“Last week, President Joe Biden was seen for a new finding of a prostate nodule after experiencing increasing urinary symptoms,” his personal office said in a statement. “On Friday he was diagnosed with prostate cancer, characterized by a Gleason score of 9 (Grade Group 5) with metastasis to the bone.”

The aggressiveness of a cancer is based on several factors, including the tumor's grade and stage, and the cells' genetic fingerprint.