The announcement Sunday that former President Joe Biden was diagnosed with advanced prostate cancer has some people wondering how the disease could have been missed.

“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.”

Former President Biden's diagnosis has divided medical experts over the likely progression of his prostate cancer and resurfaced questions in Washington over his decision last year to run for reelection.