I found this interesting conversation on a doc/med-student blog, did not save the website, but can dig it out if anyone wants to take a look.
I had always wondered about the "% cores positive". Especially when there is a mix of grades, GG1 and GG2. Also, as Doc 2 mentions, the % of positive cores can bump you up into another risk category. I know, a little more goes into the decision making, buuuuutttt...
Would be great to hear any feedback or comments on this, or if anyone has seen any studies where they looked at this. Not sure if someone like Doc D'Amico broke it down to different GGs.
Doctor 1: I offer all my favorable intermediate risk patients AS. I steer most of the younger folks away from it do the small but non-zero risk of progression to Mets (1-10% depending on the series you look at) and very high rates of conversion to radical therapy (~50-60% at 5 years). I also get edgy with higher volumes of disease, even if it’s a 1-2 cores of GG2 in a background of 8/12 cores with GG1 (though that’s technically unfavorable IR per NCCN, which tbh I disagree with)
Incidentally I think this is the one area where focal therapy be beneficial. If you have low volume Gleason 7 disease and you can reduce their risk of progression to therapy from 60% to 20% with minimal ADRs that’s a potential benefit.
Doctor 2: I think NCCN is unclear on risk grouping based on volume of disease. There is no consideration of % cores positive for low risk. Someone can have 10/12 cores positive for GGG1 disease and anything, even AS, is ok. But now if the same person has a single core of GGG2 disease, they go all the way to unfavorable disease and need ADT if they opt for RT (and are no longer a Brachy only candidate)? Give me a break. I personally don’t count the GGG1 cores and neither do our urologists. It wouldn’t make sense.