Prostate cancer screening debate continues

By Dr. Ananya Mandal, MDMar 15 2012

Routine tests that help detect prostate cancer actually do reduce the risk of death from the disease, researchers said. Screening is done with a simple blood test that measures levels of prostate-specific antigen, or PSA.

Those who were screened for PSA, a protein associated with the cancer at high levels, had a 21 percent lower risk of dying from the disease than those who weren’t screened, according to the study published today by the New England Journal of Medicine. The researchers tracked more than 160,000 European men older than 50 for a median of 11 years.

The study researchers estimated that to prevent one death from prostate cancer, more than 1,000 men would need to be invited for testing and 37 cancers would need to be detected. Screening for PSA didn’t result in a lower risk of death from any cause over the period of the study, they found. Treatment for the cancer, which grows slowly in most men, may result in complications including bacterial infections, incontinence and impotence. What's more, only two of the eight countries involved in the study saw fewer prostate cancer deaths, while the others six did not.

“More information on the balance of benefits and adverse effects, as well as the cost-effectiveness, of prostate-cancer screening is needed before general recommendations can be made,” wrote the researchers, led by Fritz Schroeder at the Erasmus University Medical Center in Rotterdam, the Netherlands.

In addition according to the U.S. National Cancer Institute the PSA test can miss the disease, or give a positive reading as a result of benign prostate conditions. Almost 242,000 American men will be diagnosed with prostate cancer this year, and about 28,000 will die, the institute estimates.

Controversy arose when a U.S. panel said in a draft report in October that PSA screening doesn’t save sufficient lives to justify exposing men to risks of death, incontinence and impotence. The Health and Human Services Department’s Preventive Services Task Force recommended against PSA tests for men who don’t have symptoms that are “highly suspicious for prostate cancer.”

Three years ago, doctors with the European Randomized Study of Screening for Prostate Cancer (ERSPC) reported that PSA testing, found 1,410 men would need to be screened to prevent one prostate cancer death. In the process, 47 men would be diagnosed with cancer, risking side effects from treatment without benefiting.

The PSA test is given annually to millions of American men, but more and more experts question whether it's worth the money and the false alarms it triggers in about half the people flagged by the test.

Dr. Otis Brawley, chief medical officer of the American Cancer Society, said the European study is actually eight studies in eight countries, and only in Sweden and the Netherlands did PSA testing significantly reduce the risk of death from prostate cancer. “Screening saves lives if you live in the Netherlands and Sweden, but not the other six places,” he told Reuters Health in a telephone interview. One factor that may have skewed the Swedish data, he said, is that men who were screened were treated at an academic medical center, while men in the control group who developed cancer were treated elsewhere in the community. That alone might account for the lower mortality rate in the PSA population. In all, there were 299 prostate cancer deaths in the screening group compared to 462 in the control group that was not screened.

Brawley said PSA testing is being widely promoted because “there's a huge profit in screening and treatment” for prostate cancer, even though most studies have failed to show that screening saves lives.

Schroder said guidelines from the National Comprehensive Cancer Network, the European Association of Urology, and American Urological Association “provide a sensible recommendation: men who wish to be examined need to be carefully informed with balanced views and answers to their questions before they take a decision to be screened.”

In an editorial, public health expert Dr. Anthony Miller of the University of Toronto, said it would be “unwise” to intensify PSA testing. “I think it would be advisable to follow the preliminary recommendations of the U.S. Preventive Services Task Force,” he wrote.