New research is adding fuel to a fiery debate over who should be be screened for prostate cancer.
While proponents of the standard blood test used to detect signs of prostate cancer -- called the prostate-specific antigen, or PSA test -- maintain that it has saved thousands of lives, researchers in the Netherlands suggest that many men who are diagnosed with prostate cancer may have been better off never knowing they had the disease.
In a study of American men that lasted from 1985 and 2000, the researchers found that between 23 percent and 42 percent of prostate cancers identified by PSA testing are so slow-growing that they probably would never have posed a health threat.
In other words, most of these men would have lived a full life and died from another cause entirely, never knowing they had these slow-growing cancers. Instead, the authors maintain, the men were subjected to unnecessary treatment as well as the psychological trauma that goes along with a cancer diagnosis.
The study is published in the current issue of the Journal of the National Cancer Institute.
Dr. Michael Barry, medical director of the Center for Primary Care Innovation at Massachusetts General Hospital, notes in an accompanying editorial that he believes the researchers' estimates are probably low.
"The increased risk of getting a diagnosis of prostate cancer due to screening is much higher than for other cancers we screen for, such as cervical, colorectal, or breast cancer," Barry explained.
He argued that the benefits of screening, which he said have not been proved, need to be weighed against the emotional trauma of a low-risk cancer diagnosis and possibly unnecessary treatment.
On the other side of the debate are doctors like William Catalona. As director of the Clinical Prostate Cancer Program at Northwestern University Feinberg School of Medicine in Chicago, he has seen his fair share of prostate cancer. And while he acknowledged that a certain level of overdiagnosis occurs when it comes to prostate cancer testing, he said the benefits of the test far outweigh the risks of not having it done.
"I think that if [the authors] spent as much time trying to cure prostate cancer patients as I do, they might think again about discouraging efforts at early prostate cancer detection," Catalona said. "There is little doubt that PSA testing saves lives."
Next to skin cancer, prostate cancer is the most common form of cancer among men in the United States, according to statistics from the American Cancer Society. ACS estimates that one out of every six men in the United States will be diagnosed with prostate cancer at some point in their lives.
And it can be deadly. About 28,660 men died of prostate cancer in 2008, according to the National Cancer Institute. Catalona said this deadly possibility warrants annual PSA testing for all men 40 and older.
"The age-specific prostate cancer-specific death rate in the United States has decreased by 37.5 percent in the PSA screening era, and even the naysayers estimate that 45 percent to 70 percent of this decrease is probably due to PSA testing," he said.
Dr. Robert Reiter, professor of urology and director of the Prostate Cancer Program for the UCLA Health System, argued that the harms of diagnosing some patients who may not need treatment is far outweighed by the benefit of catching some deadly cancers early.