Population-based BRCA1/2 testing programmes are highly acceptable in the Jewish community: results of the JeneScreen Study.

BACKGROUND: Ashkenazi Jewish (AJ) people have a higher incidence of BRCA1/2 pathogenic variants (PVs) than unselected populations. Three BRCA-Jewish founder mutations (B-JFMs) comprise >90% of BRCA1/2 PVs in AJ people. Personal/family cancer history-based testing misses ≥50% of people with B-JFM. METHODS: We compared two population-based B-JFM screening programmes in Australia-using (1) an online tool (Sydney) and (2) in-person group sessions (Melbourne). RESULTS: Of 2167 Jewish people tested (Sydney n=594; Melbourne n=1573), 1.3% (n=28) have a B-JFM, only 2 of whom had a significant cancer family history (Manchester score ≥12). Pretest anxiety scores were normal (mean 9.9±3.5 (6-24)), with no significant post-result change (9.5±3.3). Decisional regret (mean 7.4±13.0 (0-100)), test-related distress (mean 0.8+/2.2 (0-30)) and positive experiences (reverse-scored) (mean 3.4±4.5 (1-20)) scores were low, with no significant differences between Sydney and Melbourne participants. Post-education knowledge was good overall (mean 11.8/15 (±2.9)) and significantly higher in Melbourne than Sydney. Post-result knowledge was the same (mean 11.7 (±2.4) vs 11.2 (±2.4)). Participants with a B-JFM had higher post-result anxiety and test-related distress and lower positive experiences, than those without a B-JFM, but scores were within the normal range. Family cancer history did not significantly affect knowledge or anxiety, or pretest perception of B-JFM or cancer risks. Most participants (93%) were satisfied/very satisfied with the programme. CONCLUSION: Both B-JFM screening programmes are highly acceptable to Australian Jewish communities. The programme enabled identification of several individuals who were previously unaware they have a B-JFM, many of whom would have been ineligible for current criteria-based testing in Australia.

Aligning organisational priorities and implementation science for cancer research.

BACKGROUND: The challenge of implementing evidence into routine clinical practice is well recognised and implementation science offers theories, models and frameworks to promote investigation into delivery of evidence-based care. Embedding implementation researchers into health systems is a novel approach to ensuring research is situated in day-to-day practice dilemmas. To optimise the value of embedded implementation researchers and resources, the aim of this study was to investigate stakeholders' views on opportunities for implementation science research in a cancer setting that holds potential to impact on care. The research objectives were to: 1) Establish stakeholder and theory informed organisation-level implementation science priorities and 2) Identify and prioritise a test case pilot implementation research project. METHODS: We undertook a qualitative study using semi-structured interviews. Participants held either a formal leadership role, were research active or a consumer advocate and affiliated with either a specialist cancer hospital or a cancer alliance of ten hospitals. Interview data were summarised and shared with participants prior to undertaking both thematic analysis, to identify priority areas for implementation research, and content analysis, to identify potential pilot implementation research projects. The selected pilot Implementation research project was prioritised using a synthesis of an organisational and implementation prioritisation framework - the organisational priority setting framework and APEASE framework. RESULTS: Thirty-one people participated between August 2022 and February 2023. Four themes were identified: 1) Integration of services to address organisational priorities e.g., tackling fragmented services; 2) Application of digital health interventions e.g., identifying the potential benefits of digital health interventions; 3) Identification of potential for implementation research, including deimplementation i.e., discontinuing ineffective or low value care and; 4) Focusing on direct patient engagement e.g., wider consumer awareness of the challenges in delivering cancer care. Six potential pilot implementation research projects were identified and the EMBED project, to support clinicians to refer appropriate patients with cancer for genetic testing, was selected using the synthesised prioritisation framework. CONCLUSIONS: Using a theory informed and structured approach the alignment between strategic organisational priorities and implementation research priorities can be identified. As a result, the implementation research focus can be placed on activities with the highest potential impact.

Calibrating variant curation by clinical context based on factors that influence patients' tolerance of uncertainty.

