Challenges and Opportunities for Cancer Predisposition Cascade Screening for Hereditary Breast and Ovarian Cancer and Lynch Syndrome in Switzerland: Findings from an International Workshop

Privacy and utility of genetic testing in families with hereditary cancer syndromes living in three countries: the international cascade genetic screening experience

Background: Hereditary breast and ovarian cancer and Lynch syndrome are associated with increased lifetime risk for common cancers. Offering cascade genetic testing to cancer-free relatives of individuals with HBOC or LS is a public health intervention for cancer prevention. Yet, little is known about the utility and value of information gained from cascade testing. This paper discusses ELSI encountered during the implementation of cascade testing in three countries with national healthcare systems: Switzerland, Korea, and Israel. Methods: A workshop presented at the 5th International ELSI Congress discussed implementation of cascade testing in the three countries based on exchange of data and experiences from the international CASCADE cohort. Results: Analyses focused on models of accessing genetic services (clinic-based versus population-based screening), and models of initiating cascade testing (patient-mediated dissemination versus provider-mediated dissemination of testing results to relatives). The legal framework of each country, organization of the healthcare system, and socio-cultural norms determined the utility and value of genetic information gained from cascade testing. Conclusion: The juxtaposition of individual versus public health interests generates significant ELSI controversies associated with cascade testing, which compromise access to genetic services and the utility and value of genetic information, despite national healthcare/universal coverage.

Germline Pathogenic Variant Prevalence Among Latin American and US Hispanic Individuals Undergoing Testing for Hereditary Breast and Ovarian Cancer: A Cross-Sectional Study

PURPOSE

To report on pathogenic germline variants detected among individuals undergoing genetic testing for hereditary breast and/or ovarian cancer (HBOC) from Latin America and compare them with self-reported Hispanic individuals from the United States.

METHODS

In this cross-sectional study, unrelated individuals with a personal/family history suggestive of HBOC who received clinician-ordered germline multigene sequencing were grouped according to the location of the ordering physician: group A, Mexico, Central America, and the Caribbean; group B, South America; and group C, United States with individuals who self-reported Hispanic ethnicity. Relatives who underwent cascade testing were analyzed separately.

RESULTS

Among 24,075 unrelated probands across all regions, most were female (94.9%) and reported a personal history suggestive of HBOC (range, 65.0%-80.6%); the mean age at testing was 49.1 ± 13.1 years. The average number of genes analyzed per patient was highest in group A (A 63 ± 28, B 56 ± 29, and C 40 ± 28). Between 9.1% and 18.7% of patients had pathogenic germline variants in HBOC genes (highest yield in group A), with the majority associated with high HBOC risk. Compared with US Hispanics individuals the overall yield was significantly higher in both Latin American regions (A v C P = 1.64×10-9, B v C P < 2.2×10-16). Rates of variants of uncertain significance were similar across all three regions (33.7%-42.6%). Cascade testing uptake was low in all regions (A 6.6%, B 4.5%, and C 1.9%).

CONCLUSION

This study highlights the importance of multigene panel testing in Latin American individuals with newly diagnosed or history of HBOC, who can benefit from medical management changes including targeted therapies, eligibility to clinical trials, risk-reducing surgeries, surveillance and prevention of secondary malignancy, and genetic counseling and subsequent cascade testing of at-risk relatives.

Risk assessment and genetic counseling for Lynch syndrome - Practice resource of the National Society of Genetic Counselors and the Collaborative Group of the Americas on Inherited Gastrointestinal Cancer

Identifying individuals who have Lynch syndrome involves a complex diagnostic workup that includes taking a detailed family history and a combination of various tests such as immunohistochemistry and/or molecular which may be germline and/or somatic. The National Society of Genetic Counselors and the Collaborative Group of the Americas on Inherited Gastrointestinal Cancer have come together to publish this practice resource for the evaluation of Lynch syndrome. The purpose of this practice resource was to provide guidance and a testing algorithm for Lynch syndrome as well as recommendations on when to offer testing. This practice resource does not replace a consultation with a genetics professional. This practice resource includes explanations in support of this and a summary of background data. While this practice resource is not intended to serve as a review of Lynch syndrome, it includes a discussion of background information and cites a number of key publications which should be reviewed for a more in-depth understanding. This practice resource is intended for genetic counselors, geneticists, gastroenterologists, surgeons, medical oncologists, obstetricians and gynecologists, nurses, and other healthcare providers who evaluate patients for Lynch syndrome.

Using a Tailored Digital Health Intervention for Family Communication and Cascade Genetic Testing in Swiss and Korean Families With Hereditary Breast and Ovarian Cancer: Protocol for the DIALOGUE Study

Background

In hereditary breast and ovarian cancer (HBOC), family communication of genetic test results is essential for cascade genetic screening, that is, identifying and testing blood relatives of known mutation carriers to determine whether they also carry the pathogenic variant, and to propose preventive and clinical management options. However, up to 50% of blood relatives are unaware of relevant genetic information, suggesting that potential benefits of genetic testing are not communicated effectively within family networks. Technology can facilitate communication and genetic education within HBOC families.

