Coming of age in Canada: a study of population-based genetic testing for breast and ovarian cancer

Interest in genetic testing and risk-reducing behavioral changes: results from a community health assessment in New York City

Risk-based genetic tests are often used to determine cancer risk, when to initiate screening, and frequency of screening, but rely on interest in genetic testing. We examined overall interest in genetic testing for cancer risk assessment and willingness to change behavior, and whether these are affected by demographic or socioeconomic factors.We conducted a community needs health survey in 2019 among primary care and cancer patients, family members and community members in New York City. We used univariable analysis and relative risk regression to examine interest in genetic cancer risk testing and willingness to modify lifestyle behaviors in response to an informative genetic test.Of the 1225 participants, 74.0% (n = 906) expressed interest in having a genetic test to assess cancer risk. Interest in genetic testing was high across all demographic and socioeconomic groups; reported interest in genetic testing by group ranged from 65.0 (participants aged 65 years and older) to 83.6% (participants below federal poverty level). Among the 906 participants that reported interest in genetic testing, 79.6% were willing to change eating habits, 66.5% to change exercise habits, and 49.5% to lose weight in response to an informative genetic test result.Our study reveals that interest in genetic testing for cancer risk is high among patients and community members and is high across demographic and socioeconomic groups, as is the reported willingness to change behavior. Based on these results, we recommend that population-based genetic testing may result in greater reduction cancer risk, particularly among minoritized groups.

Patient Experience with a Gynecologic Oncology-Initiated Genetic Testing Model for Women with Tubo-Ovarian Cancer

Background: Up to 20% of women diagnosed with tubo-ovarian carcinoma carry a germline pathogenic variant in a cancer-predisposing gene (e.g., BRCA1/BRCA2). Identifying these variants can help to inform eligibility for therapies, guide surveillance and prevention of new primary cancers, and assess risk to family members. The Gynecologic Oncology-Initiated Genetic Testing Model (GOIGT) was initiated at the McGill University Health Centre (MUHC) to streamline universal germline genetic testing for this population, while addressing the limited resources in the public healthcare system. This study aimed to evaluate the patient experience of participating in this model. Methods: Study participants were patients diagnosed with high-grade non-mucinous epithelial tubo-ovarian cancer who underwent genetic testing through the GOIGT model between 1 January 2017 and 31 December 2020. Eligible participants completed the retrospective questionnaires at least one month after result disclosure. Results: A total of 126 patients were tested through the GOIGT model during the study period, of which 56 were invited to participate. Thirty-four participants returned the study questionnaire. Overall, participants did not report decision regret following the genetic testing and were satisfied with the GOIGT model. Participants reported low levels of uncertainty and distress related to the implications of their test results for themselves and their family members. Conclusions: The results of this study support the continued implementation of mainstreamed genetic testing models for women with high-grade non-mucinous tubo-ovarian cancer. Further studies are required to compare experiences for patients with different genetic test results.

Genetic Testing for All: Overcoming Disparities in Ovarian Cancer Genetic Testing

Nearly 3% of the population carries genetic variants that lead to conditions that include hereditary breast and ovarian cancer and Lynch syndrome. These pathogenic variants account for approximately 20% of ovarian cancer cases, and those with germline pathogenic variants have an odds ratio between 4 and 40 for developing ovarian cancer compared with noncarriers. Given the high prevalence of genetic variants, multiple organizations, including ASCO, recommend universal genetic counseling and testing for women diagnosed with epithelial ovarian cancer. Unfortunately, most individuals with a hereditary ovarian cancer syndrome are unaware of their underlying mutation, and racial and ethnic minority individuals as well as patients of low socioeconomic status experience disproportionate rates of underrecognition, leading to late and missed diagnoses. In this article, we review the current understanding of disparities in genetic testing for people with ovarian cancer, the role of population-based genetic testing, and innovative strategies to overcome the critical inequities present in current cancer genetic medicine. Underuse and disparities related to accessing recommended genetic services are complex and multifactorial, requiring improvements in processes related to provider identification, genetic counseling and testing referral, and patient uptake/adherence. Through the expansion of remote genetic counseling, offering online strategies for genetic testing, and reaching at-risk relatives through direct relative contact cascade testing and population-based genetic testing, there are a growing number of innovations in the field of genetic medicine, many of which emphasize health equity and offer promising alternatives to the current paradigm of genetic testing.

Psychological Distress and Quality of Life in Participants Undergoing Genetic Testing for Arrhythmogenic Right Ventricular Cardiomyopathy Caused by TMEM43 p.S358L: Is It Time to Offer Population-Based Genetic Screening?

PURPOSE

We have identified 27 families in Newfoundland and Labrador (NL) with the founder variant TMEM43 p.S358L responsible for 1 form of arrhythmogenic right ventricular cardiomyopathy. Current screening guidelines rely solely on cascade genetic screening, which may result in unrecognized, high-risk carriers who would benefit from preemptive implantable cardioverter-defibrillator therapy. This pilot study explored the acceptability among subjects to TMEM43 p.S358L population-based genetic screening (PBGS) in this Canadian province.