PURPOSE: Shared decision making manages genomic uncertainty by integrating molecular and clinical uncertainties with patient values to craft a person-centered management plan. Laboratories seek genomic report consistency, agnostic to clinical context. Molecular reports often mask laboratory-managed uncertainties from clinical decision making. Better integration of these uncertainty management strategies requires a nuanced understanding of patients' perceptions and reactions to test uncertainties. We explored patients' tolerance to variant uncertainty in 3 parameters: (1) relative causal significance, (2) risk accuracy, and (3) classification validity. METHOD: Deliberative forums were undertaken with 18 patients with predictive testing experience. Uncertainty deliberations were elicited for each parameter. A thematic framework was first developed, and then mapped to whether they justified tolerance to more or less parameter-specific uncertainty. RESULTS: Six identified themes mapped to clinical and personal domains. These domains generated opposing forces when calibrating uncertainty. Personal themes justified tolerance of higher uncertainty and clinical themes lower uncertainty. Decision making in uncertainty focused on reducing management regret. Open communication increased tolerance of classification validity and risk accuracy uncertainty. Using these data, we have developed a nascent clinical algorithm integrating molecular uncertainty with clinical context through a targeted communication framework. CONCLUSION: Maximizing test utility necessitates context-specific recalibration of uncertainty management and communication.

Heterogeneity in how women value risk-stratified breast screening.

PURPOSE: Risk-stratified screening has potential to improve the cost effectiveness of national breast cancer screening programs. This study aimed to inform a socially acceptable and equitable implementation framework by determining what influences a woman's decision to accept a personalized breast cancer risk assessment and what the relative impact of these key determinants is. METHODS: Multicriteria decision analysis was used to elicit the relative weights for 8 criteria that women reported influenced their decision. Preference heterogeneity was explored through cluster analysis. RESULTS: The 2 criteria valued most by the 347 participants related to program access, "Mode of invitation" and "Testing process". Both criteria significantly influenced participation (P < .001). A total of 73% preferred communication by letter/online. Almost all women preferred a multidisease risk assessment with potential for a familial high-risk result. Four preference-based subgroups were identified. Membership to the largest subgroup was predicted by lower educational attainment, and women in this subgroup were concerned with program access. Higher relative perceived breast cancer risk predicted membership to the smallest subgroup that was focused on test parameters, namely "Scope of test" and "Test specificity". CONCLUSION: Overall, Australian women would accept a personalized multidisease risk assessment, but when aligning with their preferences, it will necessitate a focus on program access and the development of online communication frameworks.

The predicted effect and cost-effectiveness of tailoring colonoscopic surveillance according to mismatch repair gene in patients with Lynch syndrome.

PURPOSE: Lynch syndrome-related colorectal cancer (CRC) risk substantially varies by mismatch repair (MMR) gene. We evaluated the health impact and cost-effectiveness of MMR gene-tailored colonoscopic surveillance. METHODS: We first estimated sex- and MMR gene-specific cumulative lifetime risk of first CRC without colonoscopic surveillance using an optimization algorithm. Next, we harnessed these risk estimates in a microsimulation model, "Policy1-Lynch," and compared 126 colonoscopic surveillance strategies against no surveillance. RESULTS: The most cost-effective strategy was 3-yearly surveillance from age 25 to 70 years (pathogenic variants [path_] in MLH1 [path_MLH1], path_MSH2) with delayed surveillance for path_MSH6 (age 30-70 years) and path_PMS2 (age 35-70 years) heterozygotes (incremental cost-effectiveness ratio = Australian dollars (A) $8,833/life-year saved). This strategy averted 60 CRC deaths (153 colonoscopies per death averted) over the lifetime of 1000 confirmed patients with Lynch syndrome (vs no surveillance). This also reduced colonoscopies by 5% without substantial change in health outcomes (vs nontailored 3-yearly surveillance from 25-70 years). Generally, starting surveillance at age 25 (vs 20) years was more cost-effective with minimal effect on life-years saved and starting 5 to 10 years later for path_MSH6 and path_PMS2 heterozygotes (vs path_MLH1 and path_MSH2) further improved cost-effectiveness. Surveillance end age (70/75/80 years) had a minor effect. Three-yearly surveillance strategies were more cost-effective (vs 1 or 2-yearly) but prevented 3 fewer CRC deaths. CONCLUSION: MMR gene-specific colonoscopic surveillance would be effective and cost-effective.