Objective

The aims of this study are to develop the K-CASCADE (Korean–Cancer Predisposition Cascade Genetic Testing) cohort in Korea by expanding an infrastructure developed by the CASCADE (Cancer Predisposition Cascade Genetic Testing) Consortium in Switzerland; develop a digital health intervention to support the communication of cancer predisposition for Swiss and Korean HBOC families, based on linguistic and cultural adaptation of the Family Gene Toolkit; evaluate its efficacy on primary (family communication of genetic results and cascade testing) and secondary (psychological distress, genetic literacy, active coping, and decision making) outcomes; and explore its translatability using the reach, effectiveness, adoption, implementation, and maintenance framework.

Methods

The digital health intervention will be available in French, German, Italian, Korean, and English and can be accessed via the web, mobile phone, or tablet (ie, device-agnostic). K-CASCADE cohort of Korean HBOC mutation carriers and relatives will be based on the CASCADE infrastructure. Narrative data collected through individual interviews or mini focus groups from 20 to 24 HBOC family members per linguistic region and 6-10 health care providers involved in genetic services will identify the local cultures and context, and inform the content of the tailored messages. The efficacy of the digital health intervention against a comparison website will be assessed in a randomized trial with 104 HBOC mutation carriers (52 in each study arm). The translatability of the digital health intervention will be assessed using survey data collected from HBOC families and health care providers.

Results

Funding was received in October 2019. It is projected that data collection will be completed by January 2023 and results will be published in fall 2023.

Conclusions

This study addresses the continuum of translational research, from developing an international research infrastructure and adapting an existing digital health intervention to testing its efficacy in a randomized controlled trial and exploring its translatability using an established framework. Adapting existing interventions, rather than developing new ones, takes advantage of previous valid experiences without duplicating efforts. Culturally sensitive web-based interventions that enhance family communication and understanding of genetic cancer risk are timely. This collaboration creates a research infrastructure between Switzerland and Korea that can be scaled up to cover other hereditary cancer syndromes.

Trial Registration

ClinicalTrials.gov NCT04214210; https://clinicaltrials.gov/ct2/show/NCT04214210 and CRiS KCT0005643; https://cris.nih.go.kr/cris/

International Registered Report Identifier (IRRID)

PRR1-10.2196/26264

Sharing genetic test results with family members of BRCA, PALB2, CHEK2, and ATM carriers

OBJECTIVE

This study explored motivators and challenges/barriers to sharing personal genetic test results (GTR) with family members (FM).

METHODS

Semi-structured, in-depth interviews were conducted with 62 women who had a pathogenic or likely pathogenic (P/LP) variant in aBRCA, PALB2, CHEK2, or ATM gene. Selective qualitative data analysis focused on eliciting motivators and challenges/barriers identified by participants when sharing their GTR with FM.

RESULTS

Motivators to sharing personal GTR with FM included: health protection and prevention; moral obligation; decisional empowerment; familial ties; written resources; and contextualization for a familial cause for cancer. Challenges/barriers to family sharing included: concern for FM reactions; complexities of information; lack of closeness; perceived relevance; and emotional impact.

CONCLUSIONS

All motivators and challenges/barriers were identified across BRCA and non-BRCA carriers, demonstrating commonalities in family sharing of GTR among high- to moderate-penetrance hereditary BC (breast cancer) genes. Despite challenges/barriers, participants disclosed their GTR with most close FM, yet restrictions in communication and/or strain on the timing, manner of disclosing, and strategies used varied across certain FM.

PRACTICE IMPLICATIONS

These findings offer healthcare providers and researchers preliminary practical implications for broadly improving family sharing interventions across P/LP variants in BC risk genes by demonstrating important elements to include in family sharing letters.

Genomic Profiling Comparison of Germline BRCA and Non-BRCA Carriers Reveals CCNE1 Amplification as a Risk Factor for Non-BRCA Carriers in Patients With Triple-Negative Breast Cancer

