical implications of variants of unknown significance are lacking. The aim of this study was to evaluate differences in survival outcomes in patients with BRCA variants of unknown significance, mutated, and wild type relapsed ovarian cancer treated with PARPi.

METHODS

Patients with ovarian cancer whose somatic BRCA testing was available and who were receiving PARPi as maintenance treatment at the first recurrence between January 2014 and January 2021 were included in the present study and analyzed. Patients were divided into three groups according to BRCA mutational status (variant of unknown significance, mutated, and wild type). Progression-free survival was assessed in each study group.

RESULTS

Of 67 patients identified, 20 (29.9%), 24 (35.8%), and 23 (34.3%) had BRCA variant of unknown significance, mutated, and wild type, respectively. Patients received PARPi as maintenance treatment at the time of the first relapse after a complete response or partial response to platinum-based chemotherapy without differences in the previous platinum-free interval among the analyzed groups. The median progression-free survival of patients with BRCA mutation was significantly longer than for those with BRCA wild type or variant of unknown significance (not reached vs 4 months vs 7 months, respectively; p<0.001). Additionally, no significant difference was found between patients with BRCA wild type and BRCA variant of unknown significance (p=0.50).

CONCLUSION

Our study suggests that carriers of BRCA variant of unknown significance have survival outcomes comparable to patients with BRCA wild type and shorter progression-free survival than women harboring BRCA pathogenic variants.

Clinical and laboratory genetic counselor attitudes on the reporting of variants of uncertain significance for multigene cancer panels

Research suggests variants of uncertain significance (VUSs) present a variety of challenges for genetic counselors (GCs), nongenetics clinicians, and patients. Multigene cancer panels reveal more VUSs than single gene testing as a result of the increase in the number of genes being tested. This study surveyed 87 clinical cancer GCs involved with direct patient care and 19 laboratory GCs who provide guidance to clinicians regarding genetic test results about their attitudes on various options for the reporting of VUSs by laboratories for broad multigene cancer panels. Independent samples t-tests were utilized to compare the two groups. Based on a six-point Likert-type scale (1 = Strongly Disagree to 6 = Strongly Agree), clinical cancer GCs (M = 5.4; SD = 0.8) and laboratory GCs (M = 5.2; SD = 0.9) agreed overall that VUSs should be reported (p = 0.44; Cohen's d = 0.21). When asked about specific reporting options, both clinical cancer GCs (M = 1.9; SD = 1.1) and laboratory GCs (M = 2.1; SD = 1.4) disagreed that VUSs should be reported only for genes related to the indication for testing (p = 0.50; Cohen's d = 0.17). Overall, most GCs felt clinicians should not choose whether VUSs should be reported on genetic test results, with clinical cancer GCs (M = 1.9; SD = 1.3) feeling more strongly against it than laboratory GCs (M = 3.1; SD = 1.4; p = 0.002; Cohen's d = 0.88). Generally, GCs were more in favor of VUSs not being reported for population-based screening, with laboratory GCs (M = 4.7; SD = 0.8) agreeing more with that practice than clinical cancer GCs (M = 3.7; SD = 1.4; p = 0.001; Cohen's d = 0.80). Both clinical cancer GCs (M = 4.1; SD = 1.2) and laboratory GCs (M = 3.9; SD = 1.2) agreed additional guidelines on how to approach VUSs in clinical practice should be developed (p = 0.54; Cohen's d = 0.17). While most GCs supported the reporting of VUSs overall, our analyses suggest clinical cancer and laboratory GCs may have different attitudes toward specific VUS-related reporting options. Further research is needed to elucidate GC preferences to help inform best practices for the reporting of VUSs. The development of additional standardized guidelines on how to approach VUSs would further support clinical practice.

Occurrence of variants of unknown clinical significance in genetic testing for hereditary breast and ovarian cancer syndrome and Lynch syndrome: a literature review and analytical observational retrospective cohort study

BACKGROUND AND PURPOSE

Over the last decade, the implementation of multigene panels for hereditary tumor syndrome has increased at our institution (Inselspital, University Hospital Berne, Switzerland). The aim of this study was to determine the prevalence of variants of unknown significance (VUS) in patients with suspected Lynch syndrome and suspected hereditary breast and ovarian cancer syndrome, the latter in connection with the trend toward ordering larger gene panels.

RESULTS

Retrospectively collected data from 1057 patients at our institution showed at least one VUS in 126 different cases (11.9%). In patients undergoing genetic testing for BRCA1/2, the prevalence of VUS was 6%. When < 10 additional genes were tested in addition to BRCA1/2, the prevalence increased to 13.8%, and 31.8% for > 10 additional genes, respectively. The gene most frequently affected with a VUS was ATM. 6% of our patients who were tested for Lynch syndrome had a VUS result in either MLH1, MSH2 or MSH6.

CONCLUSIONS

Our data demonstrate that panel testing statistically significantly increases VUS rates due to variants in non-BRCA genes. Good genetic counseling before and after obtaining results is therefore particularly important when conducting multigene panels to minimize patient uncertainty due to VUS results.

Joint estimation and imputation of variant functional effects using high throughput assay data

Deep mutational scanning assays enable the functional assessment of variants in high throughput. Phenotypic measurements from these assays are broadly concordant with clinical outcomes but are prone to noise at the individual variant level. We develop a framework to exploit related measurements within and across experimental assays to jointly estimate variant impact. Drawing from a large corpus of deep mutational scanning data, we collectively estimate the mean functional effect per AA residue position within each gene, normalize observed functional effects by substitution type, and make estimates for individual allelic variants with a pipeline called FUSE (Functional Substitution Estimation). FUSE improves the correlation of functional screening datasets covering the same variants, better separates estimated functional impacts for known pathogenic and benign variants (ClinVar BRCA1, p=2.24×10-51), and increases the number of variants for which predictions can be made (2,741 to 10,347) by inferring additional variant effects for substitutions not experimentally screened. For UK Biobank patients who carry a rare variant in TP53, FUSE significantly improves the separation of patients who develop cancer syndromes from those without cancer (p=1.77×10-6). These approaches promise to improve estimates of variant impact and broaden the utility of screening data generated from functional assays.

