A standard prostate cancer test, done in a different way, may help doctors find deadly tumors and cure the disease, a study says.
Doctors currently use a single value for the PSA test, which measures prostate-specific antigen. Patients with a result higher than four nanograms per milliliter of blood are told they need a biopsy. A study now suggests that testing how fast PSA levels rise over time, a factor known as velocity, may better indicate the presence of dangerous tumors.
About 90 % of men who had a low PSA velocity before their cancer was diagnosed were still alive 25 years later, compared with 54 % with faster rising PSA.
The finding is important because the current test often misses cancer that later kills while spotting slow-growing tumors that may be harmless, researchers said.
Early treatment with surgery and drug therapy can cure the disease.
"What we need to do is not diagnose more cancer, we need to diagnose cancer smarter," said H. Ballentine Carter, the lead researcher and director of adult urology at Johns Hopkins University School of Medicine, in a telephone interview. " This suggests PSA velocity is useful for identifying cancers that are going to kill people, at a time when it's still curable."
It may make sense for men to get their first PSA test while they are in their 40s, rather than the currently recommended age of 50, so they have a baseline number for future comparisons, Carter said.
More than 230,000 American men are diagnosed with prostate cancer each year, making it the most common cancer in men. It's often a slow-growing disease, killing less than 30,000 men annually. About 60,000 men undergo radical surgery to remove the prostate gland each year in the U.S. Previous studies showed surgery can cut death rates in half.
While the latest findings, published tomorrow in the Journal of the National Cancer Institute, are intriguing, more study is needed before doctors change how they diagnose and treat men with prostate cancer, said Durado Brooks, director of prostate and colon cancer at the American Cancer Society.