Pathologists grade prostate cancers with something called a Gleason score, based on how abnormal or healthy the cancer cells look under a microscope. The scores range from 6 to 10, with 6 being low-grade and slower-growing and 10 being the most aggressive. Biden’s cancer had a Gleason score of 9, his personal office said.

Doctors say aggressive prostate cancer, like the former US president's, can be treated but not cured. Here's everything you need to know about it. View on euronews