Screening Programs for Breast Cancer: Toward Individualized, Risk-Adapted Strategies of Early Detection

Early detection of breast cancer (BC) comprises two approaches: screening of asymptomatic women in a specified target population at risk (usually a target age range for women at average risk), and early diagnosis for women with BC signs and symptoms. Screening for BC is a key health intervention for early detection. While population-based screening programs have been implemented for age-selected women, the pivotal clinical trials have not addressed the global utility nor the improvement of screening performance by utilizing more refined parameters for patient eligibility, such as individualized risk stratification. In addition, with the exception of the subset of women known to carry germline pathogenetic mutations in (high- or moderately-penetrant) cancer predisposition genes, such as BRCA1 and BRCA2, there has been less success in outreach and service provision for the unaffected relatives of women found to carry a high-risk mutation (i.e., "cascade testing") as it is in these individuals for whom such actionable information can result in cancers (and/or cancer deaths) being averted. Moreover, even in the absence of clinical cancer genetics services, as is the case for the immediate and at least near-term in most countries globally, the capacity to stratify the risk of an individual to develop BC has existed for many years, is available for free online at various sites/platforms, and is increasingly being validated for non-Caucasian populations. Ultimately, a precision approach to BC screening is largely missing. In the present chapter, we aim to address the concept of risk-adapted screening of BC, in multiple facets, and understand if there is a value in the implementation of adapted screening strategies in selected women, outside the established screening prescriptions, in the terms of age-range, screening modality and schedules of imaging.

Comprehensive clinical characterization of patients with BRCA1: c.5017_5019del germline variant

Purpose

We provide evidence for the reclassification of the BRCA1:c.5017_5019del variant by presenting the clinicopathological characteristics, clinical outcomes, and family history of breast or ovarian cancer in 17 patients with this variant.

Methods

This study included breast or ovarian cancer patients tested for BRCA1/2 genes between January 2008 and June 2020 at 10 medical centers in Korea. We retrospectively reviewed 17 probands from 15 families who had the BRCA1:c.5017_5019del variant according to the electronic medical records.

Results

We present 10 breast cancer patients and 7 ovarian cancer patients from 15 families identified as having BRCA1:c.5017_5019del and a total of 19 cases of breast cancer and 14 cases of ovarian cancer in these families. The ratio of breast-to-ovarian cancer was 1.3:1. Breast cancer patients with this variant showed a rich family history of breast or ovarian cancer, 8 patients (80.0%). The mean age at diagnosis was 45.4 years and 6 patients (60.0%) were categorized into hormone-receptor-negative breast cancer. Also, the ovarian cancer patients with this variant showed strong family histories of breast and/or ovarian cancer in 4 patients (57.1%).

Conclusion

We presented clinical evidence for the reclassification of BRCA1:c.5017_5019del as a likely pathogenic variant (LPV). Reclassification as LPV could result in the prophylactic treatment and medical surveillance of probands, family testing recommendations, and appropriate genetic counseling of their families.

The Challenge of Genetic Variants of Uncertain Clinical Significance : A Narrative Review

Genomic tests expand diagnostic and screening opportunities but also identify genetic variants of uncertain clinical significance (VUSs). Only a minority of VUSs are likely to prove pathogenic when later reassessed, but resolution of the uncertainty is rarely timely. That uncertainty adds complexity to clinical decision making and can result in harms and costs to patients and the health care system, including the time-consuming analysis required to interpret a VUS and the potential for unnecessary treatment and adverse psychological effects. Current efforts to improve variant interpretation will help reduce the scope of the problem, but the high prevalence of rare and novel variants in the human genome points to VUSs as an ongoing challenge. Additional strategies can help mitigate the potential harms of VUSs, including testing protocols that limit identification or reporting of VUSs, subclassification of VUSs according to the likelihood of pathogenicity, routine family-based evaluation of variants, and enhanced counseling efforts. All involve tradeoffs, and the appropriate balance of measures is likely to vary for different test uses and clinical settings. Cross-specialty deliberation and public input could contribute to systematic and broadly supported policies for managing VUSs.

Re-analysis of genomic data: An overview of the mechanisms and complexities of clinical adoption

Re-analyzing genomic information from a patient suspected of having an underlying genetic condition can improve the diagnostic yield of sequencing tests, potentially providing significant benefits to the patient and to the health care system. Although a significant number of studies have shown the clinical potential of re-analysis, less work has been performed to characterize the mechanisms responsible for driving the increases in diagnostic yield. Complexities surrounding re-analysis have also emerged. The terminology itself represents a challenge because "re-analysis" can refer to a range of different concepts. Other challenges include the increased workload that re-analysis demands of curators, adequate reimbursement pathways for clinical and diagnostic services, and the development of systems to handle large volumes of data. Re-analysis also raises ethical implications for patients and families, most notably when re-classification of a variant alters diagnosis, treatment, and prognosis. This review highlights the possibilities and complexities associated with the re-analysis of existing clinical genomic data. We propose a terminology that builds on the foundation presented in a recent statement from the American College of Medical Genetics and Genomics and describes each re-analysis process. We identify mechanisms for increasing diagnostic yield and provide perspectives on the range of challenges that must be addressed by health care systems and individual patients.

Impact of Variant Reclassification in Cancer Predisposition Genes on Clinical Care

PURPOSE

Genetic testing has clinical utility in the management of patients with hereditary cancer syndromes. However, the increased likelihood of encountering a variant of uncertain significance in individuals of non-European descent such as Asians may be challenging to both clinicians and patients. This study aims to evaluate the impact of variant reclassification in an Asian country with variants of uncertain significance reported in cancer predisposition genes.

METHODS

A retrospective analysis of patients seen at the Cancer Genetics Service at the National Cancer Centre Singapore between February 2014 and March 2020 was conducted. The frequency, direction, and time to variant reclassification were evaluated by comparing the reclassified report against the original report.

RESULTS

A total of 1,412 variants of uncertain significance were reported in 49.9% (845 of 1,695) of patients. Over 6 years, 6.7% (94 of 1,412) of variants were reclassified. Most variants of uncertain significance (94.1%, 80 of 85) were downgraded to benign or likely benign variant, with a smaller proportion of variants of uncertain significance (5.9%, 5 of 85) upgraded to pathogenic or likely pathogenic variant. Actionable variants of uncertain significance upgrades and pathogenic or likely pathogenic variant downgrades, which resulted in management changes, happened in 31.0% (39 of 126) of patients. The median and mean time taken for reclassification were 1 and 1.62 year(s), respectively.

CONCLUSION

We propose a clinical guideline to standardize management of patients reported to have variants of uncertain significance. Management should be based on the patient's personal history, family history, and variant interpretation. For clinically relevant or suspicious variants of uncertain significance, follow-up is recommended every 2 years, as actionable reclassifications may happen during this period.

