Why are so many young people getting cancer?

Scientists don’t know yet, but diet, gut bacteria and microplastics could play a role

An illustration of a young adult in silhouette profiled against a brightly colored microscopic image of cancer tissue

Since the 1990s, rates of early onset cancer, diagnosed before the age of 50, have been rapidly increasing around the world.

Tim Robberts/Stone/Getty Images plus; Sidi A. Bencherif, Thomas Ferrante/Wyss Institute at Harvard Univ.; adapted by T. Tibbitts

Ryan Decembrino knew something was seriously wrong.