That is a very interesting question Adrian.
I think Dr Scholz’ view of Gleason score (and also Cribriform) is that it is purely a diagnostic indicator of the risk that a prostate cancer is likely to spread. It is a fairly crude indicator but for a long time it has been the best we had.
The more confident you are that the cancer has not spread (e.g. from PSMA PET scans and post-treatment ultrasensitive PSA levels) the less important Gleason score becomes. Dr Scholz’ view is that PSMA PET scans have already reduced the importance of Gleason as compared with periods in the past.
Of course we can never have certainty. There is always a small chance that some tiny amount of cancer is lurking somewhere and then becomes active at some point (e.g. if our immune system becomes weakened). The risk of that is still to some extent linked to Gleason score, even several years after treatment. But it doesn’t alter the fact that having an undetectable PSA is a very good place to be regardless of Gleason score.
For example, you might be interested in this research which gives an indication of the relative importance. At 5 years after prostatectomy the hazard ratio (relative risk of future recurrence) for Gleason 8+ was about 2 to 1 whereas the hazard ratio for PSA <0.02 was about 37 to 1, and 98.5% of men with PSA<0.02 at 5 years remained recurrence free at 10 years.
https://pubmed.ncbi.nlm.nih.gov/39716720/
Kevin