Why is cancer on the rise in younger people?

The number of people under 50 being diagnosed with cancer has risen dramatically in recent decades. Many cases cannot be explained by a family history of disease or any lifestyle factors—such as smoking, drinking or unhealthy foods—that would otherwise put the individuals at a higher risk. Explaining this rise in early-onset cancer has therefore presented a conundrum. But clues are now emerging—is there some kind of exposure in the environment that could perhaps explain some of the cases?

Host: Alok Jha, The Economist’s science and technology editor. Contributors: Ann Young, who was diagnosed with breast cancer in her 30s; Mike Stratton of the Wellcome Sanger Institute; Slavea Chankova, The Economist’s health-care correspondent. Thanks also to Meg Bernhard, who wrote about Ann’s story in The Economist.