METHODS

A prospective cohort study assessed attitudes, psychological distress, and health-related quality of life (QOL) in unselected individuals who underwent genetic screening for the TMEM43 p.S358L variant. Participants (n = 73) were recruited via advertisements and completed 2 surveys at baseline, 6 months, and 1 year which measured health-related QOL (SF-36v2) and psychological distress (Impact of Events Scale).

RESULTS

No variant-positive carriers were identified. Of those screened through a telephone questionnaire, >95% felt positive about population-genetic screening for TMEM43 p.S358L, though 68% reported some degree of anxiety after seeing the advertisement. There were no significant changes in health-related QOL or psychological distress scores over the study period.

CONCLUSION

Despite some initial anxiety, we show support for PBGS among research subjects who screened negative for the TMEM43 p.S358L variant in NL. These findings have implications for future PBGS programs in the province.

Towards population-based genetic screenings for breast and ovarian cancer: A comprehensive review from economic evaluations to patient perspectives

Genetic testing for hereditary breast and ovarian cancer following genetic counseling is based on guidelines that take into account particular features of the personal and family history, and clinical criteria conferring a probability of having a BRCA mutation greater than 10% as a threshold for accessing the test. However, besides reducing mortality and social impact, the extension of screening programs also for healthy family members would allow a huge saving of the rising costs associated with these pathologies, supporting the choice of the "Test" strategy versus a "No Test" one. Analyses of different health care systems show that by applying the "Test" strategy on patients and their families, a decrease in breast and ovarian cancer cases is achieved, as well as a substantial decrease in costs of economic resources, including the costs of the clinical management of early detected tumors. In this review, we analyzed the most recent papers published on this topic and we summarized the findings on the economic evaluations related to breast and ovarian cancer population screenings. These results proved and validated that the population-wide testing approach is a more accurate screening and preventive intervention than traditional guidelines based on personal/family history and clinical criteria to reduce breast and ovarian cancer risk.

Prevalence and Spectrum of Germline BRCA1 and BRCA2 Variants of Uncertain Significance in Breast/Ovarian Cancer: Mysterious Signals From the Genome

About 10–20% of breast/ovarian (BC/OC) cancer patients undergoing germline BRCA1/2 genetic testing have been shown to harbor Variants of Uncertain Significance (VUSs). Since little is known about the prevalence of germline BRCA1/2 VUS in Southern Italy, our study aimed at describing the spectrum of these variants detected in BC/OC patients in order to improve the identification of potentially high-risk BRCA variants helpful in patient clinical management. Eight hundred and seventy-four BC or OC patients, enrolled from October 2016 to December 2020 at the “Sicilian Regional Center for the Prevention, Diagnosis and Treatment of Rare and Heredo-Familial Tumors” of University Hospital Policlinico “P. Giaccone” of Palermo, were genetically tested for germline BRCA1/2 variants through Next-Generation Sequencing analysis. The mutational screening showed that 639 (73.1%) out of 874 patients were BRCA-w.t., whereas 67 (7.7%) were carriers of germline BRCA1/2 VUSs, and 168 (19.2%) harbored germline BRCA1/2 pathogenic/likely pathogenic variants. Our analysis revealed the presence of 59 different VUSs detected in 67 patients, 46 of which were affected by BC and 21 by OC. Twenty-one (35.6%) out of 59 variants were located on BRCA1 gene, whereas 38 (64.4%) on BRCA2. We detected six alterations in BRCA1 and two in BRCA2 with unclear interpretation of clinical significance. Familial anamnesis of a patient harboring the BRCA1-c.3367G>T suggests for this variant a potential of pathogenicity, therefore it should be carefully investigated. Understanding clinical significance of germline BRCA1/2 VUS could improve, in future, the identification of potentially high-risk variants useful for clinical management of BC or OC patients and family members.

Expanding the search for germline pathogenic variants for breast cancer. How far should we go and how high should we jump? The missed opportunity!

Since the identification of BRCA1 and BRCA2 genes 3 decades ago, genetic testing and genetic counseling have become an integral part of routine clinical practice. The risk of breast cancer among carriers of germline pathogenic variants, like BRCA1 and BRCA2, is well established. Risk-reducing interventions, including bilateral mastectomies and salpingo-oophorectomies are both effective and have become more acceptable. Many researchers and professional societies view current guidelines as restrictive and may miss many at-risk women, and are calling to expand testing to include all patients with breast cancer, regardless of their personal or family history of cancer, while others are calling for wider adoption to even include all healthy women at age 30 or older. This review will address expanding testing in two directions; horizontally to include more patients, and even healthy women, and vertically to include more genes using next-generation sequencing-based multi-gene panel testing.

