Yesterday’s post described research performed at Northwestern University that found a sharp increase in the number of men diagnosed with advanced aggressive prostate cancer between 2004 and 2013. The research interpretation raised the possibility that the United States Preventive Task Force (USPTF) decision to recommend against the use of the PSA test for prostate cancer screening was to blame for this high increase of aggressive disease.
A number of news media pick up the story as well as this blog.
Additional scientific commentary has questioned the research techniques used to draw this conclusion. According the American Cancer Society the study conclusions do not pass statistical muster and the increases in advanced prostate cancer may not be statistically meaningful!
The concern about the statistical methodology centers on the use of absolute numbers, as used by the researchers at Northwestern University as opposed to the population rates (numbers of cases per a certain number of people).
This statistical flaw is significant and limits any real conclusions that can accurately be drawn from this specific study. Raw numbers do not take into consideration many alternative explanations for the increase. Items like our aging population or our increased scanning sensitivity as opposed to the lack of screening could explain the higher raw numbers found in the original study.
From a simple scientific stand point we do need to acknowledge the significant flaws in the conclusions reached in yesterday’s blog post, however it also does not mean that our failure to adequately screen men is, in fact, the main driver of the increasing numbers of men diagnosed with aggressive, advanced prostate cancer.