Hoo boy. Ok. I'm going to share this one, but with a bit of trepidation. This will be a little long.
Let me start with some caveats about
the study: it's retrospective, so has inherent selection biases and so on. It's from 2011, so necessarily based on work done up to 10 years before that; hence it's going back a long ways in the universe of radiotherapy. The minimum radiation dose was 75 Gy, so not sure what the actual distribution was beyond that. We're almost universally today using at least 79.2 Gy. Brachy boost was not included in this study as far as I can tell. The dose escalation today gives superior results to what used to be possible. And finally, the title is alarming, with Words We Don't Use.
I read this abstract, and had to get the full article from my U of Mich Cancer Center patient information center. (They're very helpful). This is a long paper, and I have read it several times. Tall Allen was able to reinterpret studies like this, and explain them in easier to understand language. I won't try to do that, for risk of misleading anyone. But I do have just a few observations.
Is that enough foundation? I hope so.
I'm sharing this for really only one reason. I have long chafed at the idea of the equivalence in defining "high risk" as PSA>20, or stage cT3 or T4, or Gleason 8-10. The metastatic capability of those wonky Type 5 cells seems so much out of character to the risks from the other parameters that I've never been comfortable with calling those all the same. The G9/10 (or rare G8 with Type 5, or maybe even G7 with tertiary 5) are so uncommon that they always get lumped in enough others to, in my mind, blur the results. The "G8-10" in as study is likely to be 80% or more G8, so the G9/10 gets lost in there.
This study definitely reveals a significant distinction caused by the Type 5 cells. So much so, that it implies treatment decisions should be made differently due to their presence. This study even suggests that Type 5 cases may benefit from immediate and permanent HT upon diagnosis (oh my...). It also supports more recent studies suggesting a course of docetaxel chemo after radiation therapy. Finally, they also suggest that the probability of systemic spread is so high, that local dose escalation (brachytherapy) is not as likely to be helpful as with others, and that enhanced systemic treatments should be strongly considered (again, chemo, advanced HT options, etc.).
So when they suggest to a G9/10 person that 18 months of HT has been shown to be fine, that's been based on the traditional "high risk" definition. No study I've ever seen has enough G9/10 cases to draw a conclusion like that, for G9/10 cases
. It's always lumped in with the G8 and other categories so the researchers can draw conclusions justifying the money spent on the study.
Ok, so here's the link to the study, with the actual title of the study. Please don't freak out about
it. With modern treatment options, I don't think things are as clear cut as this study shows. And as I've said before, don't quit buying green bananas. Treat the heck out of this version of PCa, don't shy away from aggressive options, but also don't sit around fussing about
it. Life is precious, and maybe things like this help us have a better perspective on just how precious it is.Gleason Pattern 5 Is the Greatest Risk Factor for Clinical Failure and Death From Prostate Cancer After Dose-Escalated Radiation Therapy and Hormonal Ablation
If there's interest, I'll post a couple of the clearest Kaplan-Meier curves showing the effect of the Type 5 cells. I think that would be ok without violating copyrights. If you've read this far, I'd suggest obtaining a copy of this paper yourself (the actual paper's content is far more dramatic than what they show in the abstract). I have never seen a clearer study regarding this issue.
Since this is now what's being called Gleason Grade Group 5, I'm hoping that in the near future we'll see more studies segregating those results for treatment options and so on.