A panel of cancer experts is recommending against testing for prostate-specific antigen (PSA), the most commonly used prostate cancer screen, in healthy men.
According to its review of the best available data, the U.S. Preventive Services Task Force (USPSTF) concludes that the potential harms of PSA testing — which include further, more invasive testing that may result in impotence and incontinence — outweigh any benefits in healthy men. The panel is expected to release on Tuesday a comprehensive report detailing the value of PSA testing, but the group’s draft recommendation was made public this week.
What does this mean for men who are concerned about prostate cancer? Here’s some information that can help you decide whether it’s right for you.
What is the PSA test?
The PSA test is a blood test that measures levels of prostate-specific antigen, a protein produced by cells of the prostate gland. It tends to show up on cancer cells, so higher levels of the antigen could be a sign of tumors. Men normally have low levels of PSA, but those levels may rise for reasons unrelated to cancer, which is why a high PSA level alone cannot be used to determine whether a man has cancer or some other benign condition.
What conditions other than prostate cancer can raise PSA levels?
There are many: benign growth of the prostate (the gland typically enlarges with age), infection or inflammation of the prostate, ejaculation, and riding a bicycle can all push PSA levels higher.
Who should get the PSA test?
Currently, there is no major medical group that recommends routine PSA testing, but millions of men over age 50 get it. The American Cancer Society, for example, does not have a specific recommendation for routine screening of healthy men without symptoms of prostate cancer, but it advises otherwise healthy men who have reason for concern about increased prostate risk to begin discussing screening with their doctors at age 50. That’s because the risk of prostate cancer tends to increase with age.
What did the USPSTF review find?
The task force focused on five clinical trials, including two large studies from the U.S. and Europe. The American study included more than 76,000 men and the European trial involved 182,000 men from seven countries; both trials compared outcomes in men who received routine PSA tests and those who did not. Overall, during a decade of follow-up, the data showed that there was no reduction in death rates from prostate cancer in men who got screened versus those who didn’t. In the European study, however, there was a slight benefit in mortality among men aged 55 to 69.
The USPSTF’s recommendation against routine screening applies only to healthy men without symptoms of prostate cancer. The panel didn’t look at the value of testing in men with other symptoms or in those who have already had prostate cancer.
Who follows the USPSTF’s advice?
Most medical groups follow the task force’s advice, and federal programs like Medicare rely on its conclusions when deciding whether to pay for screening tests. However, in 2009, when the USPSTF rolled back its recommendations for routine breast cancer screening — advising against routine mammograms for women under 50 — the federal government said it would continue paying for the test for women in their 40s.
Since the PSA test is a blood test, what’s the harm in getting tested?
The test itself doesn’t pose any danger, but it’s the decisions that doctors and patients make based on its results that can be potentially harmful. More than 33 million men over age 50 have already received a PSA test during routine physicals, and many have gone on to have biopsies, surgery or radiation treatment based on the results. But because the PSA test carries a relatively high false positive rate, many of these procedures — and their side effects — have been unnecessary.
For example, the USPSTF’s draft report notes that between 1986 and 2005, one million men had surgery, radiation or both because of positive PSA results, who would not have been treated if they hadn’t gotten the test. Up to 300,000 of them suffered from impotence, incontinence or both as a result of complications from these procedures, and 5,000 died soon after their surgeries.
Does this mean I don’t need to worry about getting screened for prostate cancer?
No. It’s important to be vigilant for any cancer, and screening is the best way to detect tumors early and intervene if you need treatment.
The question is what screening method is best? Unfortunately, the USPSTF report doesn’t make clear. There are other tests doctors use to detect prostate cancer, including digital rectal exams and ultrasound, but the task force found that these weren’t effective in picking up cancers either.
If you’re a healthy middle-aged male, you should discuss with your doctor when you need to begin screening for prostate cancer. Your risk of the disease increases with age, so it may make sense to wait before you begin regular screening.
Will doctors immediately follow the task force’s recommendations?
That’s hard to say. Like the USPSTF’s mammogram guidelines, the new PSA recommendations are already stirring controversy. Many prostate cancer experts are concerned that the advice against not screening healthy men could result in more cases of prostate cancer. They note that since PSA screening became widespread in the 1990s, death rates from the disease have dropped. Calling the recommendation “counterproductive,” and “wrong,” they are hoping that the advice does not cause more men to die from the disease.
Critics of the recommendation also note that potential risks like incontinence or impotence are not necessary outcomes of biopsies or other treatments, and that any such harms pale in comparison to having cancer. It is because of PSA screening, they argue, that doctors now see fewer cases of advanced prostate cancer that has spread to other organs.
The problem is not the PSA test itself, many doctors say, but that better strategies for dealing with positive or negative results are needed. That would help men benefit more from screening.