Tuesday, February 17, 2009
Scientists have made a discovery that could lead to a simple test to help determine which men who have prostate cancer require treatment and which do not.
More than 180,000 men receive a diagnosis of prostate cancer each year in the United States, making it the second-leading form of cancer among men after skin cancer. But whether to get treated is often a tough decision. Prostate cancers often grow very slowly, meaning many men could simply live with the disease without shortening their life span. And the treatments can cause serious complications, including incontinence and impotence. On the flip side, prostate cancer does kill more than 28,000 men each year.
In the new research, published in today's issue of the journal Nature, researchers at the University of Michigan analyzed 1,126 molecules produced by the body in 262 samples of tissue, blood or urine from men who were healthy or had early-stage prostate cancer or prostate cancer that had spread.
The researchers found that one substance, sarcosine, was particularly elevated in men with advanced prostate cancer. In fact, it appeared to be a better indicator of advancing prostate cancer than testing for prostate-specific antigen (PSA), which is what doctors primarily rely on at present.
Because sarcosine can be detected in urine, it could potentially be used for a simple urine test to identify men requiring treatment.
In addition, tests indicate that sarcosine may play a direct role in making prostate cancer more aggressive. When the researchers added the substance to benign prostate cells in the laboratory, the cells became invasive. So drugs that block its activity could potentially be used to improve treatment.
The researchers cautioned, however, that much more research is needed to confirm the findings and determine how well it would work as a screening test. But if the initial findings hold up with further study, the substance could help save a lot of men from unnecessary treatment and alert others that they need to act.
-- Rob Stein
This article was first published online in the Checkup blog. For other material from the Checkup, see Page F2. Or log on to http://voices.washingtonpost.com/checkup.