Suggest he has a biopsy.
My PSA was only 2.81 then flared to 5.61 after a routine blood test.
I immediately had a biopsy that showed a Gleason score of 8 and advanced prostate cancer. I opted to receive 28 Proton radiation treatments. I also received a 3 month Lupron injection Prior to my radiation treatment and a 3 month injection post radiation treatment.
Although, perhaps necessary (?), My after effects of Lupron are horrible. I wish now I would’ve had my prostate surgically removed.
(I am the same age as your grandfather.)