They found those with multiple copies of a particular gene did not respond to abiraterone and enzalutamide - drugs commonly used to treat advanced cases. More trials are needed but the team hope the test could prevent thousands of men undergoing unnecessary treatment and allow more personalised care. The drugs abiraterone and enzalutamide are given to men whose cancer is no longer responding to traditional hormone therapy and has started to spread. Costing less than £50, the test is a quick and relatively cheap way of preventing men from undergoing the side effects of therapy that will fail.