To screen for prostate cancer – or not to screen. That’s the question for increasing numbers of men. At the center of the debate is the PSA (prostate-specific antigen) test that was approved in 1986 by the Food and Drug Administration to screen for prostate cancer and detect the disease in the early stages.
In one sense, the test has been amazingly successful. The incidence of prostate cancer has soared over the last 20 years, largely due to the increasing use of the test as a better diagnostic tool than the DRE, or digital rectal exam.
But the controversy surrounds whether early detection is actually saving lives. Moreover, many contend that the risks of follow-up testing (repeated biopsies) may outweigh the benefits of screening.
Despite the debate, the PSA test is still considered the ‘gold standard’ for cancer detection. In the meantime, the debate has left some men in a quandary: What should they do?
What is the PSA Test?
Back to basics: The PSA Test is a blood test that measures the level of a protein known as prostate-specific antigen. While elevated PSA levels indicate prostate cancer, these PSA scores can also be the result of benign prostatic hyperplasia (BPH), prostatitis and other conditions. In any event, consider an elevated PSA an early detection or warning sign.
PSA is measured by nanograms per milliliter of blood, with most healthy men having under 4 ng/mL. According to the American Cancer Society, a PSA level between 4 and 10 indicates a 25% chance of it being prostate cancer. A PSA higher than 10 means there’s at least a 50% chance its prostate cancer.
Here are some advantages and drawbacks to the PSA test that men should be aware of.
Benefits of the PSA Test
- Prostate cancer can be detected by the test long before symptoms present themselves.
- The test detects cancer 5 to 10 years earlier than digital rectal exams (DREs).
- Early detection before the cancer has spread outside the prostate provides men with more treatment options and a better chance for a cure.
- Though this is a controversial claim by some experts, the test may contribute to significant reduction deaths from prostate cancer.
- The test is a quick, simple and painless procedure involving a medical staffer taking a sample of blood for testing in a lab.
Drawbacks of the PSA Test
- Significant number of false negatives. In 1 out of 5 cases, the PSA test comes back 'normal' with PSA levels in men with early prostate cancer.
- High rate of false-positive results. Two out of 3 of those with elevated levels of PSA do not have prostate cancer, so the test may cause undue worry.
- A false-positive result can lead to unnecessary follow-up testing that is more invasive, i.e., multiple biopsies.
- The test does not distinguish between prostate cancer and other prostate problems such as infection and BPH – again, leading to more false positives and unnecessary follow-up procedures.
- Men over the age of 75 may not benefit from the test because the prostate is generally very slow growing and treatment is unlikely to lengthen their lives.
What Should Men Do?
In most cases, early detection is very important for detecting prostate cancer and having more choices for treatment. So despite some drawbacks, the medical community generally and enthusiastically supports the PSA test.
The American Cancer Society and American Urological Association recommend an annual PSA test beginning at age 50, although more and more physicians recommend starting tests at 40, especially if there is a family history of prostate cancer. Likewise, African-American men are at higher risk for prostate cancer and should begin annual PSA screening at age 40 or 45.
It’s important for men to discuss the advantages and disadvantages of PSA testing with their physicians before having their PSA levels measured. Despite the debate, most experts believe early detection with the PSA test is the smart way to go -- at least until new tests are perfected.
'Silent Killer'
“(Prostate cancer) is a silent killer," said J. Brantley Thrasher, M.D., chairman of urology at the University of Kansas Medical Center in Kansas City, Kan., and spokesman for the American Urological Association (AUA), in the May-June 2006 issue of FDA Consumer magazine. "So most men with a nodule or elevated PSA aren't going to know it."
“(The PSA test) is an imperfect marker, but it's the best we've got,” he said.
Contributing statistics from John Hopkins Guide to Your PSA Test, 2008, and the American Cancer Society website.
Accuracy of PSA Tests: False Positives and Negatives Are Common