BRCA1 Norway: comparison of classification for BRCA1 germline variants detected in families with suspected hereditary breast and ovarian cancer between different laboratories

Pathogenic germline variants in Breast cancer susceptibility gene 1 (BRCA1) predispose carriers to hereditary breast and ovarian cancer (HBOC). Through genetic testing of patients with suspected HBOC an increasing number of novel BRCA1 variants are discovered. This creates a growing need to determine the clinical significance of these variants through correct classification (class 1-5) according to established guidelines. Here we present a joint collection of all BRCA1 variants of class 2-5 detected in the four diagnostic genetic laboratories in Norway. The overall objective of the study was to generate an overview of all BRCA1 variants in Norway and unveil potential discrepancies in variant interpretation between the hospitals, serving as a quality control at the national level. For a subset of variants, we also assessed the change in classification over a ten-year period with increasing information available. In total, 463 unique BRCA1 variants were detected. Of the 126 variants found in more than one hospital, 70% were interpreted identically, while 30% were not. The differences in interpretation were mainly by one class (class 2/3 or 4/5), except for one larger discrepancy (class 3/5) which could affect the clinical management of patients. After a series of digital meetings between the participating laboratories to disclose the cause of disagreement for all conflicting variants, the discrepancy rate was reduced to 10%. This illustrates that variant interpretation needs to be updated regularly, and that data sharing and improved national inter-laboratory collaboration greatly improves the variant classification and hence increases the accuracy of cancer risk assessment.

Quantification of Discordant Variant Interpretations in a Large Family-Based Study of Li-Fraumeni Syndrome

PURPOSE

The use of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology guidelines has improved germline variant classification concordance, but discrepancies persist, sometimes directly affecting medical management. We evaluated variant discordance between and within families with germline TP53 variants in the National Cancer Institute's Li-Fraumeni syndrome longitudinal cohort study.

MATERIALS AND METHODS

Germline TP53 genetic testing results were obtained from 421 individuals in 140 families. A discordant test result was defined as a report of pathogenicity that differed between two clinical testing laboratories, between a testing laboratory and the ClinVar database, or between either the laboratory or ClinVar database and variant classification by internal study review.

RESULTS

There were 141 variants in 140 families (one family had two different TP53 variants). Fifty-four families had discordant interpretations (54 of 140, 39%). Sixteen families had discordant classifications leading to clinically important differences in medical management (16 of 140, 11%). Interfamilial discordance was observed between four families (two different variants). Intrafamilial discordance was observed within six families. One family experienced both intrafamilial and interfamilial discordance.

CONCLUSION

This large single-gene study found discordant germline TP53 variant interpretations in 39% of families studied; 11% had a variant with the potential to significantly affect medical management. This finding is especially concerning in patients with Li-Fraumeni syndrome because of their exceedingly high risks of multiple cancers and intensive cancer screening and risk-reducing recommendations. Centralized data sharing, gene-specific variant curation guidelines, and provider education for consistent variant interpretation are essential for optimal patient care.

Assessing the relationship between patient preferences for recontact after BRCA1 or BRCA2 genetic testing and their monitoring coping style in a Norwegian sample

Recontacting former patients regarding new genetic information is currently not standard care but might be implemented in the future. Little information is available on the implications of this practice from the point of view of former patients. The aim of this study was to investigate preferences for recontact when new genetic information becomes available among patients tested for BRCA pathogenic variants. We further wanted to investigate whether having a high or low information-seeking coping style (monitoring) impacts preferences. Preferences for recontact were assessed using a self-constructed questionnaire. The Threatening Medical Situations Inventory (TMSI) was used to measure monitoring coping style. The questionnaires were sent to 500 randomly selected patients who had previously been tested for BRCA pathogenic variants within the time frame 2001-2014 at one genetic clinic in Norway. We received 323 completed questionnaires. Most respondents wanted to be recontacted with advances in genetic medicine (81.1%) and to receive highly personalized updates. Genetic counselors/geneticists were believed to be most responsible for recontact. There was a significant relationship between being a high monitor and wanting recontact to learn about own cancer risk and receive ongoing support. Patients have a high interest in being recontacted. The findings indicated a tendency for high monitors to prefer more detailed and personalized information.

Amyotrophic Lateral Sclerosis Genetic Access Program: Paving the Way for Genetic Characterization of ALS in the Clinic

Objective

To report the frequency of amyotrophic lateral sclerosis (ALS) genetic variants in a nationwide cohort of clinic-based patients with ALS with a family history of ALS (fALS), dementia (dALS), or both ALS and dementia (fALS/dALS).

Methods

A multicenter, prospective cohort of 573 patients with fALS, dALS, or fALS/dALS, underwent genetic testing in the ALS Genetic Access Program (ALS GAP), a clinical program for clinics of the Northeast ALS Consortium. Patients with dALS underwent C9orf72 hexanucleotide repeat expansion (HRE) testing; those with fALS or fALS/dALS underwent C9orf72 HRE testing, followed by sequencing of SOD1, FUS, TARDBP, TBK1, and VCP.

Results

A pathogenic (P) or likely pathogenic (LP) variant was identified in 171/573 (30%) of program participants. About half of patients with fALS or fALS/dALS (138/301, 45.8%) had either a C9orf72 HRE or a P or LP variant identified in SOD1, FUS, TARDBP, TBK1, or VCP. The use of a targeted, 5-gene sequencing panel resulted in far fewer uncertain test outcomes in familial cases compared with larger panels used in other in clinic-based cohorts. Among dALS cases 11.8% (32/270) were found to have the C9orf72 HRE. Patients of non-Caucasian geoancestry were less likely to test positive for the C9orf72 HRE, but were more likely to test positive on panel testing, compared with those of Caucasian ancestry.

Conclusions

The ALS GAP program provided a genetic diagnosis to ∼1 in 3 participants and may serve as a model for clinical genetic testing in ALS.

Clinical management among individuals with variant of uncertain significance in hereditary cancer: A systematic review and meta-analysis

Improper medical use of variant of uncertain significance (VUS) remains a concern in hereditary cancer genetic testing. The goal of this study was to assess the association between pathogenic and likely pathogenic (P/LP), VUS, and benign and likely benign (B/LB) genetic test results and cancer-related surgical and screening management. Systematic searches of Medline, Embase, EBSCO CINAHL Plus, and PsycINFO were conducted from 1946 to August 26, 2020. Eligible studies included individuals with cancer genetic test result and surgical or screening management outcomes. We reviewed 885 abstracts and 22 studies that reported relevant surgical and screening outcomes were included. Meta-analysis revealed significantly higher surgical rates among individuals with P/LP than among those with VUS for therapeutic mastectomy with contralateral prophylactic mastectomy (OR = 7.35, 95% CI, 4.14-13.64), prophylactic mastectomy (OR = 3.05, 95% CI, 1.5-6.19), and oophorectomy (OR = 6.46, 95% CI, 3.64-11.44). There were no significant differences in therapeutic mastectomy, or breast conservation or lumpectomy rates between individuals with P/LP and VUS, or in any outcomes between patients with VUS and B/LB. Studies evaluating screening outcomes were limited, and results were conflicting. Comprehensive analysis do not indicate that a significant number of individuals with VUS results undergo inappropriate clinical management.

