Development of a comprehensive approach to adult hereditary cancer testing in Ontario.

BACKGROUND: Genetic testing for hereditary cancer susceptibility has advanced over time due to the discovery of new risk genes, improved technology and decreased cost. In the province of Ontario, testing eligibility criteria were initially developed to include hereditary breast, ovarian and colorectal cancer syndromes. The rapid evolution of genetic technologies has facilitated the ability to interrogate a large number of genes concurrently. This, coupled with new knowledge about risk genes, necessitated a coordinated approach to expanding the scope of genes and indications tested and synchronisation of access and test utilisation across the province as required in a publicly funded universal healthcare system. METHODS: Ontario Health-Cancer Care Ontario convened expert working groups to develop a standardised and comprehensive cancer gene list for adults and accompanying hereditary cancer testing (HCT) criteria using an evidence-based framework and broad laboratory and clinical genetics engagement. RESULTS: A standardised 76-cancer-gene panel, organised into 13 larger disease site panels and 25 single/small gene panels, was developed and endorsed by the working groups. Provincial genetic testing eligibility criteria were updated to align with the new panels and to guide clinical decision-making. In the first year following the implementation of these changes, 10 564 HCT panels were performed with an overall mutation detection rate of 12.2%. CONCLUSION: Using an evidence framework and broad clinical engagement to develop and endorse an updated guidance document, cancer genetic testing for adults in Ontario is now standardised and coordinated across the province.

Stay at home: implementation and impact of virtualising cancer genetic services during COVID-19.

The COVID-19 pandemic has led to the rapid adoption of virtual clinic processes and healthcare delivery. Herein, we examine the impact of virtualising genetics services at Canada's largest cancer centre. A retrospective review was conducted to evaluate relevant metrics during the 12 weeks prior to and during virtual care, including referral and clinic volumes, patient wait times and genetic testing uptake. The number of appointments and new patients seen were maintained during virtual care. Likewise, there was a significant increase in the number of patients offered testing during virtual care who did not provide a blood sample (176/180 (97.7%) vs 180/243 (74.1%); p<0.001), and a longer median time from the date of pretest genetic counselling to the date a sample was given (0 vs 11 days; p<0.001). Referral volumes significantly decreased during virtual care (35 vs 22; p<0.001), which was accompanied by a decreased median wait time for first appointment (55 days vs 30 days; p<0.001). The rapid virtualisation of cancer genetic services allowed the genetics clinic to navigate the COVID-19 pandemic without compromising clinical volumes or access to genetic testing. There was a decrease in referral volumes and uptake of genetic testing, which may be attributable to pandemic-related clinical restrictions.

Psychological and health behaviour outcomes following multi-gene panel testing for hereditary breast and ovarian cancer risk: a mini-review of the literature.

INTRODUCTION: Knowledge of the genetic mechanisms driving hereditary breast and ovarian cancer (HBOC) has recently expanded due to advances in gene sequencing technologies. Genetic testing for HBOC risk now involves multi-gene panel testing, which includes well characterized high-penetrance genes (e.g. BRCA1 and BRCA2), as well as moderate- and low-penetrance genes. Certain moderate and low penetrance genes are associated with limited data to inform cancer risk estimates and clinical management recommendations, which create new sources of genetic and clinical uncertainty for patients. PURPOSE: The aim of this review is to evaluate the psychological and health behaviour outcomes associated with multi-gene panel testing for HBOC risk. The search was developed in collaboration with an Information Specialist (Princess Margaret Cancer Centre) and conducted in the following databases: MEDLINE, EMBASE, EMCare, PsycINFO, Epub Ahead of Publication. RESULTS: Similar to the BRCA1/2 literature, individuals with a pathogenic variant (PV) reported higher levels of testing-related concerns and cancer-specific distress, as well as higher uptake of prophylactic surgery in both affected and unaffected individuals compared to those with variant of uncertain significance (VUS) or negative result. A single study demonstrated that individuals with a PV in a moderate penetrance gene reported higher rates of cancer worry, genetic testing concerns and cancer-related distress when compared to women with high penetrance PV. Analysis of cancer screening and prevention outcomes based upon gene penetrance were limited to two studies, with conflicting findings. CONCLUSION: The findings in this review emphasize the need for studies examining psychological and health behavior outcomes associated with panel testing to include between group differences based upon both variant pathogenicity and gene penetrance. Future studies evaluating the impact of gene penetrance on patient-reported and clinical outcomes will require large samples to be powered for these analyses given that a limited number of tested individuals are found to have a PV.

The Canadian genetic counseling workforce: Perspectives from employers and recent graduates.

