Early cancer detection using circulating tumour DNA enabled by whole genome sequencing of primary solid tumours

Improving early detection for people with cancer predisposition syndromes

The earlier a cancer is caught, the better the chances it can be effectively treated. In fact, studies have found that 90 per cent of people diagnosed with Stage I cancers survive at least five years after their initial diagnosis, while for those diagnosed at Stage IV, this number sadly drops to less than 20 per cent.

In this context, having effective methods to detect cancer early is extremely important. This is particularly the case in people with genetic cancer predisposition syndromes, who have an increased lifetime risk of developing multiple cancers and should therefore be continuously monitored to catch early signs of disease. 

But that doesn’t always happen. For some cancers like pancreatic and ovarian, there are no effective early detection protocols, and for others, existing detection protocols tend to be cumbersome and often involve expensive tests that require patients to travel to large cancer centres. To reduce the burden of these protocols and improve outcomes for patients with hereditary cancer syndromes, a new pan-Canadian research team funded by the Marathon of Hope Cancer Centres Network is working to develop a blood test that could be deployed as a screening mechanism to improve early cancer detection for these individuals.

“Our goal is to improve early cancer detection among high-risk patients,” says team lead Dr. Trevor Pugh (University Health Network). “By providing a simple and accessible screening tool, we can improve early diagnosis and ensure patients receive timely, life-saving treatments.”

This minimally invasive test, also known as a liquid biopsy, analyzes tiny fragments of DNA circulating in the bloodstream, which can reveal early signs of cancer. Network funding will allow the team to do whole genome sequencing of tumour samples from hereditary cancer patients, which can then be used to improve the efficacy of these tests.

“By sequencing tumours from cancer predisposition carriers, we can identify unique features of their cancers and determine whether these markers are detectable in blood samples. This will allow us to improve the sensitivity and accuracy of our blood test,” says Dr. Pugh.

The study is part of the cfDNA in Hereditary And High Risk Malignancies (CHARM) initiative, which unites eight genetics clinics across seven provinces. The project’s multidisciplinary team includes Dr. Raymond Kim (UHN), Dr. Lesa Dawson (Eastern Health), Dr. Intan Schrader (BC Cancer), and Dr. Yvonne Bombard (Unity Health). Together, they aim to transform how hereditary cancer patients are monitored, reducing the burden of intensive screening and making early detection more accessible.

“The development of a blood test that can detect multiple cancers early has the potential to significantly improve patient outcomes,” says Dr. Pugh.