How patients deal with an ambiguous medical test: Decision-making after genetic testing

OBJECTIVE

We know little about how patients make decisions when they receive a variant of uncertain significance result (VUS) from genetic testing. The purpose of this study was to elucidate a model of patient-informed decision-making after receiving a VUS result.

METHODS

Using an adapted Mental Models Approach, we conducted semi-structured interviews with women who received a VUS result from genetic testing for hereditary breast cancer (N = 20) to explore factors they believed were relevant to their decision-making. Two coders used a coding scheme informed by experts in hereditary breast cancer to conduct analysis. Inter-coder reliability was α = .86.

RESULTS

Three overarching decision themes emerged from the interviews: managing ambiguity, medical risk management, and sharing results with others. While participants noted some difficulty understanding their result, genetic counselors' interpretations, psychosocial factors (e.g., risk perceptions), and competing extrinsic demands influenced their decisions.

CONCLUSION

Complex influences affect patient decision-making after a VUS result from genetic testing and may encourage health protective behavior.

PRACTICE IMPLICATIONS

Even patients who understand their test result could use support managing the ambiguity of their test result and sharing it with others.

Evaluation of literature searching tools for curation of mismatch repair gene variants in hereditary colon cancer

Pathogenic constitutional genomic variants in the mismatch repair (MMR) genes are the drivers of Lynch syndrome; optimal variant interpretation is required for the management of suspected and confirmed cases. The International Society for Hereditary Gastrointestinal Tumours (InSiGHT) provides expert classifications for MMR variants for the US National Human Genome Research Institute's (NHGRI) ClinGen initiative and interprets variants with discordant classifications and those of uncertain significance (VUSs). Given the onerous nature of extracting information related to variants, literature searching tools which harness artificial intelligence may aid in retrieving information to allow optimum variant classification. In this study, we described the nature of discordance in a sample of 80 variants from a list of variants requiring updating by InSiGHT for ClinGen by comparing their existing InSiGHT classifications with the various submissions for each variant on the US National Centre for Biotechnology Information's (NCBI) ClinVar database. To identify the potential value of a literature searching tool in extracting information related to classification, all variants were searched for using a traditional method (Google Scholar) and literature searching tool (Mastermind) independently. Descriptive statistics were used to compare: the number of articles before and after screening for relevance and the number of relevant articles unique to either method. Relevance was defined as containing the variant in question as well as data informing variant interpretation. A total of 916 articles were returned by both methods and Mastermind averaged four relevant articles per search compared to Google Scholar's three. Of relevant Mastermind articles, 193/308 (62.7%) were unique to it, compared to 87/202, (43.0%) for Google Scholar. For 24 variants, either or both methods found no information. All 6/80 (20%) variants with pathogenic or likely pathogenic InSiGHT classifications have newer VUS assertions on ClinVar. Our study demonstrated that for a sample of variants with varying discordant interpretations, Mastermind was able to return on average, a more relevant and unique literature search. Google Scholar was able to retrieve information that Mastermind did not, which supports a conclusion that Mastermind could play a complementary role in literature searching for classification. This work will aid InSiGHT in its role of classifying MMR variants.

Should All Individuals Be Screened for Genetic Predisposition to Cancer?

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Evaluation of Clinical Practices Related to Variants of Uncertain Significance Results in Inherited Cardiac Arrhythmia and Inherited Cardiomyopathy Genes

Background:

Increasing use of genetic tests have identified many variants of uncertain significance (VUS) in genes associated with inherited arrhythmias and cardiomyopathies. Evaluation of clinical practices, including medical management recommendations for VUS patients and their families, is important to prevent over- or under-treatment that may result in morbidity or mortality. The purpose of this study is to describe practices related to VUS results including information and medical management recommendations providers give patients and their families.

Methods:

An anonymous online survey was distributed to genetic counselors (GCs) and cardiologists who have seen at least one patient for inherited arrhythmias or cardiomyopathies. The survey explored providers’ confidence in counseling, explanation of VUSs, topics covered before and after genetic testing, and clinical recommendations using a hypothetical scenario maximizing uncertainty with an unclear clinical and molecular diagnosis. Descriptive statistics were calculated, and median confidence and likelihood of making various medical recommendations were compared across provider type.

Results:

Providers (N=102) who completed the survey included 29 cardiovascular GCs, 50 GCs from other specialties, and 23 cardiologists. GCs feel more confident than cardiologists counseling about VUS results ( P <0.001); while both cardiovascular GCs and cardiologists feel more confident than other GCs in providing input regarding medical management recommendations ( P =0.001 and P =0.01, respectively). Cardiologists were more likely than cardiac GCs to recommend clinical testing for family members even though testing in the scenario is expected to be uninformative.

Conclusions:

These findings illustrate how the expertise of different providers may impact decision processes, suggesting the need for interdisciplinary clinics to optimize care for challenging cases.

Whole genome sequencing for the investigation of canine mammary tumor inheritance - an initial assessment of high-risk breast cancer genes reveal BRCA2 and STK11 variants potentially associated with risk in purebred dogs

Background

Although, in general, cancer is considered a multifactorial disease, clustering of particular cancers in pedigrees suggests a genetic predisposition and could explain why some dog breeds appear to have an increased risk of certain cancers. To our knowledge, there have been no published reports of whole genome sequencing to investigate inherited canine mammary tumor (CMT) risk, and with little known about CMT genetic susceptibility, we carried out whole genome sequencing on 14 purebred dogs diagnosed with mammary tumors from four breed-specific pedigrees. Following sequencing, each dog’s data was processed through a bioinformatics pipeline. This initial report highlights variants in orthologs of human breast cancer susceptibility genes.

Results

The overall whole genome and exome coverage averages were 26.0X and 25.6X, respectively, with 96.1% of the genome and 96.7% of the exome covered at least 10X. Of the average 7.9 million variants per dog, initial analyses involved surveying variants in orthologs of human breast cancer susceptibility genes, BRCA1, BRCA2, CDH1, PTEN, STK11, and TP53, and identified 19 unique coding variants that were validated through PCR and Sanger sequencing. Statistical analyses identified variants in BRCA2 and STK11 that appear to be associated with CMT, and breed-specific analyses revealed the breeds at the highest risk. Several additional BRCA2 variants showed trends toward significance, but have conflicting interpretations of pathogenicity, and correspond to variants of unknown significance in humans, which require further investigation. Variants in other genes were noted but did not appear to be associated with disease.