Identifying Ashkenazi Jewish BRCA1/2 founder variants in individuals who do not self-report Jewish ancestry

Current guidelines recommend BRCA1 and BRCA2 genetic testing for individuals with a personal or family history of certain cancers. Three BRCA1/2 founder variants - 185delAG (c.68_69delAG), 5382insC (c.5266dupC), and 6174delT (c.5946delT) - are common in the Ashkenazi Jewish population. We characterized a cohort of more than 2,800 research participants in the 23andMe database who carry one or more of the three Ashkenazi Jewish founder variants, evaluating two characteristics that are typically used to recommend individuals for BRCA testing: self-reported Jewish ancestry and family history of breast, ovarian, prostate, or pancreatic cancer. Of the 1,967 carriers who provided self-reported ancestry information, 21% did not self-report Jewish ancestry; of these individuals, more than half (62%) do have detectable Ashkenazi Jewish genetic ancestry. In addition, of the 343 carriers who provided both ancestry and family history information, 44% did not have a first-degree family history of a BRCA-related cancer and, in the absence of a personal history of cancer, would therefore be unlikely to qualify for clinical genetic testing. These findings may help inform the discussion around broader access to BRCA genetic testing.

Hereditary Breast and Ovarian Cancer in Families from Southern Italy (Sicily)-Prevalence and Geographic Distribution of Pathogenic Variants in BRCA1/2 Genes

Recent advances in the detection of germline pathogenic variants (PVs) in BRCA1/2 genes have allowed a deeper understanding of the BRCA-related cancer risk. Several studies showed a significant heterogeneity in the prevalence of PVs across different populations. Because little is known about this in the Sicilian population, our study was aimed at investigating the prevalence and geographic distribution of inherited BRCA1/2 PVs in families from this specific geographical area of Southern Italy. We retrospectively collected and analyzed all clinical information of 1346 hereditary breast and/or ovarian cancer patients genetically tested for germline BRCA1/2 PVs at University Hospital Policlinico "P. Giaccone" of Palermo from January 1999 to October 2019. Thirty PVs were more frequently observed in the Sicilian population but only some of these showed a specific territorial prevalence, unlike other Italian and European regions. This difference could be attributed to the genetic heterogeneity of the Sicilian people and its historical background. Therefore hereditary breast and ovarian cancers could be predominantly due to BRCA1/2 PVs different from those usually detected in other geographical areas of Italy and Europe. Our investigation led us to hypothesize that a higher prevalence of some germline BRCA PVs in Sicily could be a population-specific genetic feature of BRCA-positive carriers.

Population-based genetic testing for Women's cancer prevention

Germline mutations in cancer-susceptibility-genes (CSG) can dramatically increase womens' lifetime risk of ovarian, endometrial, breast and bowel cancers. Identification of unaffected carriers is important to enable proactive engagement with highly effective screening and preventive options to minimise cancer risk. Currently, a family-history model is used to identify individuals with CSGs. Complex regional referral guidelines specify the family-history criteria required before an individual is eligible for genetic-testing. This model is ineffective, resource intense, misses >50% CSG carriers, is associated with underutilisation of genetic-testing services and delays detection of mutation carriers. Although awareness and detection of CSG-carriers has improved, over 97% carriers remain unidentified. This reflects significant missed opportunities for precision-prevention. Population-based genetic-testing (PBGT) represents a novel healthcare strategy with the potential to dramatically improve detection of unaffected CSG-carriers along with enabling population risk-stratification for cancer precision-prevention. Several research studies have assessed the impact, feasibility, acceptability, long-term psychological outcomes and cost-effectiveness of population-based BRCA-testing in the Ashkenazi-Jewish population. Initial data on PBGT in the general-population is beginning to emerge and large implementation studies investigating PBGT in the general-population are needed. This review will summarise the current research into the clinical, psycho-social, health-economic, societal and ethical consequences of a PBGT model for women's cancer precision-prevention.

Germline Genetic Testing for Breast Cancer Risk: The Past, Present, and Future

The field of germline genetic testing for breast cancer (BC) risk has evolved substantially in the last decade. The introduction of multigene panel testing (MGPT) led to an urgent need to understand the cancer risk associated with several genes included in the panels. Although the research on understanding the cancer risk associated with mutations in several genes continues, there is also a need to understand the modifying effects of race and ethnicity, family history, and BC pathology on the prevalence of germline mutations and associated BC risk. Furthermore, polygenic risk scores (PRSs) to predict BC risk in patients with or without germline mutations in cancer-predisposition genes are now available for clinical use, although data on the clinical utility of PRSs are lacking. In patients with advanced BC associated with BRCA1/2 mutation, olaparib and talazoparib are now approved for treatment. In addition, molecular profiling studies are being used to clarify the BC tumor biology in mutation carriers to identify potential therapeutic options. In this article, we discuss these advances in the field of germline genetic testing and highlight current limitations and implications for clinical care.