Improving Access to Hereditary Testing in Pancreatic Ductal Carcinoma.

PURPOSE: Approximately 5%-10% of patients with pancreatic ductal adenocarcinoma (PDAC) have an inherited basis, yet uptake of genetic testing remains low and subject to disparities. This study compared two genetic testing pathways available to patients referred to a provincial cancer center, BC Cancer: a traditional hereditary cancer clinic-initiated testing (HCT) pathway and a new oncology clinic-initiated testing (OCT) pathway. METHODS: Study subjects were patients with confirmed PDAC referred for genetic testing through the HCT or OCT pathway between June 1, 2020, and February 1, 2022. Charts were retrospectively reviewed for patient characteristics and testing outcomes. RESULTS: The study population was 397 patients (HCT, n = 279 and OCT, n = 118). OCT patients were more likely to have non-European ethnicity compared with HCT patients (41.9% v 25.6%, P = .004), to have earlier-stage disease (P = .012), and to have better Eastern Cooperative Oncology Group performance status than the HCT group (P = .001). A total of 306 patients completed testing (77%). OCT patients had higher test completion rates than HCT patients (odds ratio, 3.74 [95% CI, 1.66 to 9.62]). Median time for results was shorter in OCT than in HCT (53 days [IQR, 44-76] v 107 days [IQR, 63.8-158.3]). Pancreatic cancer susceptibility pathogenic gene variants were identified in 8.5% (26/306). CONCLUSION: The real-world observations in our study show that oncology clinic-initiated hereditary testing is more effective and faster than testing through hereditary cancer clinic referrals and reaches a more ethnically diverse population. This has important implications for publicly funded environments with limited resources for genetic counseling.

Patient ethnicity and cascade genetic testing: a descriptive study of a publicly funded hereditary cancer program.

Cascade genetic testing for hereditary cancer is highly accurate and cost-effective for identifying individuals at high risk for cancer; however, not all eligible people utilize this service. While sociodemographic factors related to the uptake of cascade genetic testing, such as age and sex, have been fairly well described in the literature, there is limited data available regarding patient ethnicity. We analyzed four years of testing data for this factor, as well as sex, age and genes tested. The patients were seen by the Hereditary Cancer Program of BC Cancer, which serves the entire population of British Columbia and Yukon, Canada. Patient ethnicity was compared to the 2016 Census data from the same region. Fisher's exact test was conducted to explore the cascade genetic testing uptakes. Chi-square test was used to compare the major ethnicity groups to Census data. There was significant variability in the uptake of cascade genetic testing in the three largest population groups (p < 0.05), with individuals of European ethnic origin overrepresented, individuals of Asian ethnic origin modestly underrepresented, and individuals of North American Indigenous origin considerably underrepresented for cascade genetic testing. The proportions represented compared to those expected from census data were significantly different for these three largest groups (p < 0.01). The majority of cascade genetic tests were for BRCA1/BRCA2 (58.8%), followed by 16.9% for Lynch syndrome genes. Most patients were female (70%), and the mean age of patients was 49 years old. This study provides further insight into uptake of cascade genetic testing by patient ethnicity. Examining patient ethnicity and cascade genetic testing rates helps to identify underserved populations. Our analysis highlights significant underrepresentation of North American Indigenous individuals for hereditary cancer cascade genetic testing, and helps recognize the need for development of culturally-safe alternatives to outreach and service promotion.

Integrating Tumor Sequencing Into Clinical Practice for Patients With Mismatch Repair-Deficient Lynch Syndrome Spectrum Cancers.

INTRODUCTION: Uninformative germline genetic testing presents a challenge to clinical management for patients suspected to have Lynch syndrome, a cancer predisposition syndrome caused by germline variants in the mismatch repair (MMR) genes or EPCAM. METHODS: Among a consecutive series of MMR-deficient Lynch syndrome spectrum cancers identified through immunohistochemistry-based tumor screening, we investigated the clinical utility of tumor sequencing for the molecular diagnosis and management of suspected Lynch syndrome families. MLH1-deficient colorectal cancers were prescreened for BRAF V600E before referral for genetic counseling. Microsatellite instability, MLH1 promoter hypermethylation, and somatic and germline genetic variants in the MMR genes were assessed according to an established clinical protocol. RESULTS: Eighty-four individuals with primarily colorectal (62%) and endometrial (31%) cancers received tumor-normal sequencing as part of routine clinical genetic assessment. Overall, 27% received a molecular diagnosis of Lynch syndrome. Most of the MLH1-deficient tumors were more likely of sporadic origin, mediated by MLH1 promoter hypermethylation in 54% and double somatic genetic alterations in MLH1 (17%). MSH2-deficient, MSH6-deficient, and/or PMS2-deficient tumors could be attributed to pathogenic germline variants in 37% and double somatic events in 28%. Notably, tumor sequencing could explain 49% of cases without causal germline variants, somatic MLH1 promoter hypermethylation, or somatic variants in BRAF. DISCUSSION: Our findings support the integration of tumor sequencing into current Lynch syndrome screening programs to improve clinical management for individuals whose germline testing is uninformative.

