Risky line between tests and treatment
Prostate cancer is riddled with indignities that cut to the core of manhood. It begins with a doctor’s request to bend over for a digital rectal exam and can end in impotence and diapers. Very little in between is clear-cut.
Even being tested in the first place is controversial. The American Cancer Society and the American Urological Assn. recommend dual tests, a rectal exam and a prostate specific antigen, or PSA, blood test every year for men older than 50, and five to 10 years sooner for African Americans and men with a family history of the disease.
But the American College of Physicians doesn’t go beyond recommending counseling about possible risks and benefits of testing. And the U.S. Preventive Services Task Force found insufficient evidence to recommend either for or against routine screening.
“We don’t know if having a PSA test helps men live longer or live better,” says Dr. Timothy Wilt, professor of medicine at the Minneapolis VA Center for chronic disease outcomes research.
The line between lives saved by early detection and lives blighted by unnecessary treatment is still fuzzy. Testing often leads to treatment. And though standard treatments have high rates of cure, they also have mutilating side effects -- incontinence and impotence.
“If everyone over 50 were screened and biopsied, we might end up diagnosing up to a quarter of men,” says Dr. Laurence Klotz, urology professor at the University of Toronto. In the United States, that would translate to almost 10 million men over the age of 50 being presented with a prostate cancer diagnosis. As it is, not every man is screened, but 234,460 men are expected to be diagnosed with prostate cancer this year; and an estimated 27,350 men will die of the disease.
Worse, PSA testing cannot always distinguish between a slow-growing cancer that is destined to be harmless and an aggressive cancer that could kill. At Johns Hopkins Medical Center, one pathology analysis of 300 surgically removed prostates found that 25% to 33% of the tumors were so small as to be clinically insignificant. Other studies have put the risk of over-treatment at anywhere from 16% to 56%.
“How many men can have their prostates sacrificed on that altar to save those 30,000 men? It’s a very difficult question,” says Mark Scholz, a Marina del Rey oncologist specializing in prostate cancer.
“The controversy over screening will rage for many years,” says Peter Carroll, urologist at UC San Francisco. “A lot of it would go away if we stopped linking diagnosis with immediate treatment.”
Wilt is a decade into a 15-year-study of 731 men with prostate cancer to see if men who have their prostates surgically removed live longer than men with the same risk who forgo treatment. About half of them had a radical prostatectomy to remove the organ; the other half are monitored without treatment. If doing nothing gets results equal to doing something, the thinking goes, then testing is futile.
Study results won’t be available until about 2010. It’s likely, he says, that men with fewer than 15 years of life expectancy won’t benefit much from testing. Even so, in one recent study, about 94% of men with low-grade prostate cancer, their risks low enough to be candidates for waiting, received radical treatment in 2002, according to a report in the December 2003 Journal of Urology.
Still, the test will benefit some men. Since the PSA test was approved for help in diagnosing prostate cancer in 1994, more younger men are being diagnosed with less advanced cancer, and the death rate from the disease is dropping. About one in six men will be diagnosed with prostate cancer in his lifetime, but only about one in 34 will die of the disease, according to the American Cancer Society.
Diagnosed men in their 50s and 60s, and older men who are vigorous, healthy and the recipients of favorable longevity genes, face tough trade-offs when confronted with a test result showing early, low-risk disease. They’re the ones who may live long enough to give even a slow-growing cancer time to kill.
They’re the ones forced to roll the dice and make a decision.