Conclusions

Whole genome sequencing proves to be an effective method to elucidate risk of CMT. Risk variants in orthologs of human breast cancer susceptibility genes have been identified. Ultimately, these whole genome sequencing efforts have provided a plethora of data that can also be assessed for novel discovery and have the potential to lead to breakthroughs in canine and human research through comparative analyses.

Cascading After Peridiagnostic Cancer Genetic Testing: An Alternative to Population-Based Screening

PURPOSE

Despite advances in DNA sequencing technology and expanded medical guidelines, the vast majority of individuals carrying pathogenic variants of common cancer susceptibility genes have yet to be identified. An alternative to population-wide genetic screening of healthy individuals would exploit the trend for genetic testing at the time of cancer diagnosis to guide therapy and prevention, combined with augmented familial diffusion or "cascade" of genomic risk information.

METHODS

Using a multiple linear regression model, we derived the time interval to detect an estimated 3.9 million individuals in the United States with a pathogenic variant in 1 of 18 cancer susceptibility genes. We analyzed the impact of the proportion of incident patients sequenced, varying observed frequencies of pathogenic germline variants in patients with cancer, differential rates of diffusion of genetic information in families, and family size.

RESULTS

The time to detect inherited cancer predisposing variants in the population is affected by the extent of cascade to first-, second-, and third-degree relatives (FDR, SDR, TDR, respectively), family size, prevalence of mutations in patients with cancer, and the proportion of patients with cancer sequenced. In a representative scenario, assuming a 7% prevalence of pathogenic variants across cancer types, an average family size of 3 per generation, and 15% of incident patients with cancer in the United States undergoing germline testing, the time to detect all 3.9 million individuals with pathogenic variants in 18 cancer susceptibility genes would be 46.2, 22.3, 13.6, and 9.9 years if 10%, 25%, 50%, and 70%, respectively, of all FDR, SDR, and TDR were tested for familial mutations.

CONCLUSION

Peridiagnostic and cascade cancer genetic testing offers an alternative strategy to achieve population-wide identification of cancer susceptibility mutations.

Patient perspectives on variant reclassification after cancer susceptibility testing

BACKGROUND

Little is known about the impact of reclassification on patients' perception of medical uncertainty or trust in genetics-based clinical care.

METHODS

Semistructured telephone interviews were conducted with 20 patients who had received a reclassified genetic test result related to hereditary cancer. All participants had undergone genetic counseling and testing for cancer susceptibility at Vanderbilt-Ingram Cancer Center Hereditary Cancer Clinic within the last six years.

RESULTS

Most of the participants did not express distress related to the variant reclassification and only a minority expressed a decrease in trust in medical genetics. However, recall of the new interpretation was limited, even though all participants were recontacted by letter, phone, or clinic visit.

CONCLUSION

Reclassification of genetic tests is an important issue in modern healthcare because changes in interpretation have the potential to alter previously recommended management. Participants in this study did not express strong feelings of mistrust or doubt about their genetic evaluation. However, there was a low level of comprehension and information retention related to the updated report. Future research can build on this study to improve communication with patients about their reclassified results.

Is there a duty to reinterpret genetic data? The ethical dimensions

The evolving evidence base for the interpretation of variants identified in genetic and genomic testing has presented the genetics community with the challenge of variant reinterpretation. In particular, it is unclear whether an ethical duty of periodic reinterpretation should exist, who should bear that duty, and what its dimensions should be. Based on an analysis of the ethical arguments for and against a duty to reinterpret, we conclude that a duty should be recognized. Most importantly, by virtue of ordering and conducting tests likely to produce data on variants that cannot be definitively interpreted today, the health-care system incurs a duty to reinterpret when more reliable data become available. We identify four elements of the proposed ethical duty: data storage, initiation of reinterpretation, conduct of reinterpretation, and patient recontact, and we identify the parties best situated to implement each component. We also consider the reasonable extent and duration of a duty, and the role of the patient's consent in the process, although we acknowledge that some details regarding procedures and funding still need to be addressed. The likelihood of substantial patient benefit from a systematic approach to reinterpretation suggests the importance for the genetics community to reach consensus on this issue.

Diagnostic yield of a custom-designed multi-gene cancer panel in Irish patients with breast cancer

BACKGROUND

Breast cancer is genetically heterogeneous, and parellel multi-gene sequencing is the most cost- and time-efficient manner to investigate breast cancer predisposition. Numerous multi-gene panels (MGPs) are commercially available, but many include genes with weak/unproven associaton with breast cancer, or with predisposition to cancer of other types. This study investigates the utility of a custom-designed multi-gene panel in an Irish cohort with breast cancer.

METHODS

A custom panel comprising 83 genes offered by 19 clinical "breast cancer predisposition" MGPs was designed and applied to germline DNA from 91 patients with breast cancer and 77 unaffected ethnicially matched controls. Variants were identified and classified using a custom pipeline.

RESULTS

Nineteen loss-of-function (LOF) and 334 missense variants were identified. After removing common and/or benign variants, 15 LOF and 30 missense variants were analysed. Variants in known breast cancer susceptibility genes were identified, including in BRCA1 and ATM in cases, and in NF1 and CHEK2 in controls. Most variants identified were in genes associated with predisposition to cancers other than breast cancer (BRIP1, RAD50, MUTYH, and mismatch repair genes), or in genes with unknown or unproven association with cancer.

CONCLUSION

Using multi-gene panels enables rapid, cost-effective identification of individuals with high-risk cancer predisposition syndromes. However, this approach also leads to an increased amount of uncertain results. Clinical management of individuals with particular genetic variants in the absence of a matching phenotype/family history is challenging. Further population and functional evidence is required to fully elucidate the clinical relevance of variants in genes of uncertain significance.

Prostate cancer research: The next generation; report from the 2019 Coffey-Holden Prostate Cancer Academy Meeting

INTRODUCTION

The 2019 Coffey-Holden Prostate Cancer Academy (CHPCA) Meeting, "Prostate Cancer Research: The Next Generation," was held 20 to 23 June, 2019, in Los Angeles, California.