Real world outcomes and implementation pathways of exome sequencing in an adult genetic department.

PURPOSE: This study aimed to correlate the indications and diagnostic yield of exome sequencing (ES) in adult patients across various clinical settings. The secondary aim was to examine the clinical utility of ES in adult patients. METHODS: Data on demographics, clinical indications, results, management changes, and cascade testing were collected for 250 consecutive patients who underwent ES through an adult genetics department between 2016 and 2021. Data were analyzed using descriptive and inferential statistics. Testing in which traditional gene panels were in standard use, such as in heritable cancers, was excluded. RESULTS: The average age at testing was 43 years (range = 17-80 years). A molecular diagnosis was identified in 29% of patients. Older age at symptom onset did not pre-exclude a substantial diagnostic yield. Patients with syndromic intellectual disability and multiple system disorders had the highest yield. In >50% of patients with an exome diagnosis, the results changed management. Cascade testing occured in at least one family member for 30% of patients with a diagnosis. Diagnostic results had reproductive implications for 26% of patients and 31% of patients' relatives. CONCLUSION: ES has a robust diagnostic yield and clear clinical utility in adult patients across a range of ages and phenotypes.

Implementing gene curation for hereditary cancer susceptibility in Australia: achieving consensus on genes with clinical utility.

BACKGROUND: The strength of evidence supporting the validity of gene-disease relationships is variable. Hereditary cancer has the additional complexity of low or moderate penetrance for some confirmed disease-associated alleles. METHODS: To promote national consistency in interpretation of hereditary cancer/tumour gene test results, we requested opinions of representatives from Australian Family Cancer Clinics regarding the clinical utility of 157 genes initially collated for a national research project. Viewpoints were sought by initial survey, face-to-face workshop and follow-up survey. Subsequent review was undertaken by the eviQ Cancer Genetics Reference Committee, a national resource providing evidence-based and consensus-driven cancer treatment protocols. RESULTS: Genes were categorised by clinical actionability as: relevant for testing on presentation of common cancer/tumour types (n=45); relevant for testing in the context of specific rare phenotypes (n=74); insufficient clinical utility (n=34) or contentious clinical utility (n=3). Opinions for several genes altered during the study time frame, due to new information. CONCLUSION: Through an iterative process, consensus was achieved on genes with clinical utility for hereditary cancer/tumour conditions in the Australian setting. This study highlighted need for regular review of gene-disease lists, a role assumed in Australia for hereditary cancer/tumour predisposition genes by the eviQ Cancer Genetics Reference Committee.

Clinical impact of genomic testing in patients with suspected monogenic kidney disease.

PURPOSE: To determine the diagnostic yield and clinical impact of exome sequencing (ES) in patients with suspected monogenic kidney disease. METHODS: We performed clinically accredited singleton ES in a prospectively ascertained cohort of 204 patients assessed in multidisciplinary renal genetics clinics at four tertiary hospitals in Melbourne, Australia. RESULTS: ES identified a molecular diagnosis in 80 (39%) patients, encompassing 35 distinct genetic disorders. Younger age at presentation was independently associated with an ES diagnosis (p < 0.001). Of those diagnosed, 31/80 (39%) had a change in their clinical diagnosis. ES diagnosis was considered to have contributed to management in 47/80 (59%), including negating the need for diagnostic renal biopsy in 10/80 (13%), changing surveillance in 35/80 (44%), and changing the treatment plan in 16/80 (20%). In cases with no change to management in the proband, the ES result had implications for the management of family members in 26/33 (79%). Cascade testing was subsequently offered to 40/80 families (50%). CONCLUSION: In this pragmatic pediatric and adult cohort with suspected monogenic kidney disease, ES had high diagnostic and clinical utility. Our findings, including predictors of positive diagnosis, can be used to guide clinical practice and health service design.

