Dr Kwon on Imaging For Recurrence

This has unfortunately been posted several times before. I think Kwon had good intentions but ultimately does patients a disservice by not making clear that he is only expressing his opinions up until the very end, and presenting all these "gee whiz" cases without balance or explanation. I can only emphasize the importance of getting information from reliable sources (i.e., high level-of-evidence publications in peer-reviewed journals rather than random places on the internet and youtube videos).

Here's what I wrote last time a patient posted this:

• It was a presentation to patients, not doctors. He is obviously trying to give patients with metastatic disease hope. If he went further than the data allow, his heart is in the right place. As he stated at the end, he was offering his opinions, not facts.

• He showed a score of before and after PET scans, showing how radiation or surgery can result in excellent local control of detectable metastases. PSA disappeared along with the mets, as we would expect. Ironically, he started the presentation with half a dozen cases where patients died despite no detectable PSA, and said we have to be cautious about using PSA as the only tool to monitor progression.

• In all the cases but a couple, he offered 2-year PSA control as the outcome. Two years is not enough.

• Case studies are very useful for forming hypotheses. Pubmed is full of case studies of "miraculous" remissions. Kwon did not show the cases where it didn't work, except one. This is where science comes in - observations like his have to be tested in randomized clinical trials. "Gee-whiz" presentations are exciting, but what we want to know is if it really works, how much it works, and in whom it works.

Oddly, I have not seen any announcements of a such a randomized clinical trial from the Mayo Clinic. Last year, they began a non-randomized trial in castration resistant men, but that's all I've seen from them so far.

There is one at Johns Hopkins that uses their DCFPyL PET for early detection, and they expect to report some preliminary outcomes as early as next year. Unfortunately, it is a small study and not long-running enough to detect survival differences. Here is an article about it , if any are interested:

/pcnrv.blogspot.com/2017/07/first-us-randomized-clinical-trial-of.html

Other randomized clinical trials are ongoing in London and Montreal that will have larger sample sizes and are scheduled to run long enough to detect survival differences.

I would also ask you to read the following article, which cites what the actual evidence about this is:
/pcnrv.blogspot.com/2017/05/unwarranted-conclusions-about.html

Seems like the debate is about the value of hope. Most of the science we see is based on correlations, not causation. Certainly, we need good evidence before we propose a treatment. And there are those who lead the way with new treatments and some benefit. It is a fuzzy area, like most in the PC world. open-mindedness is the answer in my opinion. Denis

WOE-

I actually had lunch with Dr. Kwon (I use last names with no disrespect - I often refer to doctors as Epstein, Demanes, Zelefsky, etc.), and I very much like the guy, and I do think, as I said, that he has a good heart and is very well meaning. And by all accounts, he is a great doctor to work with. That doesn't mean that I have to agree with his approach in that Youtube video. I have heard many patients walk away from seeing that presentation at PCRI or watching that video thinking that what they saw was actual proof, and that metastasis-directed therapy is curable now. It's just not an opinion substantiated by any facts. And he only mentions that it's just his opinion fleetingly in the last couple of minutes - he doesn't provide that perspective from the outset. And, as I've said many times, if a patient defers systemic therapy because of it, it can lead to tragic consequences.

If he had shown some gee-whiz pictures and then gone on to announce that Mayo was going to start a randomized clinical trial (RCT) to see if there is any long-term benefit, I would have embraced it wholeheartedly. That's what hypotheses are for. But neither he nor Mayo have any such RCTs running. He is treating patients outside of such an RCT just based on his opinion.

I think doctors who speak to the public, if they wish to maintain any credibility at all, owe it to themselves and to patients to be the upholders of evidence-based medicine, and to very clearly distinguish when they are working outside of the box. (Snuffy Myers comes to mind as an example of a doctor who is known for being "out there," but he makes no pretensions to anything else). I believe that intellectual honesty has to be the starting point for any good doctor. That video was not intellectually honest. Watch it yourself and see if you walk away believing that he is just expressing a personal belief without any facts behind it.

I remember when he did a similar presentation at PCRI about cabozantinib, showing exactly the same kinds of select "gee whiz" pictures. As it later turned out, the drug was pretty useless. It's great that doctors like him are proposing hypotheses, but intellectual honesty and balance are required. It is misleading to show a select bunch of gee-whiz pictures and not explain that they demonstrate short-term local control, but do not prove any long-term benefit.

We all look at things , especially things like this , from our own perspective. I focused on the treatment of oligomets after primary treatment. And what I liked about it is that he was showing examples to illustrate his point of view that maybe in a post primary treatment BCR setting, we shouldn't be automatically radiating the prostate bed because only 30% of BCR is in that location. Now, did he cite any studies to validate the 30%? No, not that I recall. But I'll give him the rope on that one, based on his rep. Maybe there is a study that shows that to be a false statement. If so, I'm guessing we'll see it shortly In one of TA's posts. ;-).

Anyway, that's how I saw it, and why it resonated with me. I think the point made was a good one, there is at least as much, maybe more, overtreatment in the BCR setting as in the primary treatment setting. My biggest fear is recurring. My second biggest fear is having radiation to the prostate bed when the recurrence was elsewhere all along. I know others who feel that way as well.

So I want someone thinking outside the box.
I'm also (just) guessing, that if this presentation were to an audience of Drs., or researchers, he would have cited studies.