Genetic testing in families with hereditary colorectal cancer in British Columbia and Yukon: a retrospective cross-sectional analysis.

BACKGROUND: Genetic testing in families with hereditary cancer enables identification of people most likely to benefit from intensive screening and preventive measures; however, the uptake of testing in relatives (known as cascade carrier testing) for hereditary colorectal cancer syndromes has been shown to be low. Our objective was to report rates of familial testing for hereditary colorectal cancer syndromes in a publicly funded hereditary cancer clinic in Canada. METHODS: A cross-sectional retrospective database review was used to determine testing uptake between 1997 and 2016 for families served by the provincial Hereditary Cancer Program for British Columbia and Yukon. Analyses were conducted for genes associated with syndromes with an increased risk for colorectal cancer, including Lynch syndrome (MLH1, MSH2, MSH6, PMS2 and EPCAM) and familial adenomatous polyposis (APC), and for additional moderate- to high-penetrance genes (STK11, TP53, SMAD4, MUTYH, PTEN and CHEK2). Descriptive statistics were used and all analyses were 2-tailed. RESULTS: The study cohort included 245 index patients, with carrier testing performed in 382 relatives. The mean age at family member testing was 41.2 years, and most (61.0%) of the family members who underwent testing were women. The median time between disclosure of index cases and their family member's results was 8.3 months. Among eligible first-degree relatives, 32.6% (268/821) underwent testing in BC. Of 67 cancer diagnoses in family members, most (62.7%) occurred before genetic testing. INTERPRETATION: A substantial proportion of people at risk for hereditary colorectal cancer do not undergo genetic testing. This gap highlights the need to explore barriers to testing and to consider interventions to promote uptake; more aggressive efforts by hereditary cancer programs are needed to reach this highest risk population.

Evaluating the impact of universal Lynch syndrome screening in a publicly funded healthcare system.

PURPOSE: Referrals for Lynch syndrome (LS) assessment have traditionally been based on personal and family medical history. The introduction of universal screening practices has allowed for referrals based on immunohistochemistry tests for mismatch repair (MMR) protein expression. This study aims to characterize the effect of universal screening in a publicly funded healthcare system with comparison to patients referred by traditional criteria, from January 2012 to March 2017. METHODS: Patient files from the time of initiation of universal screening from 2012 to 2017 were reviewed. Patients were sorted into two groups: (a) universally screened and (b) referred by traditional methods. Mutation detection rates, analysis of traditional testing criteria met, and cascade carrier testing were evaluated. RESULTS: The mutation detection rate of the universal screening group was higher than the traditionally referred group (45/228 (19.7%) vs 50/390 (12.5%), P = .05), though each were able to identify unique patients. An analysis of testing criteria met by each patient showed that half of referred patients from the universal screening group could not meet any traditional testing criteria. CONCLUSION: The implementation of universal screening in a publicly funded system will increase efficiency in detecting patients with LS. The resources available for genetic testing and counseling may be more limited in public systems, thus inclusion of secondary screening with BRAF and MLH1 promoter hypermethylation testing is key to further optimizing efficiency.

Employability of genetic counselors with a PhD in genetic counseling.

The development of a PhD in genetic counseling has been discussed for more than 20 years, yet the perspectives of employers have not been assessed. The goal of this qualitative study was to gain an understanding of the employability of genetic counselors with a PhD in genetic counseling by conducting interviews with United States employers of genetic counselors. Study participants were categorized according to one of the following practice areas: academic, clinical, government, industry, laboratory, or research. All participants were responsible for hiring genetic counselors in their institutions. Of the 30 employers interviewed, 23 envisioned opportunities for individuals with a PhD degree in genetic counseling, particularly in academic and research settings. Performing research and having the ability to be a principal investigator on a grant was the primary role envisioned for these individuals by 22/30 participants. Employers expect individuals with a PhD in genetic counseling to perform different roles than MS genetic counselors with a master's degree. This study suggests there is an employment niche for individuals who have a PhD in genetic counseling that complements, and does not compete with, master's prepared genetic counselors.

Career research interests and training of genetic counseling students.

Research is important to validate clinical services, provide information on the effectiveness of practice techniques, and develop the knowledge base of a clinical profession. Genetic counseling students from American Board of Genetic Counseling (ABGC) accredited training programs were surveyed to determine their career research interests and interest in pursuing a hypothetical doctoral degree in genetic counseling. Genetic counseling program directors were surveyed to assess the emphasis on research training within their programs. A substantial number (46%, n = 92) of genetic counseling students are interested in performing research in their careers and many (40%, n = 80) would pursue a doctoral degree in genetic counseling if it was available. Students and directors from programs with a thesis requirement reported a significantly higher emphasis on career research preparation than those from programs without a thesis requirement. The results of this study indicate that future genetic counselors are interested in contributing to the research base that will advance the field. This study suggests a need to strengthen research training within ABGC accredited graduate programs and explore the development of a doctoral degree option in genetic counseling.