What Happens After Menopause? (WHAM): A prospective controlled study of cardiovascular and metabolic risk 12 months after premenopausal risk-reducing bilateral salpingo-oophorectomy.

OBJECTIVE: To prospectively measure cardiometabolic risk 12 months after premenopausal risk-reducing bilateral salpingo-oophorectomy (RRBSO) compared to a similar age comparison group, and the effects of Hormone Therapy (HT) on cardiometabolic risk. METHODS: Prospective observational study of 95 premenopausal women planning RRBSO and 99 comparisons who retained their ovaries. At baseline and 12 months, blood pressure (BP), Body Mass Index (BMI), waist and hip circumference, fasting total, HDL and LDL cholesterol, triglycerides, high-sensitivity C-reactive protein, glucose and insulin were measured and HOMA-IR was calculated. Chi-square tests, t-tests and adjusted logistic regression models were used to compare groups. RESULTS: Baseline cardiometabolic phenotypes were similar between groups but more RRBSO participants were overweight/obese with higher waist/hip ratios. By 12 months, BP and cardiometabolic phenotypes were largely unchanged. Paired t-tests showed statistically significant increases in BMI (p = 0.037) and weight (p = 0.042) and larger increases in waist circumference (p < 0.001) and waist-hip ratio (p = 0.009) after RRBSO vs comparisons. However, these were not significant when adjusted for baseline values. After RRBSO 60% initiated Hormone Therapy (HT). Paired t-tests demonstrated that non-HT users had a significantly greater mean increase in waist circumference of 4.3 cm (95% CI 2.0-6.5) compared to 1.3 cm in HT users (95% CI -0.2-2.7, p < 0.001), which remained significant when adjusted for baseline values (p = 0.02). At 12 months, mean waist circumference was 2.94 cm greater in non-HT users compared to HT users. CONCLUSIONS: Cardiometabolic risk markers are largely unchanged 12 months after RRBSO. Hormone Therapy after RRBSO may prevent against an increase in waist circumference.

What happens after menopause? (WHAM): A prospective controlled study of vasomotor symptoms and menopause-related quality of life 12 months after premenopausal risk-reducing salpingo-oophorectomy.

OBJECTIVE: To measure menopausal symptoms and quality of life up to 12 months after risk-reducing salpingo-oophorectomy (RRSO) and to measure the effects of hormone therapy. METHODS: Prospective observational study of 95 premenopausal women planning RRSO and a comparison group of 99 who retained their ovaries. Vasomotor symptoms and menopausal-related quality of life (QoL) were measured by the Menopause-Specific QoL Intervention scale at baseline, 3, 6 and 12 months. Chi-square tests measured differences in prevalence of vasomotor symptoms between RRSO vs the comparison group and by hormone therapy use. Change in QoL were examined with multilevel modelling. RESULTS: Three months after RRSO hot flush prevalence increased from 5.3% to 56.2% and night sweats from 20.2% to 47.2%. Symptoms did not worsen between 3 and 12 months and remained unchanged in the comparison group (p<0.001). After RRSO, 60% commenced hormone therapy. However, 40% of hormone therapy uses continued to experience vasomotor symptoms. After RRSO, 80% of non-hormone therapy users reported vasomotor symptoms. Regardless of hormone therapy use, 86% categorized their vasomotor symptoms as "mild" after RRSO. Following RRSO, Menopause-related QoL deteriorated but was stable in the comparison group (adjusted coefficient = 0.75, 95%CI = 0.55-0.95). After RRSO, QoL was better in hormone therapy users vs non-users (adjusted coefficient = 0.49, 95%CI = 0.20-0.78). CONCLUSIONS: Vasomotor symptoms increase by 3 months after RRSO but do not worsen over the next 12 months. Hormone Therapy reduces but does not resolve vasomotor symptoms and may improve QoL, but not to pre-oophorectomy levels.

