What you can’t prove can still be presented as if it were the truth


Another new article (this time in the journal JAMA Surgery) has tried to draw links between the USPSTF guidance on prostate cancer screening and a decrease in the numbers of men being referred to urologists for prostate biopsies and radical prostatectomies.

This new article by Halpern et al. is a little disturbing, because the simplistic “meaning” of the study, as stated in the “Keypoints” section of the article, reads as follows:

These findings represent the downstream effects of the US Preventative Services Task Force recommendation.

This doesn’t seem to correspond at all with the more complex conclusion presented in the “Conclusions” section of the study’s abstract, which reads

Following the 2012 USPSTF recommendation, prostate biopsy and RP volumes decreased significantly. A panoramic vantage point is needed to evaluate the long-term consequences of the 2012 USPSTF recommendation.

In the full conclusion at the end of the article, the authors manage to include both of these highly contradictory pieces of information and infer that they are actually mutually supportive. This sort of documentation seems to be based on the principle that if you say something loudly enough and often enough it is necessarily true. That is not a perspective we subscribe to.

As the authors themselves acknowledge in the full text of their article, there are a number of reasons why there might have been a significant decrease after 2012  in (a) the numbers of patients receiving prostate biopsies and (b) the numbers of patients being given radical prostatectomies as first-line treatment for prostate cancer. While The “New” Prostate Cancer InfoLink is fully appreciative of the fact that the widespread use of the PSA test may have declined significantly between 2012 and 2016, what the authors claim is that the following data are a direct consequence of the USPSTF recommendation:

  • A decrease in the overall average (median) biopsy volume per urologist from 29 per year (in 2009 to 2012 ) to 21 per year in (2013 to 2016), i.e., a decrease of 28 percent
  • After adjusting for physician and practice characteristics, a decrease in the median biopsy volume per urologist of 29 percent
  • A decrease in the overall average (median) volume of radical prostatectomies per urologist from 7 per year (in 2009 to 2012) to 6 per year (in 2012 to 2016), i.e., a decrease of 14 percent
  • After adjusting for physician and practice characteristics, a decrease in the average (median) volume of radical prostatectomies per urologist of 16 percent

One could just as easily make the case that these declines are a direct consequence of changes in guidelines issued by the American Urological Association and the National Comprehensive Cancer Network, both of which now recommend a less aggressive use of biopsies and a less aggressive use of radical prostatectomies and other forms of invasive first-line treatment — particularly among the high numbers of men initially diagnosed with low-risk disease. However, we aren’t going to draw that conclusion either … because (again) there are no data to support that conclusion.

We wish to be very clear that we are not (by any manner of means) suggesting or implying that we agree today (or that we agreed at the time) with the 2012 USPSTF guidance on use of the PSA test to screen for prostate cancer. However, we also don’t think that that this reported decrease in the average numbers of prostate biopsies and the average numbers of radical prostatectomies can necessarily be laid at the door of the USPSTF.

There are at least two core reasons for considering our perspective:

  • Over the past 7 years there has been an increasing tendency for large numbers of radical prostatectomies to be carried out at high volume, specialized prostate cancer treatment centers. This would inevitably lead to a decrease in the numbers of radical prostatectomies being carried out by general urologists as opposed to prostate cancer specialists — and frankly we see this as a good thing. If a radical prostatectomy is going to be done, it is a complex operation best done by surgeons who specialize in the conduct of this operation.
  • New tests like the Prostate Health Index or phi test, the 4KScore test, multiparametric MRI scans, and others, can now be used to get a better “read” on whether (or when) a man with a slightly elevated PSA level really needs a biopsy at all. This would inevitably lead to the need for fewer biopsies. And in any case, there is an analogous argument that high quality prostate biopsies are best done by people who do hundreds of these procedures a year (as opposed to general urologists who do as few as 20 to 30 a year).

A commentary on this article on the Mescape web site is headed “Big drop in prostate biopsies, prostatectomies in US”, and could easily foster the idea that a significant drop in the numbers of biopsies and radical prostatectomies over the 7-year-long time frame from 2009 to 2016 is necessarily a bad thing. In fact, however, it may well be a good thing, and simply reflect some real progress in the battle against unnecessary over-treatment of low-risk and indolent forms of prostate cancer. We are going to need data over a much longer time span to really be able to understand what is going on here.

The recommendation of the USPSTF in 2012 is certainly relevant … but it may well not be “the big dog in the room”.

 

One Response

  1. While I am against the Grade D recommendation by the USPSTF, I said 4 years ago when the recommendation was finalized that if there is a good thing that will come out of this it would be a new focus on how to detect and monitor early stage cancer. And I think that a lot of good did happen as a result of research and the USPSTF recommendation.

    I have a unique view inside the AUA and the way it has changed over the last few years. This is mostly a good development and not a bad one. Will it be enough for the USPSTF to change the Grade D? If anything they may just take the easy road and make the recommendation an “I” — basically indicating that the data on a PSA test for screening is inconclusive on the harms versus benefits.

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