According to the Princess Margaret Cancer Centre, in the next five years, as many as 100,000 individuals in Ontario will undergo screenings for genetic conditions that elevate their risk of hereditary cancers and a condition linked to high cholesterol and heart disease.
Described by the hospital as one of the largest population genomics studies in Canada, this initiative merges screening outcomes to enable participants and their healthcare providers to make informed decisions that could potentially delay, mitigate, or prevent cancer and heart disease. Concurrently, researchers at the hospital will gather a comprehensive dataset that they can analyze alongside patient data, which may assist in addressing health disparities.
The initial participants will be cancer patients at the hospital who may possess genetic risks impacting their treatment or monitoring strategies, stated Dr. Raymond Kim, medical director of cancer early detection at Princess Margaret.
“While these patients are diagnosed with cancer, their genetic profiles remain unknown,” Kim explained. “Understanding their genetic information helps determine if we—meaning the doctors—need to be vigilant about other cancer types.”
Awareness of individuals’ genetic profiles can signal doctors about potential risks and guide subsequent treatment options, Kim noted. For instance, those with BRCA mutations are advised to begin breast monitoring at age 20. If a person has a gene variant linked to Lynch syndrome, which is associated with colorectal and other cancers, they may require regular colonoscopies, he mentioned.
Leslie Born, a patient involved in a previous research initiative at the hospital, was diagnosed with advanced ovarian cancer in March 2020, which had metastasized to her stomach lining. She underwent surgery followed by chemotherapy.
Leslie Born is seen during chemotherapy treatment. Born had no strong immediate family history of cancer, but she was screened for a variety of mutations associated with cancer. (Submitted by Leslie Born)
Although Born had no significant family history of cancer, she was tested for multiple mutations related to cancer.
“I found out I had a BRCA2 genetic mutation after my surgery and the biopsy results came back,” Born recalled. “It was quite a shock. I had no idea.”
The BRCA2 gene is responsible for producing a protein that functions as a tumor suppressor. Individuals with a BRCA2 mutation are at an increased risk for certain cancers, such as breast, ovarian, prostate, pancreatic, and melanoma.
Born now undergoes an annual breast MRI and mammogram as part of her monitoring regimen. Without this genomic information, she and her doctors would be unaware of this necessity, Kim emphasized.
Expanding Access to Genetic Testing
Laura Palma, a certified genetic counselor at McGill University Health Centre in Montreal, who is not involved in the project, noted that smaller family sizes today compared to previous generations can lead to traditional methods of identifying high-risk families missing many individuals.
“Some of these families are not easily identifiable,” Palma remarked. “Expanding access to genetic testing could be the most effective approach moving forward.”
Palma expressed interest in seeing the outcomes of the project and how participants respond to the information, such as altering dietary habits or levels of physical activity.
The genomic testing and subsequent care will incur costs, and Palma indicated that the cost-effectiveness will not be immediately evident.
“We need studies in Canada to determine whether our system can accommodate a model like this and whether it is beneficial for taxpayers,” Palma stated.
After genetic testing revealed two Saskatchewan sisters had a mutation that increased their chances of developing a deadly type of stomach cancer, they face agonizing decisions to save their lives.
Jenna Scott, co-director of the master’s program in genetic counseling at the University of British Columbia, echoed Palma’s sentiments and praised the “fantastic” initiative.
According to Scott, the expense of genomic testing has decreased and has become more user-friendly, such as utilizing mouthwash instead of blood samples to obtain DNA. However, she also raised concerns regarding the broader implementation of the project while considering cultural contexts.
“If I’m an Indigenous patient residing in a remote rural area, how can I access a breast MRI? Is there funding available to assist me in reaching the urban centers where screenings are performed?” she questioned.
The researchers aim to share the findings with the participants and intend to use the data gathered to evaluate the effectiveness of this extensive screening approach and identify the target population. Kim aspires to enroll not only patients from Toronto’s University Health Network but also those referred by their family physicians.
Family members of patients, including individuals with familial hypercholesterolemia, an inherited disorder linked to high cholesterol and cardiovascular risks, will be provided with counseling, monitoring, and personalized treatment options when necessary, Kim stated.
Helix, a biotechnology firm based in San Mateo, California, is collaborating on the project. Kim noted that the hospital’s research ethics board has worked diligently to safeguard individuals’ privacy.