METHODS

The CHPCA Meeting is an annual conference held by the Prostate Cancer Foundation, that is uniquely structured to stimulate intense discussion surrounding topics most critical to accelerating prostate cancer research and the discovery of new life-extending treatments for patients. The 7th Annual CHPCA Meeting was attended by 86 investigators and concentrated on many of the most promising new treatment opportunities and next-generation research technologies.

RESULTS

The topics of focus at the meeting included: new treatment strategies and novel agents for targeted therapies and precision medicine, new treatment strategies that may synergize with checkpoint immunotherapy, next-generation technologies that visualize tumor microenvironment (TME) and molecular pathology in situ, multi-omics and tumor heterogeneity using single cells, 3D and TME models, and the role of extracellular vesicles in cancer and their potential as biomarkers.

DISCUSSION

This meeting report provides a comprehensive summary of the talks and discussions held at the 2019 CHPCA Meeting, for the purpose of globally disseminating this knowledge and ultimately accelerating new treatments and diagnostics for patients with prostate cancer.

Regarding the Yin and Yang of Precision Cancer- Screening and Treatment: Are We Creating a Neglected Majority?

In this commentary, we submit that the current emphasis of precision cancer screening and treatment (PCST) has been to provide and interpret the implications of "positive" screening results for those deemed to be at greatest risk for cancer or most likely to benefit from targeted treatments. This is an important, but proportionately small target group, regardless of the cancer context. Overlooked by this focus is the larger majority of those screened who receive "negative" results. We contend that for optimal dissemination of PCST, the complement of positive and negative results be viewed as an inseparable yin-yang duality with the needs of those who receive negative screening results viewed as important as those deemed to be at highest risk or derive targeted treatment benefit. We describe three areas where communication of negative PCST results warrant particular attention and research consideration: population-based family history screening, germline testing for hereditary cancer syndromes, and tumor testing for targeted cancer treatment decision-making. Without thoughtful consideration of the potential for negative results to have psychological and behavioral influences, there is a potential to create a "neglected majority". This majority may be inclined to misinterpret results, disseminate inaccurate information to family, dismiss the credibility of results, or become disillusioned with existing medical treatments.

Psychosocial problems in women attending French, German and Spanish genetics clinics before and after targeted or multigene testing results: an observational prospective study

OBJECTIVES AND SETTING

Advances in multigene panel testing for cancer susceptibility has increased the complexity of counselling, requiring particular attention to counselees' psychosocial needs. Changes in psychosocial problems before and after genetic testing were prospectively compared between genetic test results in women tested for breast or ovarian cancer genetic susceptibility in French, German and Spanish clinics.

PARTICIPANTS AND MEASURES

Among 752 counselees consecutively approached, 646 (86%) were assessed after the initial genetic consultation (T1), including 510 (68%) affected with breast cancer, of which 460 (61%) were assessed again after receiving the test result (T2), using questionnaires addressing genetic-specific psychosocial problems (Psychosocial Aspects of Hereditary Cancer (PAHC)-six scales). Sociodemographic and clinical data were also collected.

RESULTS

Seventy-nine (17.2%), 19 (4.1%), 259 (56.3%), 44 (9.6%) and 59 (12.8%) women received a BRCA1/2, another high/moderate-risk pathogenic variant (PV), negative uninformative, true negative (TN) or variant of uncertain significance result (VUS), respectively. On multiple regression analyses, compared with women receiving another result, those with a VUS decreased more in psychosocial problems related to hereditary predisposition (eg, coping with the test result) (ß=-0.11, p<0.05) and familial/social issues (eg, risk communication) (ß=-0.13, p<0.05), almost independently from their problems before testing. Women with a PV presented no change in hereditary predisposition problems and, so as women with a TN result, a non-significant increase in familial/social issues. Other PAHC scales (ie, emotions, familial cancer, personal cancer and children-related issues) were not affected by genetic testing.

CONCLUSIONS

In women tested for breast or ovarian cancer genetic risk in European genetics clinics, psychosocial problems were mostly unaffected by genetic testing. Apart from women receiving a VUS result, those with another test result presented unchanged needs in counselling in particular about hereditary predisposition and familial/social issues.

Perceptions of genetic variant reclassification in patients with inherited cardiac disease

Interpretation of sequence variants is an ongoing challenge and new approaches aim to increase stringency. The reclassification of variants has the potential to alter medical management and elicit psychosocial consequences for patients. The perspective of patients with an inherited cardiac disease and a clinically significant variant reclassification was explored through semi-structured phone interviews. Participants were recruited from two specialized multidisciplinary centers in Canada and Australia. Qualitative analysis was performed through a thematic analysis approach. Fifteen participants were interviewed, including 9 (60%) with an inherited cardiomyopathy and 6 (40%) with an inherited arrhythmia syndrome. Six (40%) patients had a classification upgrade, while 9 (60%) had a downgrade. Four major themes emerged: (1) reactions towards the reclassified variant; (2) impact on decision-making; (3) perception of the reclassification process; and (4) improvement of the reclassification process. Many patients adjusted to the reclassification, however some misunderstood the implications, impacting their responses and decision-making. In conclusion, careful discussion with patients about uncertainty and the potential for reclassification are crucial to ensure a deeper understanding of the outcome of genetic testing and impact on families.

The influence of BRCA variants of unknown significance on cancer risk management decision-making

OBJECTIVE

To compare gynecological cancer risk management between women with BRCA variants of unknown significance (VUS) to women with negative genetic testing.

METHODS

Ninety-nine patients whose BRCA genetic testing yielded VUS were matched with 99 control patients with definitive negative BRCA results at a single institution. Demographics and risk management decisions were obtained through chart review. Primary outcome was the rate of risk-reducing bilateral salpingo-oophorectomy (RRBSO). Chi square tests, t-tests, and logistic regression were performed, with significance of p<0.05.

RESULTS

VUS patients were more likely to be non-Caucasian (p=0.000) and of Ashkenazi-Jewish descent (p=0.000). There was no difference in gynecologic oncology referrals or recommendations to screen or undergo risk-reducing surgery for VUS vs. negative patients. Ultimately, 44 patients (22%) underwent RRBSO, with no significant difference in surgical rate based on the presence of VUS. Ashkenazi-Jewish descent was associated with a 4.5 times increased risk of RRBSO (OR=4.489; 95% CI=1.484-13.579) and family history of ovarian cancer was associated with a 2.6 times risk of RRBSO (OR=2.641; 95% CI=1.107-6.299).

CONCLUSION

In our institution, patients with VUS were surgically managed similarly to those with negative BRCA testing. The numbers of patients with VUS are likely to increase with the implementation of multi-gene panel testing. Our findings underscore the importance of genetic counseling and individualized screening and prevention strategies in the management of genetic testing results.

