PORTOS

[Jmr11820]

I’m beginning week 3 of IMRT after a small uptick in my PSA from .01 to .03. Things are going well but in my head I am bugged by the fact that I had a low PORTOS score associated with my DECIPHER GRID. Neither my urologist nor either of the two RO’s I spoke with before treatment seemed very interested in discussing PORTOS. Has anyone received any advice from their doctor regarding the PORTOS score and how much consideration to give it in treatment plans?

[Tall_Allen]

It is really not prospectively validated - just an interesting idea at this point:

pcnrv.blogspot.com/2016/11/...

[Jmr11820 in reply to Tall_Allen]

Thank you Allen, I did read that piece. To me it actually gives PORTOS some merit but with several caveats. I appreciate you response.

[Tall_Allen in reply to Jmr11820]

I've become very careful about these retrospective genomic studies since Oncotype Dx failed to predict active surveillance progression prospectively.

[Jmr11820 in reply to Tall_Allen]

I didn’t know about that. Genomic business is quite the big business isn’t it? Thanks again.

[Blackpatch]

Hello Jmr11820

I have read several of your previous posts - we have somewhat similar histories, and are both "cursed" with a high Decipher reading - mine is 0.91, so right up there - yay!

I read my GRID results very carefully and then dug out all the underlying source papers, and followed up for later publications by those authors and others working in the areas concerned - a very exhausting task that took months.

Years ago, I was involved in applying an infrared spectroscopic technique, FTIR, to a wide range of samples drawn from across the operations of a minerals and steel company, and we were very excited to find that if we measured the spectra of hundreds of "training " samples, we could often use sophisticated mathematical techniques to predict the physical properties of unknown (but quite similar) test samples by measuring their FTIR spectra and applying the spectral transformations we had derived from the training set. It was pretty exciting stuff, we took out a few patents and published quite a few papers. In the world of mineral production and processing, where thousands of very similar samples are regularly analysed, this was a significant development.

To my mind, Decipher is trying to do something fairly similar - but without the advantage of the hundreds of "training samples", and with their "unknown specimens" having all sorts of confounding complications, such as diverse treatment histories etc - prostate cancer patients are a good deal more complicated than samples of iron ore or coal!!

So what?

I found my very, very high Decipher quite frightening, and it caused me to act quickly, having eSRT when my recurrent PSA reached 0.12 - you are well ahead of me there, by the way!! It also contributed to my decision to undertake a year of ADT, including 8 months (all I could stand) of Zytiga.

Where I have landed is that Decipher is useful for providing directional information but you can't push it too far. As TA has said, the Decipher correlations fall well short of clinical testing standards. And from conversations I've had with a number of researchers working with the data, it's likely to stay that way - there just isn't the money or the patient numbers to support trials of this technology, and the genetic testing techniques themselves are evolving too quickly for labs to want to lock into them for the years involved in clinical trials.

Despite my very high Decipher, and being in the highest 1 -2% for a couple of very nasty proliferation genes (not unrelated events, I'm sure), I was one of the lucky 1 in 4 with a high PORTOS - very high in fact! So I decided I had done all I could about the high Decipher, and would focus more on the PORTOS - which means that if I think about Decipher these days, it's PORTOS that I think about. I don't mean this to be taken lightly - but I have read so many Decipher papers that have shown men with very high/low results turning up precisely where their Decipher wouldn't have predicted them to be... so I have decided that at this stage of development, genetic testing of PCa can't be treated as highly deterministic. If it helps you make a decision, great - but don't let it beat you up... chances are you'll live long enough to prove it wrong!!

I do wish you all the very best, and look fwd to hearing how things turn out for you....

Stuart

[Jmr11820 in reply to Blackpatch]

Thank you very much for your thoughtful and detailed response. I’ve noticed that many doctors seem to put much more merit in DECIPHER low scores than high scores. That’s just a casual observation. I’m curious, what did your RO say about your PORTOS score as you were planning your treatment, and was you radiation response reflective of your score? Take care, best wishes.

[Blackpatch in reply to Jmr11820]

Hi Jmr11820

My RO was pretty hesitant about eSRT given the pT3b; in his view, once it’s in the SV, cure is pretty hard to achieve. However, the SPPORT RTOG 0534 early interim results reported in early 2019 got him over the line on trying prostate bed plus lymph nodes plus ADT. We have subsequently been looking into getting Decipher more widely available in Australia, but the technology (the actual measurement technique) is pretty old school, so we have been unable to make this happen.

Stuart

[j-o-h-n]

Since I forgot what Portos meant, I posted the meaning for me and for others:

PORTOS: a gene signature that predicts salvage radiation success

Posted on November 2, 2016 by Sitemaster

3 Votes

Salvage radiation is curative in roughly half of all cases. There are many factors that contribute to an unfavorable prognosis, including waiting too long, high PSA and rapid PSA doubling time, adverse post-surgery pathology (stage, Gleason score, positive margins), and high Decipher or CAPRA-S scores. But, other than a detected distant metastasis, none can predict failure of salvage therapy.

For the first time, there now seems to be a genetic signature that predicts when adjuvant or salvage radiation (A/SRT) will succeed.

Good Luck, Good Health and Good Humor.

j-o-h-n Thursday 05/28/2020 5:57 PM DST

[Jmr11820]

Thanks John. As the proud owner of a low PORTOS score, my hope was you’d cite a study saying that PORTOS was BS. 😊

Honestly, I appreciate your reply. Take care