The PATHFINDER 2 study enrolled more than 35,000 participants at U.S. institutions; The Princess Margaret was the only non-U.S. site, contributing data from 1,500 healthy volunteers.
Led locally by Dr. Raymond Kim, Cl inician Scientist and Medical Director of the Cancer Early Detection Program and Bhalwani Familial Cancer Clinic, the study evaluated a Multi-Cancer Early Detection (MCED) blood test that can ident ify up to 50 types of cancer - including pancreatic, liver, and head and neck cancers, which currently have no routine screening options.
Developed by U.S.-based company GRAIL, Inc., the test detects fragments of tumour DNA circulat ing in the blood.
"These promising results show that a single blood test analyzing cell-free DNA can bring game-changing power to early cancer detection," said Dr. Kim. "We're deeply grateful to everyone who volunteered in Toronto. Many participants have described this study as lifesaving. The next step will be to follow the long-term outcomes."
Globally, the test detected a cancer signal in 216 participants with 133 confirmed diagnoses - a seven-fold increase in cancers detected, compared to standard screening recommendations from the U.S. Preventive Services Task Force. Of these cancers, 73 per cent were types without common screening options, and 53.5 per cent were caught at early stages (Stage 1-11).
Dr. Keith Stewart, Vice President, Cancer at UHN and Director of the Princess Margaret Cancer Centre, commended the team's leadership: "Our participation in PATHFINDER 2 reflects our strategic focus on early detection and finding more cures. This is a celebratory moment, and we're excited to continue advancing this critical area of research."
Results from the PATHFINDER 2 trial were released by GRAIL, Inc. on Oct. 17, 2025, at the European Society for Medical Oncology (ESMO) Congress 2025.
This story first appeared on UHN News