Dr. Murphy on using race as a factor in developing prostate cancer guidelines

In this video, Adam Murphy, MD, MBA, MSCI, highlights his presentation, “Health Activism Lecture –Should Prostate Cancer Screening and Treatment Guidelines be the same for White and Black Men?” which he gave at the R. Frank jones Urological Society session during the 2023 American Urological Association Annual Meeting in Chicago, Illinois. Murphy is an assistant professor of urology at Northwestern University in Chicago.

Video Transcript:

The one thing that I think is really important is that they probably should not be the same guidelines. The problem is that you need level 1 evidence to determine what the actual guidelines probably should be. I'm going to make an argument today that most of our biomarkers that we have out for prostate cancer risk profiling are not calibrated to the risk profile of Blacks. I don't think it's calibrated to the risk of Asians either. The reason that is, is that if you have a group that's at high risk of cancer, and bad cancer, the positive predictive value goes up when you have a high prevalence population. So, when you're predicting a bad outcome, and it's more common, what the score says is not going to be accurate, oftentimes, in another racial group. If there are differences in the populations – it's not even different – there'll be differences in the same calculator in different populations in the US, even if it were all Whites, or all Hispanics, or all Asians, because if it's a tertiary care center, they're going to be skewed towards getting the more aggressive cancers. So, the prevalence will go up in those populations.

Because we don't have calibration data on Black, or Hispanic, or Asian men in many of these risk tools, we don't know the impact of these tools as screening tests. If you come in for the same PSA between a Black and White person, for example, the PSA is going to have a higher positive predictive value in Blacks for every PSA level. That means that if you pick a threshold, you're going to miss more cancers on one side, just because you picked the threshold. Now you go into the secondary screening tests, like an MRI, 4Kscore, prostate health index, ExosomeDX test. If they don't have the calibration data, we don't know the right threshold to use in those populations.

You can get away with that if you put it in a risk calculator. But even that risk calculator has to be calibrated for the race that you're talking about. So, right now, I can't tell you for sure whether the screening guidelines are right or wrong, or what the risks and benefits are of using them, and how it compares to the general population in Blacks or Asians because no one's ever given me that data to say this is well calibrated or not. I think that we need guidelines that include an accurate assessment of the impacts of the risks and benefits of these decisions. And because it's been done in the general population, you could start with looking at what the risks and benefits are in the White population for over-detection, over-treatment, mortality benefit, and then see how that applies in other populations when you use those same thresholds. Then you could, through modeling or through clinical trials, see if you can get better or approach that same level of risk/benefit ratio in the other racial groups.

This transcription has been edited for clarity.