My impression (which might be completely wrong) is that PSA density might have been more widely used when prostate imaging was mostly by ultrasound, and didn't give much more information than size of prostate. Now that mpMRI scanning is used, the scanning process bypasses the usefulness of PSA density, since it leaps directly to imaging the prostate cancer resulting in a PIRADS score, which is more useful than the PSA level once you get that far through the diagnosis.
Normal prostate size is usually quoted at 30cc, but "normal" is something of a misnomer. Many men's prostates start growing again from age 25, and prostates up to 4 times this are also relatively normal in older men, so your 70cc is not particularly remarkable. If we scale your PSA of 318 back to a 30cc prostate, it would become 136, but you already know it's not all coming from the prostate.
Edited by member 29 Nov 2019 at 13:17
| Reason: Not specified