New study won’t end debate on PSA test for prostate cancer

Whether or not men should have a simple blood test to look for hidden prostate cancer has long been a controversial and confusing issue. A new study from Europe does little to resolve it.

Dr. Harvey Simon, editor of the Harvard Men’s Health Watch, has written thousands of words, and counseled many of his patients, about PSA testing. In the March 2012 issue, he discusses his own decision not to have routine PSA testing.

In this study of 162,000 men, those tested for prostate-specific antigen (PSA) were less likely to have died of prostate cancer over the course of the 11-year study than men who didn’t have the test. Deaths from any cause, however, were the same in both groups—meaning that the test didn’t save lives.

The researchers (and most news reports) highlighted the 21% relative reduction in deaths due to prostate cancer. That sounds like a lot. But here’s what it means in absolute terms: among men who had the PSA test, there were 4 deaths per 10,000 men per year, compared to 5 deaths per 10,000 men per year in the group that didn’t have the PSA test. The study was published in the New England Journal of Medicine.

What can be bad about a test for cancer?

On the surface, a relatively inexpensive test that can detect cancer in its earliest (and most treatable) stage looks like a winner. But the devil is in the details:

• Many men with prostate cancer are elderly and have no health problems related to the cancer. They may have other, more important health problems. For them, early detection of prostate cancer usually isn’t helpful.
• Prostate cancer often grows very slowly. Most men who have it die of something else. Some men live with the side effects of treatment—notably impotence and incontinence—for a cancer that would have had no effect on the length or quality of their lives.
• Since a high PSA does not always indicate cancer, a biopsy is needed to find out why the PSA is high. Prostate biopsy isn’t the most pleasant of procedures and it can be accompanied by complications such as bleeding or infection.
• Studies have not proven that PSA testing saves lives.

The U.S. Preventive Services Task Force, an independent panel of experts whose recommendations help define high-quality health care for most Americans, has long recommended that men over age 75 not get routine PSA tests unless there is a good reason to do so. Last fall, the task force issued a preliminary recommendation (now awaiting public comment) saying no to routine PSA testing for all men.

Rethinking the PSA test

The new study is likely to strengthen the task force’s advice against yearly PSA testing. My own view is that we should reconsider the widespread use of PSA testing, especially the yearly screening that is common in the United States. To be worthwhile, a screening test should have clear benefits that strongly outweigh any risks. That hasn’t been proven for PSA testing.

This makes PSA testing a most individual decision. As my colleague Dr. Harvey Simon writes in the Harvard Men’s Health Watch, all men should talk about PSA testing with their doctors. Learn the risks, benefits, and limits of this test. Then decide with your doctor whether you should have the PSA test at all and, if so, how often.