Thứ Tư, 12 tháng 10, 2011

Prostate Test Finding Leaves a Swirl of Confusion

Bruce Powell/University of Chicago Medical Center, via Associated Press
For men living with a diagnosis of prostate cancer, the news that the P.S.A. test does more harm than good has been unsettling and confusing.
After all, that is the test that first led to their diagnosis — and, often, a painful and traumatic course of treatment.
And now they tell us it doesn’t work?
“You will find mixed opinions from those of us who had to deal with it,” said a 78-year-old man from Boston who was left impotent and incontinent after his prostate was removed 11 years ago. “My current feeling is not anger; it’s sadness that I probably made the wrong choices and the consequences were both negative and not expected.” (He and another man quoted in this column asked not to be identified.)
This week, the United States Preventive Services Task Force is expected to announce its recommendation against routine testing for blood levels of prostate-specific antigen, the protein that can be a signal of prostate cancer. The panel says research shows that over all, the test does not save lives and leads to unnecessary surgery and radiation treatment for slow-growing cancers that would never have caused harm. As for faster-growing, invasive cancers, there’s no proof that P.S.A. tests and earlier treatment offer any overall benefit.
Many men do remain convinced that the test saved their lives by helping their doctors detect cancer in its earliest stages. But others are now left second-guessing their decisions, questioning a medical system that pressured them not only to undergo screening, but to be treated aggressively once cancer was detected.
Ten years ago, several doctors urged William Lewis of Washington, now 69, to have his prostate removed after a spike in his P.S.A. levels led to a biopsyand a diagnosis of cancer. But his own research led him to a “watchful waiting” program at Johns Hopkins School of Medicine, where he now undergoes regular checkups and biopsies to make sure his cancer hasn’t progressed.
“My urologist said, ‘Definitely prostatectomy,’ as did other people,” Mr. Lewis said. But “absolutely nothing has showed up that would suggest treatment is in order.
“A lot of people are living with prostate cancer not knowing it and never knowing they have it,” he went on. “It’s just a common fact of life for men.”
But doctors are divided about when to recommend watchful waiting. The decision can be guided by an indicator called the Gleason score, a measure of the aggressiveness of the cancer found in a biopsy, but there is often disagreement about how to care for men whose scores are in the middle — neither highly aggressive nor probably not aggressive. In addition, the biopsy process itself is imprecise; a standard “12-core biopsy” gives information about only one three-thousandth of the prostate, says Dr. Eric Klein of the Cleveland Clinic. According to research at Johns Hopkins, staging and grading mistakes occur in about 20 percent of specimens.
“You can’t be sure that even if you’ve found a cancer that is low-grade and seems innocuous that you haven’t missed a more aggressive cancer,” he said. “That’s the major limitation that leads to patient and family and physician uncertainty about who can be watched and who can’t be watched.”
Bill Murin, a 67-year-old retired university professor in Racine, Wis., had prostate surgery after a spike in his P.S.A. led to a cancer diagnosis when he was 64. He said that his recovery had been “satisfactory,” and that he had been able to resume his sex life with the help of Viagra.
He says he would probably make the same choices if he had it to do over again.
“There’s no parallel universe, unfortunately,” he said, adding:
“Psychologically, when someone looks you in the eye and says you have cancer, your immediate reaction is ‘Get this damn thing out of here.’ I’m not sure I’d be brave enough to undergo the watchful waiting.”
Other patients say the problem is not the screening test but the way some doctors react to it.
“There is still a lot of pressure to just get it out,” said a 48-year-old man who received his diagnosis two years ago after an elevated P.S.A. result. “The more I’ve learned about this in the last two years, I’m shocked at how urgently my initial urologist pushed for treatment. I’m really unhappy about this, and I think there are some major problems with the culture and the pressure.”
Instead, the man enrolled in a watchful waiting program in Seattle, changed his diet and lost weight. His P.S.A. levels have dropped and subsequent biopsies have not detected cancer.
“The newer thinking is that cancer doesn’t always have the same trajectory; it’s not always that aggressive,” he said. “Why put men in the situation where they have to make this decision if they don’t need to?”
Timothy Bartik, 57, an economist in Kalamazoo, Mich., did his own research and believes that the data support P.S.A. testing, particularly for younger men. He had his prostate removed in March after getting an elevated reading, followed by a biopsy that showed he had cancer. After surgery, he learned the cancer was slightly more aggressive than the biopsy had suggested.
“You have to weigh probabilities,” he said. “You have to accept that there’s no certainty. Ideally, you’d have a great test that would tell you much more precisely what your chances are.”

nyTimes

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