The announcement that the former president has an "aggressive form" of prostate cancer sparked many questions about the disease. Here's what to know.

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