PSA Test: The Recent Controversy
By Heather Maloney
Beth Israel Deaconess Medical Center Staff
The recent recommendation by the
U.S. Preventive Services Task Force (USPSTF), a government panel, against routine PSA-based screening for prostate cancer is sparking a great deal of debate in medical circles - and likely causing confusion for patients.
The USPSTF report, published October 7 in the
Annals of Internal Medicine, concluded that screening men using the PSA test does not prolong life for the average American man, and "is associated with harms related to subsequent evaluation and treatments, some of which may be unnecessary."
The USPSTF had previously recommended against routine PSA screening in men older than 75. The new recommendation extends this to all men.
Already, the new guidelines are causing quite a bit of debate.
The American Cancer Society has not endorsed the recommendation and has stated that it wants to review the data.
Several physicians and scientists have questioned why prostate cancer oncologists and urologists were not included on the panel. And many medical experts claim the report over-interprets premature data from flawed clinical trials.
Dr. Martin Sanda, Director of the
Prostate Cancer Center at
Beth Israel Deaconess Medical Center, points out that the panel's summary and recommendations have overlooked the impact that PSA testing has had on reducing deaths from prostate cancer over the last 20 years.
"Data from the
CDC has shown that deaths from prostate cancer were reduced more than for any other common cancer during the period from 1980 to 2005, a time when the most significant new advancement in prostate cancer treatment was earlier diagnosis due to PSA testing," Dr. Sanda says. "And the USPSTF summary report did not consider one important fact: that since the advent of PSA testing, prostate cancer deaths have dropped from over 50,000 per year 20 years ago to less than 30,000 in 2010."
And most cancer specialists agree that cancer care, including screening, should not be viewed as one-size-fits-all.
"There has been consensus for some time that it is wrong to screen every man without considering possible other health problems, and many panels have agreed that men should have more than a 10-year life expectancy to undergo screening," explains Dr. Sanda. "Ironically, the USPSTF recommendations are based in large part on two incomplete studies in which the average follow-up was less than 10 years."
The PSA blood test measures the amount of prostate-specific antigen, a protein produced by the prostate and released into the bloodstream. If prostate cancer develops and grows, PSA levels rise. However, normal results on a PSA test don't always mean that cancer is absent - and abnormal results don't always indicate that the patient has cancer. Other factors, like an infection or benign enlargement of the prostate, can also cause PSA levels to rise.
Most experts agree that PSA testing isn't perfect, but right now it is the only test for prostate cancer that is widely available. And the test does provide information that can be useful, especially when a patient has other risk factors, such as a family history of the disease.
"I firmly believe that screening for prostate cancer saves lives," says
Dr. J. Jacques Carter, a primary care physician at BIDMC. "While many men with low-grade disease will never need to be treated, men who have high-grade disease will likely die prematurely if an early diagnosis is not made."
"Many of us who advocate for screening men who are at high risk, such as African-Americans or men with strong family histories of prostate cancer, feel that the controversy about this issue needs to be viewed in a different light," Dr. Carter says. "After all, it the over-diagnosis and over-treatment of low-grade prostate cancers that disturbs most opponents of screening."
American Urological Association (AUA) has already issued a response to the USPSTF recommendation, stating: "We are concerned that the Task Force's recommendations will ultimately do more harm than good to the many men at risk for prostate cancer both here in the United States and around the world.
"The AUA's current clinical recommendations support the use of the PSA test, and it is our feeling that, when interpreted appropriately, the PSA test provides important information in the diagnosis, pre-treatment staging or risk assessment and monitoring of prostate cancer patients."
"Right now, the PSA test is the best tool that we have," Dr. Carter says. "I think the USPSTF recommendations will lead to more confusion for patients and perhaps lead to late diagnosis in some men with aggressive disease."
Above content provided by Beth Israel Deaconess Medical Center. For advice about your medical care, consult your doctor.
Posted October 2011