There is a lack of literature devoted to the Canadian genetic counseling workforce. Current and prospective genetic counseling students, graduates, employers, programs, and funding agencies remain largely uninformed of trends in the job market. The purpose of this study was to investigate the employment experiences of recent Canadian genetic counseling graduates and employers of genetic counselors (GCs) in Canada. An online survey was distributed to Canadians who had graduated from North American genetic counseling programs from 2014 to 2018 and to employers with experience hiring patient-facing genetic counselors from 2016 to 2018. Quantitative data were analyzed through descriptive statistics and, where appropriate, logistic regression. Qualitative data were reviewed to illustrate and support the quantitative data. Half of the employer responders (11/22) reported hiring more or many more genetic counselors compared to 3 years ago (2016), and a majority (n = 19, 86%) reported a desire to hire at least one more genetic counselor if funding were available. Most graduates (45/70, 64%) reported securing employment before graduation, 33% (n = 23) within 6 months of graduation, and no one taking longer than 1 year. For recent graduates, location was the most important factor when looking for work, and those who chose to work in Canada experienced significantly more challenges gaining employment as opposed to those who worked internationally (p = 0.03). The specialties in highest demand for genetic counselors and the most common areas of practice for recent graduates included adult general genetics, prenatal genetics, and cancer genetics. Overall, our findings suggest that there is a growth of employment opportunities in Canada and more employer-reported need for clinical genetic counselors; however, there is a lack of funding to support this expansion.

Oncologist-led germline genetic testing for uveal melanoma.

PURPOSE: To report the genotype and phenotype of a cohort of unselected uveal melanoma (UM) patients who had germline multi-gene panel genetic testing, including the BAP1 gene, from a large multi-ethnic cancer centre. We describe the central role of the medical genetics clinic in collaboration with oncologists in a mainstreaming model to facilitate genetic testing, counselling and streamlining of patients with hereditary cancer predisposition. METHODS: A retrospective chart review of clinical and genetic findings of unselected UM patients who had germline genetic testing between December 2019 and October 2021 was conducted. Extracted DNA from peripheral blood samples were analyzed with a multi-gene panel that included at least six genes associated with hereditary melanoma. The correlation between the genotype and the phenotype of the cohort was evaluated. Statistical analysis comprised descriptive and comparative statistics with significance assigned at p < .05. The genetics clinic streamlined patients among the relevant oncology clinics for cancer screening in germline BAP1 positive individuals. RESULTS: In unselected UM patients, 3.5% (4/114) tested positive for a BAP1 pathogenic variant. Germline BAP1 status was associated with a family history of mesothelioma (p = .0015) and metastatic disease (p = .017). There were no other significant associations between the patient- or tumour-related characteristics and germline BAP1 results. CONCLUSION: A germline BAP1 mutation was detected in 3.5% of unselected UM patients. The oncologist-initiated and genetics-led mainstreaming model is a straightforward process and can be utilized for offering genetic testing to all UM patients.

Absence of Calcitriol Causes Increased Lactational Bone Loss and Lower Milk Calcium but Does Not Impair Post-lactation Bone Recovery in Cyp27b1 Null Mice.

We hypothesized that adaptation to calcium supply demands of pregnancy and lactation do not require calcitriol. Adult Cyp27b1 null mice lack calcitriol and have hypocalcemia, hypophosphatemia, and rickets. We studied wild-type (WT) and null sister pairs raised on a calcium-, phosphorus-, and lactose-enriched "rescue" diet that prevents hypocalcemia and rickets. Bone mineral content (BMC) increased >30% in pregnant nulls, declined 30% during lactation, and increased 30% by 4 weeks post-weaning. WT showed less marked changes. Micro-CT revealed loss of trabecular bone and recovery in both genotypes. In lactating nulls, femoral cortical thickness declined >30%, whereas endocortical perimeter increased; both recovered to baseline after weaning; there were no such changes in WT. Histomorphometry revealed a profound increase in osteoid surface and thickness in lactating nulls, which recovered after weaning. By three-point bend test, nulls had a >50% decline in ultimate load to failure that recovered after weaning. Although nulls showed bone loss during lactation, their milk calcium content was 30% lower compared with WT. Serum parathyroid hormone (PTH) was markedly elevated in nulls at baseline, reduced substantially in pregnancy, but increased again during lactation and remained high post-weaning. In summary, pregnant Cyp27b1 nulls gained BMC with reduced secondary hyperparathyroidism, implying increased intestinal calcium delivery. Lactating nulls lost more bone mass and strength than WT, accompanied by increased osteoid, reduced milk calcium, and worsened secondary hyperparathyroidism. This implies suboptimal intestinal calcium absorption. Post-weaning, bone mass and strength recovered to baseline, whereas BMC exceeded baseline by 40%. In conclusion, calcitriol-independent mechanisms regulate intestinal calcium absorption and trabecular bone metabolism during pregnancy and post-weaning but not during lactation; calcitriol may protect cortical bone during lactation. © 2017 American Society for Bone and Mineral Research.