What happens after menopause? (WHAM): A prospective controlled study of sleep quality up to 12 months after premenopausal risk-reducing salpingo-oophorectomy.

OBJECTIVE: Sleep difficulties impair function and increase the risk of depression at menopause and premenopausal oophorectomy may further worsen sleep. However, prospective data are limited, and it remains uncertain whether Hormone Therapy (HT) improves sleep. This prospective observational study measured sleep quality before and up to 12 months after risk-reducing salpingo-oophorectomy (RRSO) compared to a similar age comparison group who retained their ovaries. METHODS: Ninety-five premenopausal women undergoing RRSO and 99 comparisons were evaluated over a 12-month period using the Pittsburgh Sleep Quality Index (PSQI). RESULTS: Almost half reported poor sleep quality at baseline. Overall sleep quality was not affected by RRSO until 12 months (p = 0.007). However, sleep disturbance increased by 3 months and remained significantly elevated at 12 months (p < 0.001). Trajectory analysis demonstrated that 41% had increased sleep disturbance after RRSO which persisted in 17.9%. Risk factors for sleep disturbance included severe vasomotor symptoms, obesity and smoking. Around 60% initiated HT after RRSO. Sleep quality was significantly better in HT users vs non users (p = 0.020) but HT did not restore sleep quality to baseline levels. CONCLUSIONS: Overall sleep quality is not affected by RRSO, but new onset sleep disturbance is common, particularly in those with severe vasomotor symptoms. Clinicians should be alert to new-onset sleep disturbance and the potential for HT to improve sleep quality.

Impact of national guidelines on use of BRCA1/2 germline testing, risk management advice given to women with pathogenic BRCA1/2 variants and uptake of advice.

BACKGROUND: This nationwide study assessed the impact of nationally agreed cancer genetics guidelines on use of BRCA1/2 germline testing, risk management advice given by health professionals to women with pathogenic BRCA1/2 variants and uptake of such advice by patients. METHODS: Clinic files of 883 women who had initial proband screens for BRCA1/2 pathogenic variants at 12 familial cancer clinics between July 2008-July 2009 (i.e. before guideline release), July 2010-July 2011 and July 2012-July 2013 (both after guideline release) were audited to determine reason given for genetic testing. Separately, the clinic files of 599 female carriers without a personal history of breast/ovarian cancer who underwent BRCA1/2 predictive genetic testing and received their results pre- and post-guideline were audited to ascertain the risk management advice given by health professionals. Carriers included in this audit were invited to participate in a telephone interview to assess uptake of advice, and 329 agreed to participate. RESULTS: There were no significant changes in the percentages of tested patients meeting at least one published indication for genetic testing - 79, 77 and 78% of files met criteria before guideline, and two-, and four-years post-guideline, respectively (χ = 0.25, p = 0.88). Rates of documentation of post-test risk management advice as per guidelines increased significantly from pre- to post-guideline for 6/9 risk management strategies. The strategies with the highest compliance amongst carriers or awareness post-release of guidelines were annual magnetic resonance imaging plus mammography in women 30-50 years (97%) and annual mammography in women > 50 years (92%). Of women aged over 40 years, 41% had a risk-reducing bilateral mastectomy. Amongst women aged > 40 years, 75% had a risk-reducing salpingo-oophorectomy. Amongst women who had not had a risk-reducing bilateral mastectomy, only 6% took risk-reducing medication. Fear of side-effects was cited as the main reasons for not taking these medicines by 73% of women. CONCLUSIONS: Guidelines did not change the percentages of tested patients meeting genetic testing criteria but improved documentation of risk management advice by health professionals. Effective approaches to enhance compliance with guidelines are needed to improve risk management and quality of care.

A homozygous truncating variant in GDF9 in siblings with primary ovarian insufficiency.

