Ian Sample speaks to the Guardian’s health editor, Andrew Gregory, about the worrying global rise in cancers in under-50s, and hears from Yin Cao, an associate professor in surgery and medicine at Washington University in St Louis, who is part of a team conducting a huge study into why young people are developing bowel cancer at record rates. Help support our independent journalism at <a href="https://www.theguardian.com/sciencepod">theguardian.com/sciencepod</a>