Says RP Better than RT - What to Make of It

[ADTMan]

renalandurologynews.com/rep...

[Tall_Allen]

Another useless database retrospective study.

[ADTMan in reply to Tall_Allen]

I suspected as much. Unfortunately, many men will make their decision because of it. Which raises another important question.

[Tall_Allen in reply to ADTMan]

Yes, patients who do their own research often fall into the "levels of evidence" trap.

[maley2711 in reply to Tall_Allen]

Are there useful retrospective studies? And, why would the EAU allow such a useless study to be presented? If there are useful retrospective studies , what distinguishes them?

[Tall_Allen in reply to maley2711]

Retrospective studies are hypothesis generating and are useful to other researchers but not to patients. Some are better than others, and levels of evidence and GRADE are a big subject. If you are interested, follow the links here:

prostatecancer.news/2022/07...

[maley2711 in reply to Tall_Allen]

OK. I read that and have no/little argument with your summary! However, I've read many of your great blog articles, and haven't you used retrospective studies of this or that type of treatment as somewhat the bases for your conclusions? Is it impossible that a retrospective database study might actually make someone take a 2nd look at conclusions from a randomized study with a limited n??

A number of database studies I've seen mention an effort to do some type of one to one "matching" of a certain subset of the large N the database provides. Is that matching of no value at all?

BTW, saw something interesting the other day re the spread of BCR probability numbers between GG1 and GG5. True or not, the claim was, referring to some study of such numbers, that the spread is much wider with surgery than with RT? Seen anything like that? Make sense?

[Tall_Allen in reply to maley2711]

They are hypothesis-generating. They are subject to a huge source of error called selection bias. It's been proven that propensity-score matching can provide any answer the researcher wants:

onlinelibrary.wiley.com/doi...

Some retrospective studies are higher level evidence than others, but none are LEVEL 1, which must be prospective. If level 1 is impossible, teams of researchers go through the available studies in fine detail to arrive at provisional conclusions.

[EvFC in reply to Tall_Allen]

Some of the brachytherapy boost studies are retrospective. Does this make them less valuable in terms of assessing the outcomes of different treatment types?

[Tall_Allen in reply to EvFC]

Yes. Ideally we will have prospective studies. The Kishan study was at centers of excellence, so at least we know that all patients got excellent treatment. What we don't want to rely on are database analyses.

[EvFC in reply to Tall_Allen]

I am not sure I understand. I did read the article you wrote. I understand how selection bias can impact the value of a study and why double blind randomized studies are the gold standard. I don’t understand what makes this study not worth considering, yet other retrospective studies worth considering? It’s confusing to me. We’re trying to evaluate brachytherapy boost as an option, but it’s hard because there are no prospective studies that evaluate it against surgery. So how can you truly compare the two?

[Tall_Allen in reply to EvFC]

The Kishan study is the best we've got so far.

prostatecancer.news/2018/03...

What it tells us is that very high-risk patients receiving BBT at the best hospitals did significantly better (subsequent metastatic detection within 10 years was 4 times worse after surgery!) than those very high-risk patients who had prostatectomies at the top hospitals.

However, it was not a randomized clinical trial (RCT), which is the only way we can know for sure. There is an ongoing Scandinavian RCT, but results are many years away. Until then, it is the best info we have.

[Justfor_ in reply to EvFC]

Quoting from another thread: "Ignore the idiocy you see posted on social media". The relative success rates obtained at the "best hospitals", disseminated via peer reviewed journals will become the new norm in your city's hospital. Magic no?

[quietcorner in reply to Tall_Allen]

TA, there are some useful, aka informative, retrospective studies that bring to light a hypothesis which leads to prospective studies. Sometimes we can be waiting decades, as in the Framingham Study, to confirm the same info we may have gleaned from a retrospective study.My question: how does one determine which retrospective studies one should pay particular attention to?

[Tall_Allen in reply to quietcorner]

Retrospective studies are hypothesis generating and are useful to other researchers but not to patients. Some are better than others, and "levels of evidence" and GRADE are a big subject. If you are interested, follow the links here:

prostatecancer.news/2022/07...

[Don_1213]

It's a journal for urologists.. enough said? "how about radiation..?" "well, look right here at this study from last week.."

[maley2711 in reply to Don_1213]

what study?

[Don_1213 in reply to maley2711]

Uhhhh... the one we're discussing?

[maley2711 in reply to Don_1213]

Ok, I get it.....the urologist showing this study, in order to bolster the argument for RP. I thought you were saying you have a study showing same or better efficacy for IMRT......

[RCOG2000]

all "radiation" treatment is not alike this study only looked at EBRT radiotherapy hads advanced remarkably over the twenty four years that i have been a patient. brachy boost was not a part of this study all surgeons and surgincal procedures are not the same either.

[fast_eddie]

Surgeons are always going to recommend surgery. Anyone surprised by that?

[Tony666]

the other thing is that many surgery patients go on to have radiation if there is recurrence. So they are not really “surgery only”. And the side effects of radiation after surgery may be worse than radiation without surgery.