Premature or primary ovarian insufficiency (POI) affects approximately 1% of women and can be due to a variety of causes. Genetic causes include syndromic and non-syndromic POI. There are several promising candidate genes for whom a clear Mendelian association with non-syndromic POI has not yet been conclusively established, including GDF9. GDF9 is an oocyte-secreted factor and is part of the TGF-beta superfamily of morphogens. It has an important role in follicular development and granulosa cell maturation. We report the case of two siblings with primary ovarian insufficiency (POI) and a homozygous truncating variant in GDF9 (c.604C>T; p.(Gln202*). This report helps establish a clear gene-disease association between GDF9 and POI and argues for routine evaluation for GDF9 variants in patients undergoing genomic investigation for POI.

Cost-effectiveness of long-term clinical management of BRCA pathogenic variant carriers.

PURPOSE: Women who inherit a BRCA1 or BRCA2 pathogenic variant are at high risk of developing breast and ovarian cancer. Evidence for the effectiveness and cost-effectiveness of long-term management in clinical practice is lacking. The purpose of this study was to evaluate the real-world cost-effectiveness of BRCA carrier management within a structured clinical program. METHODS: Lifetime health outcomes and costs of clinical management for female unaffected BRCA carriers aged 20 were measured using a microsimulation model. For the intervention, women could attend a high-risk clinic, undergo risk-reducing surgery, and receive annual breast screening. Input data for the model was from a clinical database of 983 BRCA carriers. The comparator was no risk management. Outcomes were discounted at 5%. RESULTS: The incremental cost-effectiveness ratio for the program was $32,359 to $48,263 per quality-adjusted life-year (QALY). Limiting uptake of risk-reducing salpingo-oophorectomy to <50% of carriers decreased cost-effectiveness by $7000-8000 per QALY. Achieving perfect adherence to guidelines was less cost-effective for BRCA2 due to increased risk-reducing mastectomy costs with smaller incremental health benefit. CONCLUSION: Long-term management of BRCA carriers within a structured clinical program is cost-effective. Suboptimal adherence to risk management guidelines can substantially affect outcomes and is an important consideration for future studies.

Germline whole exome sequencing of a family with appendiceal mucinous tumours presenting with pseudomyxoma peritonei.

BACKGROUND: Familial cases of appendiceal mucinous tumours (AMTs) are extremely rare and the underlying genetic aetiology uncertain. We identified potential predisposing germline genetic variants in a father and daughter with AMTs presenting with pseudomyxoma peritonei (PMP) and correlated these with regions of loss of heterozygosity (LOH) in the tumours. METHODS: Through germline whole exome sequencing, we identified novel heterozygous loss-of-function (LoF) (i.e. nonsense, frameshift and essential splice site mutations) and missense variants shared between father and daughter, and validated all LoF variants, and missense variants with a Combined Annotation Dependent Depletion (CADD) scaled score of ≥10. Genome-wide copy number analysis was performed on tumour tissue from both individuals to identify regions of LOH. RESULTS: Fifteen novel variants in 15 genes were shared by the father and daughter, including a nonsense mutation in REEP5. None of these germline variants were located in tumour regions of LOH shared by the father and daughter. Four genes (EXOG, RANBP2, RANBP6 and TNFRSF1B) harboured missense variants that fell in a region of LOH in the tumour from the father only, but none showed somatic loss of the wild type allele in the tumour. The REEP5 gene was sequenced in 23 individuals with presumed sporadic AMTs or PMP; no LoF or rare missense germline variants were identified. CONCLUSION: Germline exome sequencing of a father and daughter with AMTs identified novel candidate predisposing genes. Further studies are required to clarify the role of these genes in familial AMTs.

The predicted impact and cost-effectiveness of systematic testing of people with incident colorectal cancer for Lynch syndrome.

