In the May 27th issue of the NEJM, a study was released that concluded that biopsy-detected prostate cancer was not rare among men with PSA levels of 4 or less. Prostate cancer was diagnosed in 15 percent of cases in the group with PSAs of less than 4, and of those cases, 15 percent were high grade.
This begs the question – should the threshold for biopsy be lowered? The accompanying editorial opines not and gives several reasons. The most compelling is that there is no convincing evidence that men who are treated when their cancers are detected at PSA levels below 4 have better outcomes than men who are treated when their PSA is higher than 4. In fact, there is no proof that PSA screening even saves lives.
Again, this brings us to the disconnect between EBM and the real world. You can bet that this study will increase the number of prostate biopsies, despite the absence of PSA mortality evidence. In light of this study, it probably would be easier to err on the side of the biopsy than to risk relying on EBM in court.
