Canadian researchers launch major trial of liquid biopsies for cancer follow-up

Canadian researchers at University Health Network in Toronto are launching a fiveyear clinical trial to study whether liquid biopsies can improve followup care for cancer survivors. The study will enroll more than 7,000 patients who have already completed standard treatment for different cancers. Researchers will use blood tests to look for tiny traces of tumour DNA that could signal a cancer may return before it appears on scans or routine exams. Doctors involved in the project say the goal is twofold: to find recurrence earlier so patients can receive treatment sooner, and to identify cases where further aggressive treatment may not be needed if no residual disease is detected. The trial, known as SHERLOCK, is expected to run until 2031. Experts caution that the technology is still in its early stages. Liquid biopsies can produce false positives and false negatives, and questions remain about how often the tests should be repeated, how they should be used in routine care, and who should pay for them. Researchers say the results could help determine whether the tests should become a standard part of cancer followup in Canada.