OBJECTIVES: To evaluate the health impact and cost-effectiveness of systematic testing for Lynch syndrome (LS) in people with incident colorectal cancer (CRC) in Australia. DESIGN, SETTING, PARTICIPANTS: We investigated the impact of LS testing strategies in a micro-simulation model (Policy1-Lynch), explicitly modelling the cost of testing all patients diagnosed with incident CRC during 2017, with detailed modelling of outcomes for patients identified as LS carriers (probands) and their at-risk relatives throughout their lifetimes. For people with confirmed LS, we modelled ongoing colonoscopic surveillance. MAIN OUTCOME MEASURES: Cost-effectiveness of six universal tumour testing strategies (testing for DNA mismatch repair deficiencies) and of universal germline gene panel testing of patients with incident CRC; impact on cost-effectiveness of restricting testing by age at CRC diagnosis (all ages, under 50/60/70 years) and of colonoscopic surveillance interval (one, two years). RESULTS: The cost-effectiveness ratio of universal tumour testing strategies (annual colonoscopic surveillance, no testing age limit) compared with no testing ranged from $28 915 to $31 904/life-year saved (LYS) (indicative willingness-to-pay threshold: $30 000-$50 000/LYS). These strategies could avert 184-189 CRC deaths with an additional 30 597-31 084 colonoscopies over the lifetimes of 1000 patients with incident CRC with LS and 1420 confirmed LS carrier relatives (164-166 additional colonoscopies/death averted). The most cost-effective strategy was immunohistochemistry and BRAF V600E testing (incremental cost-effectiveness ratio [ICER], $28 915/LYS). Universal germline gene panel testing was not cost-effective compared with universal tumour testing strategies (ICER, $2.4 million/LYS). Immunohistochemistry and BRAF V600E testing was cost-effective at all age limits when paired with 2-yearly colonoscopic surveillance (ICER, $11 525-$32 153/LYS), and required 4778-15 860 additional colonoscopies to avert 46-181 CRC deaths (88-103 additional colonoscopies/death averted). CONCLUSIONS: Universal tumour testing strategies for guiding germline genetic testing of people with incident CRC for LS in Australia are likely to be cost-effective compared with no testing. Universal germline gene panel testing would not currently be cost-effective.

Insights into sudden cardiac death: exploring the potential relevance of non-diagnostic autopsy findings.

AIMS: Unexplained sudden cardiac death (SCD) may be attributable to cardiogenetic disease. Presence or absence of autopsy anomalies detected following premature sudden death direct appropriate clinical evaluation of at-risk relatives towards inherited cardiomyopathies or primary arrhythmia syndromes, respectively. We investigated the relevance of non-diagnostic pathological abnormalities of indeterminate causality (uncertain) such as myocardial hypertrophy, fibrosis, or inflammatory infiltrates to SCD. METHODS AND RESULTS: At-risk relatives of unexplained SCD cases aged 1-64 years without prior cardiac disease (n = 98) with either normal and negative (40%, true sudden arrhythmic death syndrome; SADS) or isolated non-diagnostic (60%, uncertain sudden unexplained death; SUD) cardiac histological autopsy findings at a central forensic pathology unit were referred to the regional unexplained SCD clinic for clinical cardiac phenotyping. Uncertain SUD were older than true SADS cases (31.8 years vs. 21.1 years, P < 0.001). A cardiogenetic diagnosis was established in 24 families (24.5%) following investigation of 346 referred relatives. The proportions of uncertain SUD and true SADS explained by familial cardiogenetic diagnoses were similar (20% vs. 31%, P = 0.34, respectively), with primary arrhythmia syndromes predominating. Unexplained SCD cases were more likely than matched non-cardiac premature death controls to demonstrate at least one uncertain autopsy finding (P < 0.001). CONCLUSION: Primary arrhythmia syndromes predominate as familial cardiogenetic diagnoses amongst both uncertain SUD and true SADS cases. Non-diagnostic or uncertain histological findings associate with SUD, though cannot be attributed a causative status. At-risk relatives of uncertain SUD cases should be evaluated for phenotypic evidence of both ion channel disorders and cardiomyopathies.

A cost-effectiveness model of genetic testing and periodical clinical screening for the evaluation of families with dilated cardiomyopathy.

