@peterj116 Yes, I agree 100% with everything you said. I am just curious about the sources of PSA beyond the prostate. Given that, as other folks have noted, there are other sources of PSA, even if what is produced is minuscule, why then even bother with measuring PSA out to three decimal places? I see no clinical value in such high precision data. I would expect a high potential for instrumental/lab error in such fine measurements as well.

Personally, I am quite happy and relived if my PSA remains below 0.1, as is my RO and urologist.