RP vs radiation. Survival from time of metastasis.

[pjoshea13]

Presented at the American Urological Association 2020 Virtual Experience. [1]

"... men who received radiation alone had 77% higher overall mortality after developing metastatic disease ... compared with men who underwent RP."

"... the results add to a growing body of evidence that support the benefit of extirpation of the primary disease on OS after developing metastatic disease ..."

"One theory for the finding is that early use of ADT as well as RT may potentiate epithelial-mesenchymal transition, which mediates tumor invasion, metastasis, and development of castration-resistant tumors, leading to a worse outcome ..."

-Patrick

[1] urologytimes.com/aua-annual...

[Cmdrdata]

I think this article is not conclusive and correct. The paragraph indicating the number of patients studied (664) is confusing and perhaps mistaken. Initially they use RT vs RP to differentiate the group and in that one paragraph, they refer to “PR”. Is that a mistake meaning they were referring to RP or RT group? It is my understanding that when Gleason score is over 7, the preferred treatment is radiation, because of potential that the beast is already elsewhere but still undetectable.

[Dachshundlove]

There is always the risk of patient selection bias fouling data too, when comparing RT to RP. Many surgeons will not perform RPs if the RPs intent is not curative.

Just a thought.

[cesces]

I seem to remember someone posting a study that said there was no difference.

That's a big difference in results.

It's hard to know which to rely on.

[Fairwind]

These study groups tend to get the results they pay for...Lots of moving parts to account for..

[noahware]

"Notwithstanding the inherent selection bias at the time of choosing the type of local treatment because of unmeasured confounding variables..."

That seems like a pretty big deal to me. It's not like a coin toss. Or is it? Well, not if you are a surgeon (heads, you win, RP is the best way to go) or an RO (tails, you win, RT is the best way to go). Seems like there are all kinds of reasons, both good and bad, to pick one over the other.

"The cohort consisted of 664 patients who... had progressed to metastatic disease between 2010 and 2018. The focus here is to see what would happen after metastasis. Median follow-up from the date of metastasis was 30 months for the RP group and 29.4 months for the radiation group."

I'm confused. How do you establish a "date of metastasis" for a man with PC? You can only establish the date that metastasis is identified clinically via scans. So couldn't there be a difference for the RT group and the RP group in how that date gets established?

The follow-up cannot likely be from an actual "date of metastasis" that has been determined in a biological sense. It can only be determined in a clinical sense, and it seems very possible that these two groups of men experience differences in clinical approaches that cannot really be adjusted for.

For example, the group treated with radiation was more likely to receive ADT before metastasis compared with the RP group (76% vs 61%)... but why? Maybe because they still had prostates and so had higher PSA as a group. Or maybe because certain clinicians (Uro's, MOs, ROs) have slightly different approaches to RP patients compared to RO patients?

When I was diagnosed with Gleason 3+4 my PSA was 20, so I had scans, and they revealed mets. Now suppose my PSA was about half that, a few years back, and I got a biopsy and then an RP. No scans needed with a PSA low enough. But might I still have mets? Of course. Officially, though, my "date of metastasis" would still be off in the future somewhere.

Imagine... if I had my prostate removed a few years ago I could still have mets in my spine similar to the ones I have now, but I would have no idea they were there. Not only would I be labelled as having non-metastatic cancer (in spite of having mets), I could be labelled as having been "cured!"

[Gearhead]

I don't see this addressed very often, but it seems to me that age should be a significant factor affecting the RP choice for men with metastasized PCa.

[Hidden]

I was told by two urologists that I was not a good candidate for RP after having had TURP surgery 10 years prior to diagnosis. I didn't have to fret over the RP vs RT choice. I actually had neither -- I went for HIFU.

[Don_1213]

"At the time of metastasis, patients in the RP group were younger (63.8 ± 7.25 vs 69.3 ± 7.67 years; P <.0001), had a lower prostate-specific antigen (PSA) level at prostate cancer diagnosis (7.8 vs 10.9 ng/mL; P <.0001), and were more likely to have a Gleason score greater than or equal to 8 (64.5% vs 54.5%; P = .0089). The men in the PR group also had lower PSA levels at the time of metastasis compared with those in the radiation group (6.4 vs 17.2 ng/mL; P <.0001). The group treated with radiation was more likely to receive androgen-deprivation therapy (ADT) before metastasis compared with the RP group (76% vs 60.7%; P <.0001)."

Sounds like apples to oranges to me. Seems an invalid study given the differences between the groups. And this was a retrospective study with data pulled from some cancer database, which are pretty much notorious for missing data.

"On multivariable analysis, men who received radiation alone had 77% higher overall mortality after developing metastatic disease (P = .0013) compared with men who underwent RP.On multivariable analysis, men who received radiation alone had 77% higher overall mortality after developing metastatic disease (P = .0013) compared with men who underwent RP."

Well - 6 years age difference might account for the difference in overall mortality. Not only due to age related deaths, but also due to comorbidities that take men out. We also have no idea of what the radiation treatments were - since they don't seem to be noted in the study. They could be techniques that have been obsolete for the past 10+ years. And the information ADT seems to be "some men took it, some men didn't and some we don't know."

My urologist was the one who taught me how to look at studies. He really hates the retrospective ones since drawing from an old database of information allows a real selection bias to happen - intentionally or unintentionally.

This was a poster talk - and having done these sort of conferences in my former life as a physicist - poster talks are never given the weight that a real talk with a written and reviewed and published paper are.

My overall view.. meh.