Pratoman,

Thanks for the post and the link.

Allen,
Thanks for your response and I very much respect that expanded explanation.I can see a little more clearly now. As for last night's reply, I was just having a frustrating day for me, aching all over, and trying not to blame the PCa. Anyway keep those Doctors honest and accountable whichever way you address them or call them out. Also more importantly, keep posting to inform us of the latest trail data and info about benefits of treatment and risks we crucially need that.
Thanks again
Dan.
P.S. to George,and sometimes fortunate patients like myself have seen over a 36 month delay in progression with Zytiga!

Allen, at about 13:45 of the video, Kwan cites cases of recurrence that was picked up by imaging, elsewhere, not in the prostate bed, with PSA of <.1 (which he refers to as "PSA of 0".) so there's that, Mayo must be doing something right in the imaging world.

Re the SWOG study, it refers to men with adverse pathology, yes? (I didn't read the link, I read your comments). What about if you average in all the men with good pathology, the low and low intermediate risk with no EPE, and no + margins? I'd be really curious to know what the % of recurrences for those men are limited to the prostate bed.

Is Kwon a liar? Is he misinformed? Is he pulling this stuff out of his @ss? Is this a veiled attempt to drum up business for his department at Mayo? None of this seems even remotely plausible.

Not trying to be argumentative. I Genuinely want to understand.

Pratoman asked about chance that recurrence is limited to prostate bd for low risk men.

Studies show that early SRT affords excellent cancer control for patients with BCR after surgery. And early here is 0.3 (not 0.03).

Prediction of Outcome Following Early Salvage Radiotherapy Among Patients with Biochemical Recurrence After Radical Prostatectomy

For example, a patient with pT2 stage, negative surgical margins, and Gleason score 6 at RP has a 9% BCR probability at 5 yr after eSRT if he is irradiated at a PSA of 0.3 ng/ml. This increases up to only 13% if eSRT is given at PSA 0.5 ng/ml. Conversely, a patient with pT3a disease, Gleason score 8–10, and positive surgical margins treated with eSRT at a PSA of 0.1 ng/ml has a 45% probability of BCR 5 yr after eSRT. This increases significantly to roughly 70% if the same patients receive eSRT at 0.5 ng/ml. Therefore, although the risk of BCR after eSRT increases linearly with increasing PSA even at lower PSA ranges, the optimal PSA trigger value for eSRT should be individualised according to the features of each patient.

Pratoman-

Separate "adverse pathology" into four parts- (1)positive surgical margins (2) high stage (e.g., pT3 and pT4), (3) high/persistent/rapidly rising PSA and (4) high Gleason score.

Positive surgical margins are a risk factor for recurrence, but it increases the probability of being cured by SRT. That's because it increases the probability that the cancer is still local.

Higher stage , PSA, and Gleason score are also risk factors for recurrence, and they increase the probability that cancer may have metastasized and become incurable.

You can see the relative magnitude and direction of those effects in the nomogram.

I tend to "distill" information.

I figure my chance of BCR at between 30% and 70%. (probably higher...but I factor optimism and hope into my calculations ) If my PSA continues to rise....those numbers get more "honed". (and not in my favor lol)

If PSA does continue to rise....and I choose SRT.....I figure a 20 percent cure (which I define as 10 years).

In TA's world....that's "statistically incorrect". In my world....it's common sense and instinct....based on what I've read and understood, read and not understood (which is the bulk of it)....and seen.

<<<< take your pick!

great thread!

(btw....i also figure....that if I wanted to *really* maximize my chance of cure....I would have already gotten SRT)


in other words.....one swing of the bat for cure. But I'll still live forever!

For what it's worth, I had a PSMA DCFPyL PET/CT scan at the NCI a week ago. I'm a little over four months post surgery. My current PSA is hovering at about .5 and my last pre-surgery PSA was 2.3 My pathology report was relatively good; G3+4, pT2c pNO PMn/a Group2, one small positive margin, and a low risk (.37) Decipher Score

What's not to be happy about? Well the post surgery PSA, and subsequent MRI and PET scan that reveled a (2.6cm) 1" tumor in my prostate cavity, but thankfully nothing anywhere else.

As of today, I'm planning on having my prostate bed radiated over 40 sessions with about 70 grays, total. I'm also hell bent on avoiding the ADT2 treatment my RO is pushing on me to possibly up his (my) positive outcome by a few points, at the cost of some sobering side effects.

Always searching out other options, I'm investigating salvage SBRT clinical trials at the U of VA and USC.

 
That early salvage pelvic radiation treatment is highly curative, there is no doubt.

Post Edited (garyi) : 11/26/2017 12:01:04 PM (GMT-7)

Gary said...
I'm investigating salvage SBRT

Hi Gary,

Here are a three studies which may provide helpful information:

CyberKnife stereotactic radiotherapy for isolated recurrence in the prostatic bed

ROBOTIC IMAGE-GUIDED STEREOTACTIC RADIOTHERAPY, FOR ISOLATED RECURRENT PRIMARY, LYMPH NODE OR METASTATIC PROSTATE CANCER

Salvage image-guided intensity modulated or stereotactic body reirradiation of local recurrence of prostate cancer

George

Post Edited (George_) : 11/26/2017 1:02:12 PM (GMT-7)