“Liquid biopsy” is a form of cancer screening that detects biomarkers in the blood with a simple draw. Research indicates that it could help to detect disease months or even years before other, more expensive and more invasive forms of screening, helping to save lives. So how exactly does it work? Is it better at detecting some cancers compared to others? And how can it help oncologists treat already diagnosed cases? Medcan’s director of clinical innovation, Allison Hazell, investigates with the help of Dr. Lewis Roberts (pictured above), director of the Mayo Clinic’s Hepatobiliary Cancer Lab.