PURPOSE: To assess the relative cost-effectiveness of cascade genetic testing in asymptomatic relatives of patients with dilated cardiomyopathy (DCM) compared with periodical clinical surveillance. METHODS: A decision-analytic model, combining a decision tree and a Markov model, was used to determine the lifetime costs and quality-adjusted life years (QALYs) for the two strategies. Deterministic and probabilistic sensitivity analyses were undertaken to assess the robustness of findings and to explore decision uncertainty. RESULTS: The incremental cost per additional QALY of cascade genetic testing prior to periodical clinical surveillance of first-degree relatives compared with periodical clinical surveillance alone was estimated at approximately AUD $6100. At established thresholds of cost-effectiveness, there is a 90% probability that cascade genetic testing is cost-effective. Extensive sensitivity analyses, including the addition of second-degree relatives, did not alter the conclusions drawn from the main analysis. CONCLUSION: Using cascade genetic testing to guide clinical surveillance of asymptomatic relatives of patients with DCM is very likely to be cost-effective. As the DCM pathogenic variant detection rate rises and new evidence for personalized treatment of at-risk individuals becomes available, the cost-effectiveness of cascade testing will further increase.

Population-based genetic testing of asymptomatic women for breast and ovarian cancer susceptibility.

PURPOSE: The identification of carriers of hereditary breast and ovarian cancer (HBOC) gene variants through family cancer history alone is suboptimal, and most population-based genetic testing studies have been limited to founder mutations in high-risk populations. Here, we determine the clinical utility of identifying actionable variants in a healthy cohort of women. METHODS: Germline DNA from a subset of healthy Australian women participating in the lifepool project was screened using an 11-gene custom sequencing panel. Women with clinically actionable results were invited to attend a familial cancer clinic (FCC) for post-test genetic counseling and confirmatory testing. Outcomes measured included the prevalence of pathogenic variants, and the uptake rate of genetic counseling, risk reduction surgery, and cascade testing. RESULTS: Thirty-eight of 5908 women (0.64%) carried a clinically actionable pathogenic variant. Forty-two percent of pathogenic variant carriers did not have a first-degree relative with breast or ovarian cancer and 89% pursued referral to an FCC. Forty-six percent (6/13) of eligible women pursued risk reduction surgery, and the uptake rate of cascade testing averaged 3.3 family members per index case. CONCLUSION: Within our cohort, HBOC genetic testing was well accepted, and the majority of high-risk gene carriers identified would not meet eligibility criteria for genetic testing based on their existing family history.

An alternative approach to establishing unbiased colorectal cancer risk estimation in Lynch syndrome.

PURPOSE: Biallelic pathogenic variants in the mismatch repair (MMR) genes cause a recessive childhood cancer predisposition syndrome known as constitutional mismatch repair deficiency (CMMRD). Family members with a heterozygous MMR variant have Lynch syndrome. We aimed at estimating cancer risk in these heterozygous carriers as a novel approach to avoid complicated statistical methods to correct for ascertainment bias. METHODS: Cumulative colorectal cancer incidence was estimated in a cohort of PMS2- and MSH6-associated families, ascertained by the CMMRD phenotype of the index, by using mutation probabilities based on kinship coefficients as analytical weights in a proportional hazard regression on the cause-specific hazards. Confidence intervals (CIs) were obtained by bootstrapping at the family level. RESULTS: The estimated cumulative colorectal cancer risk at age 70 years for heterozygous PMS2 variant carriers was 8.7% (95% CI 4.3-12.7%) for both sexes combined, and 9.9% (95% CI 4.9-15.3%) for men and 5.9% (95% CI 1.6-11.1%) for women separately. For heterozygous MSH6 variant carriers these estimates are 11.8% (95% CI 4.5-22.7%) for both sexes combined, 10.0% (95% CI 1.83-24.5%) for men and 11.7% (95% CI 2.10-26.5%) for women. CONCLUSION: Our findings are consistent with previous reports that used more complex statistical methods to correct for ascertainment bias. These results underline the need for MMR gene-specific surveillance protocols for Lynch syndrome.