Screening Debate Typifies Prostate Cancer Uncertainties
FRIDAY, Aug. 10 -- Though prostate cancer makes the news a lot, much of the information seems conflicting or inconclusive, leaving men with few absolute answers.
Which treatment is most effective? Which has the fewest side effects? And who might benefit most from screening for prostate cancer?
The dilemma posed by screening perhaps typifies the haze surrounding prostate cancer issues.
"The problem with screening is we know that you have to screen a lot of people and treat a lot of people to prevent one death," explained Dr. Ian Thompson, director of the Cancer Therapy and Research Center at the University of Texas Health Science Center in San Antonio. "Right now, you have to screen at least 1,000 men and treat between 20 and 50 to prevent one death. That person unequivocally benefits from screening, but at the same time, many men were treated who didn't need it."
That's key because the risks of screening aren't trivial, he said. The possibility of a false positive is significant, and that finding then leads to a biopsy, which can cause excess bleeding or infection. It's also possible to find a cancer that may have been inconsequential, so screening can lead to overtreatment.
Complications from treatment also may include surgical complications, urinary incontinence and sexual side effects.
"Now you have a man who has to take Viagra or who becomes sexually inactive, or who has urinary incontinence or other complications, and those are significant," Thompson said. "And, while those complications may seem small compared to saving a life, there are far more people affected by complications than people saved."
Ruth Etzioni, a biostatistician and researcher at the Fred Hutchinson Cancer Research Center in Seattle, agreed.
"The reason why people can't come to an agreement about screening [for prostate cancer] is that it's not all good," Etzioni said. "It's costly and it can harm many more men than it's saved."
"Older men won't benefit from prostate cancer screening," Etzioni said. "They're much more likely to die of another cause. There really is a consensus that older men shouldn't be screened. But, there are still doctors performing the test in older men or older patients who are asking for it."
For younger men, there's no consensus on what to do, said both Thompson and Etzioni.
The latest recommendation from the U.S. Preventive Services Task Force is that there's not enough credible information available to recommend screening for prostate cancer with the prostate-specific antigen (PSA) test for any man, regardless of age.
Not everyone agrees with that recommendation, however. The American Society of Clinical Oncology advises men with a life expectancy of more than 10 years to talk with their doctors about their own individual risks and benefits from a PSA screening test. For men with a life expectancy of less than 10 years, the organization believes that the risks of the PSA test probably outweigh its benefits.
Men with a higher risk for prostate cancer may benefit from screening with the PSA test, according to Thompson. One factor that increases risk is having first-degree relatives -- father, brother, son -- with prostate cancer. The more relatives with the disease, the greater a man's risk. The other significant risk factor is race. Blacks have double the risk for prostate cancer, compared with whites, Thompson said.
However, most people who develop prostate cancer have no risk factors at all, he said.
Etzioni said it's important to keep the odds of dying from prostate cancer in context.
"The chance that you'll die of prostate cancer is rare," she said. "The chance that something else will kill you is much higher." Men's health would be better served, she said, if they spent more time exercising and eating healthy.
Thompson said he wished men would do at least the same amount of due diligence in deciding whether to get a prostate cancer screening as they do when they're going to buy a major appliance or a car.
"The take-home message is what really ought to happen is that people should become educated," he said.
That advice also holds true when men with prostate cancer have to choose which treatment is best for them, he said. Common options include active surveillance, surgery, radiation and hormone therapy.
When it comes to choosing an individual treatment, both Thompson and Etzioni said that most of the common treatments appear to be similarly effective so the decision may come down to the potential side effects of each treatment.
"There are important side effects from treatment that can affect quality of life, and they're not infrequent," Etzioni said.
Often, though, that decision "may be more of a gut feeling than an intellectual decision," Thompson said.
For men with slow-growing cancer, both experts said that active surveillance -- sometimes called watchful waiting -- is often a reasonable alternative to other treatments. The condition is monitored closely but not treated unless it progresses.
Men with more aggressive cancers may need to combine treatments to get the best results, Thompson said. Those who choose radiation to treat such cancer, he said, usually have better outcomes when they also have hormone therapy. For those who choose surgery for an aggressive cancer, results will probably be better if radiation is added to the treatment, he noted.
The American Urological Association Foundation has more on prostate cancer.
A companion article looks at how one man dealt with treatment options.
Posted: August 2012
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