Mainstream Model of Genetic Testing for Prostate Cancer at a Large Tertiary Cancer Centre.

BACKGROUND: An estimated 20% to 30% of men with advanced prostate cancer carry a mutation in DNA damage repair genes, of which half are estimated to be germline. Eligibility criteria for germline genetic testing expanded significantly for Ontario patients in May 2021 and many centers adopted a "mainstream" model, defined as oncologist-initiated genetic testing. METHODS: We conducted a retrospective chart review to report on the first-year mainstream experience of a large tertiary oncologic center, the Sunnybrook Odette Cancer Centre. All patients who underwent mainstream at the discretion of their treating physician were included. A subset underwent somatic profiling as part of clinical trial screening. Descriptive statistics were used to report baseline clinicopathologic characteristics and treatments received. RESULTS: Between May 1, 2021, and May 30, 2022, 174 patients with prostate cancer underwent mainstream germline genetic testing with a 19-gene panel. Median age was 75 (IQR 68-80), and 82% of patients were diagnosed with either de novo metastatic or high-risk localized prostate adenocarcinoma. Fourteen patients (8%; 95% CI 4%-12%) were found to have a deleterious germline mutation, including pathogenic or likely pathogenic variants in BRCA1/2, ATM, CHEK2, PMS2, RAD51C, HOXB13, and BRIP1. Forty-nine patients (28%; 95% CI 21%-35%) were found to have a variant of uncertain significance. Thirty-four patients also had next-generation sequencing (NGS) of their somatic tissue. Among this subset, 8 of 34 (23%) had an alteration in homologous recombination repair (HRR) genes. Of the 14 patients with a germline mutation, none had a prior personal history of malignancy and 6 (43%) did not have any first- or second-degree relatives with history of prostate, pancreatic, breast, or ovarian cancer. CONCLUSION: We report on the real-world characteristics of prostate cancer patients who underwent mainstream germline genetic testing. Personal history and family history of cancer cannot reliably stratify patients for the presence of pathogenic germline variants.

A model for the return and referral of all clinically significant secondary findings of genomic sequencing.

Secondary findings (SFs) identified through genomic sequencing (GS) can offer a wide range of health benefits to patients. Resource and capacity constraints pose a challenge to their clinical management; therefore, clinical workflows are needed to optimise the health benefits of SFs. In this paper, we describe a model we created for the return and referral of all clinically significant SFs, beyond medically actionable results, from GS. As part of a randomised controlled trial evaluating the outcomes and costs of disclosing all clinically significant SFs from GS, we consulted genetics and primary care experts to determine a feasible workflow to manage SFs. Consensus was sought to determine appropriate clinical recommendations for each category of SF and which clinician specialist would provide follow-up care. We developed a communication and referral plan for each category of SFs. This involved referrals to specialised clinics, such as an Adult Genetics clinic, for highly penetrant medically actionable findings. Common and non-urgent SFs, such as pharmacogenomics and carrier status results for non-family planning participants, were directed back to the family physician (FP). SF results and recommendations were communicated directly to participants to respect autonomy and to their FPs to support follow-up of SFs. We describe a model for the return and referral of all clinically significant SFs to facilitate the utility of GS and promote the health benefits of SFs. This may serve as a model for others returning GS results transitioning participants from research to clinical settings.

Impact of rapid genetic testing for BRCA1 and BRCA2 at time of breast cancer diagnosis on psychosocial functioning.

PURPOSE: Many women are being offered rapid genetic testing (RGT) for cancer predisposition genes, at the time of breast cancer diagnosis prior to surgery. The goal of this study was to determine if psychosocial functioning was affected in women receiving RGT for BRCA1 and BRCA2 at the time of breast cancer diagnosis. METHODS: Participants were women with invasive breast cancer diagnosed between 2013 and 2018, at four centres in Toronto, Canada. Eligible women were referred into the study by their surgeon at the time of diagnosis. Participants received pre-test genetic counselling and were offered RGT for BRCA1 and BRCA2. Standardized questionnaires (Impact of Event Scale and Hospital Anxiety and Depression Scale) were completed before genetic counselling, and follow-up questionnaires at one-week and one-year post-genetic test result disclosure (higher scores indicate higher symptoms). RESULTS: 1007 women had RGT; 60 women (6.0%) were found to have a BRCA1 or BRCA2 mutation, 80 women (7.9%) had a VUS, and 867 (86.1%) had a negative test result. At one-week post-testing, there were no differences in distress (p = 0.32), anxiety (p = 0.14), or depression (p = 0.42) between women with a BRCA1/2 mutation and those with a negative result. At one year, there were no differences in distress (p = 0.75) or anxiety (p = 0.13) between women with a BRCA1 or BRCA/2 mutation and those with a negative result. However, women with a BRCA1 or BRCA2 mutation had significantly lower depression scores compared to women with a negative result (p = 0.03). CONCLUSION: For women who have RGT for BRCA1 and BRCA2 at the time of breast cancer diagnosis, identifying a BRCA1 or BRCA2 mutation does not impair psychosocial functioning in the short or long term.

Development of patient "profiles" to tailor counseling for incidental genomic sequencing results.

Guidelines recommend that providers engage patients in shared decision-making about receiving incidental results (IR) prior to genomic sequencing (GS), but this can be time-consuming, given the myriad of IR and variation in patients' preferences. We aimed to develop patient profiles to inform pre-test counseling for IR. We conducted semi-structured interviews with participants as a part of a randomized trial of the GenomicsADvISER.com, a decision aid for selecting IR. Interviews explored factors participants considered when deliberating over learning IR. Interviews were analyzed by thematic analysis and constant comparison. Participants were mostly female (28/31) and about half of them were over the age of 50 (16/31). We identified five patient profiles that reflect common contextual factors, attitudes, concerns, and perceived utility of IR. Information Enthusiasts self-identified as "planners" and valued learning most or all IR to enable planning and disease prevention because "knowledge is power". Concerned Individuals defined themselves as "anxious," and were reluctant to learn IR, anticipating negative psychological impacts from IR. Contemplators were discerning about the value and limitations of IR, weighing health benefits with the impacts of not being able to "un-know" information. Individuals of Advanced Life Stage did not consider IR relevant for themselves and primarily considered their implications for family members. Reassurance Seekers were reassured by previous negative genetic test results which shaped their expectations for receiving no IR: "hopefully [GS will] be negative, too. And then I can rest easy". These profiles could inform targeted counseling for IR by providing a framework to address common values, concerns. and misconceptions.