@handera : responding to your questions:
I had an elevated and fluctuating PSA for a number of years and was under the care of a center of excellence which included multiple MRI's and biopsies over 15 - 20 years, all of which were negative. I began to see a local urologist in 2023 and during my first visit we reviewed all of my previous history and the urologist did a DRE and a PSA. The DRE was normal - no abnormalities detected and the PSA was stable from the prior reading (basically unchanged for the prior year). At the end of that first appointment I asked about the newer genomic tests I had been reading about on this forum and others and asked if I could have one of those tests prescribed. I was given the ExoDx urine test and it showed a 36% probability of "treatable" prostate cancer. An MRI was done which was completely clear - no lesions or suspicious areas seen. The urologist recommended a saturation biopsy (24 cores) and that showed 2 of the 24 cores with a small amount (5% in each of the cores) of Gleason 4+5 cancer. Due to the high Gleason score, I decided to have an RALP and following that procedure the pathology report on the full prostate examined after removal resulted in the Gleason score being downgraded to 4+3 with tertiary 5. I had no further treatments and have my PSA checks every 3 months have all been < 0.1 (considered undetectable). I did not get a Decipher score.

My case is a bit unusual in that all indications other than the ExoDx seemed to indicate no cancer (normal DRE, stable PSA, MRI was clear) yet the saturation biopsy showed cancer. If your friend has an elevated ExoDx value, I would suggest proceeding with the MRI and on to a saturation biopsy regardless of what the MRI shows (but the MRI has value in case a lesion is seen as then that lesion can specifically be sampled using the Fusion biopsy process.)

Needless to say, my experience has made me a huge proponent of the genomic tests like ExoDx or PSE. My cancer would not have been detected as quickly as it was if I had not had the ExoDx test. Those tests are relatively inexpensive, and I think they should be used as a standard screening tool just as the PSA test is.