Insights into BRCA Cancer Predisposition from Integrated Germline and Somatic Analyses in 7632 Cancers

BACKGROUND

It is often assumed any cancer in a germline BRCA1 or BRCA2 (collectively termed BRCA) mutation carrier was caused by that mutation. It is also often assumed the occurrence of breast or ovarian cancer in an individual with a variant of uncertain significance (VUS) suggests the VUS is pathogenic. These assumptions have profound management implications for cancer patients and healthy individuals.

METHODS

We compared the frequency of BRCA mutations, allele loss, and Signature 3 in 7632 individuals with 28 cancers and 1000 population controls. Because only increased frequency was the focus of the study, all statistical tests were one-sided.

RESULTS

Individuals with breast or ovarian cancer had increased germline BRCA pathogenic mutation frequencies compared to controls (P = 1.0x10-10 and P = 1.4x10-34, respectively). There was no increase in other cancer types. Wild-type allele loss and Signature 3 were statistically significantly higher in breast and ovarian cancers with BRCA mutations compared with other cancers with BRCA mutations (P = 5.1x10-10 and P = 3.7x10-9) and cancers without BRCA mutations (P = 2.8x10-53 and P = 1.0x10-134). There was no difference between non-breast and non-ovarian cancers with BRCA mutations and cancers without BRCA mutations. Allele loss and Signature 3 were statistically significantly higher in breast and ovarian cancers in individuals with BRCA pathogenic mutations compared to those with VUS (P = 3.8x10-17 and P = 1.6x10-8) or benign variants (P = 1.2x10-28 and P = 2.2x10-10). There was no difference between individuals with BRCA VUS and those with benign variants.

CONCLUSIONS

These data show that non-breast and non-ovarian cancers in individuals with germline BRCA pathogenic mutations are often not causally related to the mutation and that BRCA VUS are highly unlikely to be pathogenic. These results should reduce inappropriate management of germline BRCA information.

Variant classification changes over time in BRCA1 and BRCA2

PURPOSE

To report BRCA1 and BRCA2 (BRCA1/2) variant reassessments and reclassifications between 2012 and 2017 at the Advanced Molecular Diagnostics Laboratory (AMDL) in Toronto, Canada, which provides BRCA1/2 testing for patients in Ontario, and to compare AMDL variant classifications with submissions in ClinVar.

METHODS

Variants were assessed using a standardized variant assessment tool based on the American College of Medical Genetics and Genomics/Association for Molecular Pathology's guidelines and tracked in an in-house database. Variants were shared through the Canadian Open Genetics Repository and submitted to ClinVar for comparison against other laboratories.

RESULTS

AMDL identified 1209 BRCA1/2 variants between 2012 and 2017. During this period, 32.9% (398/1209) of variants were reassessed and 12.4% (150/1209) were reclassified. The majority of reclassified variants were downgraded (112/150, 74.7%). Of the reclassified variants, 63.3% (95/150) were reclassified to benign, 20.7% (31/150) to likely benign, 10.0% (15/150) to variant of uncertain significance, 2.0% (3/150) to likely pathogenic, and 4.0% (6/150) to pathogenic. Discordant ClinVar submissions were found for 40.4% (488/1209) of variants.

CONCLUSION

BRCA1/2 variants may be reclassified over time. Reclassification presents ethical and practical challenges related to recontacting patients. Data sharing is essential to improve variant interpretation, to help patients receive appropriate care based on their genetic results.

The Responsibility to Recontact Research Participants after Reinterpretation of Genetic and Genomic Research Results

The evidence base supporting genetic and genomic sequence-variant interpretations is continuously evolving. An inherent consequence is that a variant's clinical significance might be reinterpreted over time as new evidence emerges regarding its pathogenicity or lack thereof. This raises ethical, legal, and financial issues as to whether there is a responsibility to recontact research participants to provide updates on reinterpretations of variants after the initial analysis. There has been discussion concerning the extent of this obligation in the context of both research and clinical care. Although clinical recommendations have begun to emerge, guidance is lacking on the responsibilities of researchers to inform participants of reinterpreted results. To respond, an American Society of Human Genetics (ASHG) workgroup developed this position statement, which was approved by the ASHG Board in November 2018. The workgroup included representatives from the National Society of Genetic Counselors, the Canadian College of Medical Genetics, and the Canadian Association of Genetic Counsellors. The final statement includes twelve position statements that were endorsed or supported by the following organizations: Genetic Alliance, European Society of Human Genetics, Canadian Association of Genetic Counsellors, American Association of Anthropological Genetics, Executive Committee of the American Association of Physical Anthropologists, Canadian College of Medical Genetics, Human Genetics Society of Australasia, and National Society of Genetic Counselors.

The transformation of medical genetics by clinical genomics: hubris meets humility

There is no question that the advent of massively parallel ("next-generation") DNA sequencing has thrust Medical Genetics and Molecular Diagnostics into a new era, availing practitioners and patients of a form of genetic testing unprecedented in its scope and comprehensiveness. It has produced impressive diagnostic yield, ended the "diagnostic odyssey" for many patients and families, expanded the known phenotypes of countless disorders, and led to almost weekly new disease gene discoveries. Nevertheless, it still fails to identify the molecular cause of many patients who clearly exhibit genetic/syndromic conditions, while at the same time unmasking other sequence changes of uncertain significance or unexpected consequences. With over six years' experience in the clinical application of NGS, this seems an opportune time to take stock and face up honestly to how much we still do not know about genome action and, indeed, the DNA molecule itself. This review and assessment examines a number of residual deficiencies and misconceptions in clinical genomics, while daring to predict its future incorporation of other "-omics" approaches and even quantum phenomena in our unending quest to understand the heredity of Homo sapiens.

Reinterpretation of BRCA1 and BRCA2 variants of uncertain significance in patients with hereditary breast/ovarian cancer using the ACMG/AMP 2015 guidelines

BACKGROUND

Although BRCA1 or BRCA2 (BRCA1/2) genetic testing plays an important role in determining treatment modalities in patients with hereditary breast and ovarian cancer, sequence variants with unknown clinical significance or variant of uncertain significance (VUS) have limited use in medical decision-making. With vast quantities of gene-related data being updated, the clinical significance of VUS may change over time. We reinterpreted the sequence variant previously reported as BRCA1/2 VUS results in patients with breast or ovarian cancer and assessed whether the clinical significance of VUS was changed.

