Published March 27, 2013
Many studies have found the Prostate-Specific Antigen (PSA) test – the standard exam for prostate cancer – to be a unreliable screening method. Fortunately, a new report from the New York Times detailed how many more sophisticated prostate cancer tests will soon be on the market.
One such test involves mapping the genome of the cancer itself, in an attempt to distinguish between the most dangerous of tumors and the ones that are slow-growing and do not pose as much of a health risk. The current PSA test is not very accurate in differentiating between the two, often highlighting tumors that don’t need to be treated.
The United States Preventive Services Task Force actually recommended against the screening in late 2011, saying more men were harmed through unnecessary biopsies than men who were saved from dying of cancer.
“It’s not that screening doesn’t work; it’s that we haven’t done a great job of targeting treatments for the tumors that need it,” Dr. Matthew R. Cooperberg, an assistant professor of urology at the University of California, San Francisco, told the New York Times.
PSA tests work by measuring the amount of PSA – a protein produced by the prostate gland – in the blood. The new genetic testing would look for more than just the PSA protein, mapping multiple genes in the prostate, as well as other biological markers.
Two test developers, Genomic Health and Myriad Genetics, have created screening tests that analyze the genes of prostate cancers after biopsy, allowing doctors to gauge just how serious the tumor is. While the tests may come at a high price – maybe more than $3,000 – the companies say it could potentially reduce spending for unnecessary treatments by nearly $12 million, according to the New York Times.
According to Genomic Health, the company’s test – called the Genomic Prostate Score – will go on sale after Genomic Health releases supporting data on the test at the American Urological Association’s annual meeting in May.
Myriad Genetics conducted a study on its test, called Prolaris, which was published last year in the British Journal of Cancer. The research found that 19 percent of men with low-risk scores from the Prolaris test die from prostate cancer within 10 years, as opposed to 75 percent of men with high-risk test scores.
Myriad Genetics’ test has been available since last year, but sales of the product have remained low. Some doctors are still skeptical that genetic testing is the way to go, because they maintain these tests have yet to be adequately substantiated. Also, many men who test positive for prostate cancer still wish to receive treatment, even if they are recommended to forgo it based on their low test scores.
However, some experts believe these tests are the step in the right direction.
“Even if we can only convince 15 to 20 percent of men that we have enough confidence that they don’t need to be treated, that will be a big step forward,” Dr. Eric A. Klein of the Cleveland Clinic, who has worked with Genomic Health, told the New York Times.