Background: Differences in genomic profiling and immunity-associated parameters between germline BRCA and non-BRCA carriers in TNBC with high tumor burden remain unexplored. This study aimed to compare the differences and explore potential prognostic predictors and therapeutic targets. Methods: The study cohort included 21 consecutive TNBC cases with germline BRCA1/2 mutations and 54 non-BRCA carriers with a tumor size ≥ 2 cm and/or ≥1 affected lymph nodes. Differences in clinicopathological characteristics and genomic profiles were analyzed through next-generation sequencing. Univariate Kaplan-Meier analysis and Cox regression model were applied to survival analysis. Immunohistochemistry was used to confirm the consistency between CCNE1 amplification and cyclin E1 protein overexpression. Results: The cohort included 16 and five patients with germline BRCA1 and BRCA2 mutations, respectively. Patients with germline BRCA1/2 mutations were diagnosed at a significantly younger age and were more likely to have a family history of breast and/or ovarian cancer. Six non-BRCA carriers (11.11%) carried germline mutations in other cancer susceptibility genes, including five mutations in five homologous recombination repair (HRR) pathway genes (9.26%) and one mutation in MSH3 (1.85%). Somatic mutations in HRR pathway genes were found in 22.22 and 14.29% of the non-BRCA and BRCA carriers, respectively. PIK3CA missense mutation (p = 0.046) and CCNE1 amplification (p = 0.2) were found only in the non-BRCA carriers. The median tumor mutation burden (TMB) was 4.1 Muts/Mb, whereas none of the cases had high microsatellite instability (MSI). BRCA status did not affect disease-free survival (DFS, p = 0.15) or overall survival (OS, p = 0.52). CCNE1 amplification was an independent risk factor for DFS in non-BRCA carriers with TNBC (HR 13.07, 95% CI 2.47-69.24, p = 0.003). Consistency between CCNE1 amplification and cyclin E1 protein overexpression was confirmed with an AUC of 0.967 for cyclin E1 signal intensity. Conclusions: We found differences in genetic alterations between germline BRCA and non-BRCA carriers with TNBC and a high tumor burden. TMB and MSI may not be suitable predictors of TNBC for immune checkpoint inhibitors. Notably, CCNE1 amplification is a novel potential prognostic marker and therapeutic target for non-BRCA carriers with TNBC. Cyclin E1 may be used instead of CCNE1 to improve clinical applicability.

Genetic Testing and Surveillance of Young Breast Cancer Survivors and Blood Relatives: A Cluster Randomized Trial

Simple Summary

Identifying breast cancer patients with pathogenic mutations that run in their families may improve the follow-up care they receive and breast cancer screening of their close relatives. In this study we identified breast cancer patients with high chances of having a pathogenic mutation and their close female relatives. We developed and tested two different kinds of letters and booklets that presented either personalized or generic information about screening and breast cancer that runs in families, and we encouraged participants to seek genetic evaluation. We found that both types of letters worked equally well for breast cancer patients and for relatives, regardless of their racial background. The personalized letters had slightly better outcomes. Some breast cancer patients and their relatives used genetic services and improved their screening practices. Black patients and their relatives were more satisfied with the booklets than other participants.

Abstract

We compared a tailored and a targeted intervention designed to increase genetic testing, clinical breast exam (CBE), and mammography in young breast cancer survivors (YBCS) (diagnosed <45 years old) and their blood relatives. A two-arm cluster randomized trial recruited a random sample of YBCS from the Michigan cancer registry and up to two of their blood relatives. Participants were stratified according to race and randomly assigned as family units to the tailored (n = 637) or the targeted (n = 595) intervention. Approximately 40% of participants were Black. Based on intention-to-treat analyses, YBCS in the tailored arm reported higher self-efficacy for genetic services (p = 0.0205) at 8-months follow-up. Genetic testing increased approximately 5% for YBCS in the tailored and the targeted arm (p ≤ 0.001; p < 0.001) and for Black and White/Other YBCS (p < 0.001; p < 0.001). CBEs and mammograms increased significantly in both arms, 5% for YBCS and 10% for relatives and were similar for Blacks and White/Others. YBCS and relatives needing less support from providers reported significantly higher self-efficacy and intention for genetic testing and surveillance. Black participants reported significantly higher satisfaction and acceptability. Effects of these two low-resource interventions were comparable to previous studies. Materials are suitable for Black women at risk for hereditary breast/ovarian cancer (HBOC).

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.

The uptake of predictive DNA testing in 40 families with a pathogenic BRCA1/BRCA2 variant. An evaluation of the proband-mediated procedure

When hereditary breast and ovarian cancer (HBOC) due to a BRCA1/BRCA2 germline pathogenic variant is diagnosed, the proband will be asked to inform other at-risk family members. In the Netherlands, a guideline was introduced in 2012 which provided detailed recommendations regarding this proband-mediated procedure. We now evaluated the uptake of predictive BRCA1/BRCA2 testing in 40 consecutive HBOC families diagnosed in our centre in 2014. We performed a retrospective observational study of all 40 families in which a pathogenic BRCA1/BRCA2 germline variant was identified during 2014. We scored the uptake of predictive and confirmatory testing by the end of 2018 and explored factors associated with the level of uptake. Two families were excluded. In the remaining 38 families, among 239 family members ≥18 years at 50% risk of being a mutation carrier or at 25% risk if the family member at 50% risk was deceased, 102 (43%) were tested. Among 108 females 25-75 years of age at 50% risk, 59 (55%) underwent predictive or confirmatory testing, and among 43 males at 50% risk with daughters ≥18 years, 22 (51%) were tested. Factors which complicated cascade screening included family members living abroad, probands not wanting to share information and limited pedigree information. In conclusion, the standard proband-mediated procedure of informing relatives seems to be far from optimal. We suggest a tailored approach for each family, including the option of a direct approach to at-risk family members by the geneticist. In addition, we suggest detailed monitoring and follow-up of families.