METHODS

We retrospectively reviewed medical records of 423 breast or ovarian cancer patients who underwent BRCA1/2 genetic testing from 2010 to 2017. The VUSs in BRCA1/2 were reanalyzed using the 2015 American College of Medical Genetics and Genomics and the Association for Molecular Pathology standards and guidelines (ACMG/AMP 2015 guidelines) and the VUS was reclassified into five categories: "pathogenic", "likely pathogenic", "VUS", "likely benign", and "benign".

RESULTS

A total of 75 patients (48 sequence types of VUS) were identified as carrying either one or more VUS in BRCA1/2. Among the 75 patients, two patients (2.7%) were reclassified as "likely pathogenic", 30 patients (40.0%) were reclassified as either "benign" or "likely benign", and the remaining 43 patients (57.3%) were still classified as VUS category.

CONCLUSIONS

Since the clinical significance of VUS in BRCA1/2 may vary from time to time, reinterpretation of the VUS results could contribute to clinical decision-making.

A comparison of cosegregation analysis methods for the clinical setting

Quantitative cosegregation analysis can help evaluate the pathogenicity of genetic variants. However, genetics professionals without statistical training often use simple methods, reporting only qualitative findings. We evaluate the potential utility of quantitative cosegregation in the clinical setting by comparing three methods. One thousand pedigrees each were simulated for benign and pathogenic variants in BRCA1 and MLH1 using United States historical demographic data to produce pedigrees similar to those seen in the clinic. These pedigrees were analyzed using two robust methods, full likelihood Bayes factors (FLB) and cosegregation likelihood ratios (CSLR), and a simpler method, counting meioses. Both FLB and CSLR outperform counting meioses when dealing with pathogenic variants, though counting meioses is not far behind. For benign variants, FLB and CSLR greatly outperform as counting meioses is unable to generate evidence for benign variants. Comparing FLB and CSLR, we find that the two methods perform similarly, indicating that quantitative results from either of these methods could be combined in multifactorial calculations. Combining quantitative information will be important as isolated use of cosegregation in single families will yield classification for less than 1% of variants. To encourage wider use of robust cosegregation analysis, we present a website ( http://www.analyze.myvariant.org ) which implements the CSLR, FLB, and Counting Meioses methods for ATM, BRCA1, BRCA2, CHEK2, MEN1, MLH1, MSH2, MSH6, and PMS2. We also present an R package, CoSeg, which performs the CSLR analysis on any gene with user supplied parameters. Future variant classification guidelines should allow nuanced inclusion of cosegregation evidence against pathogenicity.

Patients' perspectives of variants of uncertain significance and strategies for uncertainty management

Variants of uncertain significance (VUS) are a well-recognized source of uncertainty in genomic medicine. Despite the existence of straightforward clinical management recommendations, patients report feeling anxiety, worry, and uncertainty in response to VUS. We report the first structured analysis of patient perspectives of VUS-related uncertainty in genome sequencing using Han's taxonomy of genomic uncertainty. We conducted in-depth semi-structured interviews with 11 patients to elicit their thoughts regarding implications of the result for themselves and their family members. Patients' primary concern with VUS-related uncertainty involved personal and practical issues as they directly inform health-care decisions. Patients demonstrated good understanding of the epistemic nature of VUS uncertainty-that information about such variant is currently unknown. However, between-provider discordance in explanations of the implication of this uncertainty for patients' diagnosis, prognosis, and therapy was a major contributor to the overall experience of uncertainty. Strategies for uncertainty reduction involved periodically checking back for reclassification and receiving concordant and clear recommendation from providers. Other proactive strategies of uncertainty reduction-such as information seeking and reading the genetic test report-were not helpful. Collectively, these findings offer previously unreported insight into uncertainty management strategies used by patients which have the potential to guide clinical management practices.

Patient goals, motivations, and attitudes in a patient-driven variant reclassification study

Family studies to reclassify clinically ascertained variants of uncertain significance (VUS) can impact risk assessment, medical management, and psychological outcomes for patients and their families. There are limited avenues for patients and their families to actively participate in VUS reclassification, and access to family studies at most commercial laboratories is restricted by multiple factors. To explore patient attitudes about participation in family studies for VUS reclassification, we conducted semistructured pre- and post-participation telephone interviews with 38 participants in a family-based VUS reclassification study that utilized a patient-driven approach for family ascertainment and recruitment. Participants had VUS from multigene panel testing performed at multiple clinical laboratories for cancer or other disease risk. Inductive thematic analysis of transcribed interviews highlighted four major themes: (a) Participants' study goals were driven by the desire to resolve uncertainty related to the VUS, (b) Participants had mixed reactions to the VUS reclassification outcomes of the study, (c) Personal, public, and familial knowledge increased through study participation and (d) Participants used study participation to actively cope with the uncertainty of a VUS. As personalized genomic medicine becomes more prevalent, clinicians, clinical laboratories, and researchers could consider creating more opportunities for active partnership with patients and families, who are motivated to contribute data to familial VUS studies.

Reclassification of BRCA1 and BRCA2 variants of uncertain significance: a multifactorial analysis of multicentre prospective cohort

BACKGROUND

BRCA1 and BRCA2 (BRCA1/2) variants classified ambiguously as variants of uncertain significance (VUS) are a major challenge for clinical genetic testing in breast cancer; their relevance to the cancer risk is unclear and the association with the response to specific BRCA1/2-targeted agents is uncertain. To minimise the proportion of VUS in BRCA1/2, we performed the multifactorial likelihood analysis and validated this method using an independent cohort of patients with breast cancer.

METHODS

We used a data set of 2115 patients with breast cancer from the nationwide multicentre prospective Korean Hereditary Breast Cancer study. In total, 83 BRCA1/2 VUSs (BRCA1, n=26; BRCA2, n=57) were analysed. The multifactorial probability was estimated by combining the prior probability with the overall likelihood ratio derived from co-occurrence of each VUS with pathogenic variants, personal and family history, and tumour characteristics. The classification was compared with the interpretation according to the American College of Medical Genetics and Genomics-Association for Molecular Pathology (ACMG/AMP) guidelines. An external validation was conducted using independent data set of 810 patients.

RESULTS

We were able to redefine 38 VUSs (BRCA1, n=10; BRCA2, n=28). The revised classification was highly correlated with the ACMG/AMP guideline-based interpretation (BRCA1, p for trend=0.015; BRCA2, p=0.001). Our approach reduced the proportion of VUS from 19% (154/810) to 8.9% (72/810) in the retrospective validation data set.

CONCLUSION

The classification in this study would minimise the 'uncertainty' in clinical interpretation, and this validated multifactorial model can be used for the reliable annotation of BRCA1/2 VUSs.