A randomised placebo-controlled phase III trial of the effect of the omega-3 fatty acid eicosapentaenoic acid (EPA) on colorectal cancer recurrence and survival after surgery for resectable liver metastases (The EMT2 study)

Every day, 447 patients with colorectal cancer that has spread to the liver will be given either high-dose fish oil capsules or a placebo before and after surgery to remove their tumours, in a trial testing whether the omega-3 fatty acid EPA can stop the cancer coming back. Colorectal cancer that has reached the liver is often treated with surgery, but the cancer returns in many patients. There is no widely accepted, low-toxicity drug to reduce that risk. EPA, a natural omega-3 fatty acid, has shown anti-cancer effects in laboratory and early clinical studies, but no large trial has yet proven it improves survival. If EPA reduces the chance of recurrence by 30% or more, as the trial is designed to detect, it could become a simple, cheap, and well-tolerated addition to standard post-surgery care. Patients would take daily capsules for at least two years, with no need for chemotherapy-like side effects. The trial also measures quality of life and cost-effectiveness, so if successful, the NHS could adopt EPA therapy as routine practice for this patient group.