New Blood Test Can Diagnose Severe BPH
Researchers have developed a new blood test that can distinguish severely symptomatic BPH from BPH that occurs with few if any symptoms, even if men have prostate cancer. The assay measures serum levels of a protein called JM-27.
In serum, JM-27 concentrations are decreased in men with severe BPH, the investigators reported in the Journal of Urology (2007; published online ahead of print). Their study revealed that, at the level of genetic expression, BPH exists in two forms. One form produces mild or no symptoms and is less likely to lead to bladder and other urinary tract damage; the other form is highly symptomatic and associated with increased potential damage to the bladder.
The findings are based on a study involving three groups of patients: 29 with asymptomatic BPH (American Urological Association symptom score of 15 or less), 39 with symptomatic BPH (AUA symptom score of 16-32), and 17 with confirmed prostate cancer. The assay had 90% sensitivity and 77% specificity for distinguishing between the two forms of BPH. The positive and negative predictive values were 74% and 91%.
“Our experiments show that the expression of this marker is related to the presence of the severe form of BPH and not to the size of the pros-tate or to the presence of prostate cancer,” said investigator Robert Getzenberg, PhD, professor of urology research at Johns Hopkins School of Medicine in Baltimore. “We might be able to prevent some bladder problems if we attack the problem earlier in the course of the disease. So, maybe we can stratify patients better and use this marker to know if a patient will respond to an alpha blocker, 5-alpha reductase inhibitor, or whether combination therapy may be best.”
JM-27 may enable clinicians to identify a subset of men who might benefit from earlier therapy, Dr. Getzenberg said. The marker also may provide a way to follow BPH patients and determine treatment efficacy.
“This is a provocative report detailing a potential new means of identifying patients with symptomatic BPH, and a significant addition to the urological literature with much scientific promise,” Kevin T. McVary, MD, of Northwestern University's Feinberg School of Medicine in Chicago, wrote in an accompanying editorial. He cautioned that the findings are preliminary so “a heavy dose of skepticism is warranted.”
He pointed out that Dr. Getzenberg's group did not show the status of men with inflammation: “Since a significant number of men with symptomatic BPH may have concomitant inflammation, it is possible that JM-27 may not be able to separate symptomatic BPH from inflammation.”