The idea that finding cancer early can harm instead of help is a hard one to understand. But it’s at the heart of a government panel‘s draft recommendation that those PSA blood tests should no longer be part of routine screening for healthy men.
The U.S. Preventive Services Task Force examined all the evidence and found little if any reduction in deaths from routine PSA screening. But it did conclude that too many men are diagnosed with tumors that never would have killed them and suffer serious side effects from resulting treatment.
That recommendation isn’t final — it‘s a draft open for public comment. But it goes a step further than several major cancer groups including the American Cancer Society, which urges that men be told the pros and cons and decide for themselves.
The new advice is sure to be hugely controversial. Already some doctors are rejecting it.
“We all agree that we’ve got to do a better job of figuring out who would benefit from PSA screening. But a blanket statement of just doing away with it altogether ... seems over-aggressive and irresponsible,” said Dr. Scott Eggener, a prostate cancer specialist at the University of Chicago.
In the exam room, explaining the flaws in PSA testing has long been difficult.
“Men have been confused about this for a very long time, not just men patients but men doctors,” said Dr. Yul Ejnes, a Cranston, R.I., internal medicine specialist who chairs the American College of Physicians‘ board of regents.
He turned down his own physician’s offer of a PSA test after personally reviewing the research.
“There‘s this dogma ... that early detection saves lives. It’s not necessarily true for all cancers,” Ejnes said.
That‘s an emotional shift, as the American Cancer Society’s Dr. Len Lichtenfeld voiced on his blog on Friday.
“We have invested over 20 years of belief that PSA testing works. ... And here we are all of these years later, and we don‘t know for sure,” Lichtenfeld wrote. “We have been poked and probed, we have been operated on by doctors and robots, we have been radiated with fancy machines, we have spent literally billions of dollars. And what do we have? A mess of false hope?”
Too much PSA, or prostate-specific antigen, in the blood only sometimes signals prostate cancer is brewing. It also can mean a benign enlarged prostate or an infection. In fact, most men who undergo a biopsy for an abnormal PSA test don’t turn out to have prostate cancer.
Screening often detects small tumors that will prove too slow-growing to be deadly — by one estimate, in 2 of every 5 men whose cancer is caught through a PSA test. But there‘s no way to tell in advance who needs treatment.
“If we had a test that could distinguish between a cancer that was going to be aggressive and a cancer that was not, that would be fabulous,” said Dr. Virginia Moyer of the Baylor College of Medicine, who chairs the task force, an independent expert group that reviews medical evidence for the government.
About 1 in 6 U.S. men will be diagnosed with prostate cancer at some point in their life. Yet the cancer society notes that in Western European countries where screening isn’t common, 1 in 10 men are diagnosed and the risk of death in both places is the same. In the U.S., about 217,000 men are diagnosed with prostate cancer each year, and 32,000 die.
Why not screen in case there‘s a mortality benefit that studies have yet to tease out? The task force outlined the problem with that: —Up to 5 in every 1,000 men die within a month of prostate cancer surgery, and between 10 and 70 more suffer serious complications.
—At least 200 to 300 of every 1,000 men treated with surgery or radiation suffer incontinence or impotence.
—Overall, Moyer said 30 percent of men who are treated for PSA-discovered prostate cancer suffer significant side effects from the resulting treatment.
Among the questions sure to be raised during the public comment period are how doctors should advise men with prostate cancer in the family or black men, who are at increased risk.
PSA testing also is used to examine men with prostate symptoms, and to check men who already have had prostate cancer. The new recommendation doesn’t affect those uses.
Congress requires that Medicare cover PSA tests, at a cost of $41 million in 2009. Other insurers follow Medicare‘s lead, especially in light of conflicting recommendations.
Nor does the new recommendation mean that men who want a PSA test can’t have one. If the rule is adopted — something the government will review once the task force hears comments and finalizes its guidance — it would just advise against doctors pushing it routinely.
“The truth is that like so many things in medicine, there‘s no one-size-fits-all,” said Dr. Michael Barry of Massachusetts General Hospital who heads the Foundation for Informed Medical Decision-Making that backs ways to help patients make their own choices.
美종양학계, 전립선특이 항원검사 퇴출에 반발
미국 비뇨기학회와 종양 전문의들은 전립선암 표준검사법인 전립선특이항원(PSA) 검사가 불필요하다는 질병예방특별위원회(USPSTF )의 결정에 반발하고 나섰다고 뉴욕 타임스와 헬스데이뉴스 등이 8일(현지시간) 보도했다.
USPSTF는 7일 PSA검사가 전립선암 사망위험을 낮추어 주지 못하고 있으며 따라서 건강한 남성은 PSA검사를 받을 필요가 없다는 결론을 내렸다. USPSTF는 독립기관 이지만 미국 정부가 선정한 의사와 과학자들로 구성되고 정부로부터 연구비를 전액 지원받고 있어 사실상 정부기관이다.
PSA검사는 전립선 특이항원의 혈중수치를 측정하는 전립선암 표준검사법으로 사용되고 있지만 전립선암 특이성(specificity)이 낮고 허위양성률(false positive ra te)이 높아 불필요한 조직검사로 이어질 수 있기 때문에 효율성을 둘러싸고 논란이 되어왔다.
미국비뇨기학학회는 PSA검사가 득보다 실이 많다는 USPSTF의 결정이 결국 득보다 더 큰 실을 가져올 것이라고 즉각 반발했다.
하버드 대학 의과대학 브리검 여성병원 영상종양실장 앤서니 다미코 박사도 잘못 내려진 결정이라면서 65세 이하 건강한 남자라면 매년 PSA검사를 받도록 권할 것 이라고 말했다.
그는 PSA 검사 결과에 따른 과잉치료(overtreatment)가 문제가 되어왔지만 정확 한 검사결과가 나오도록 노력하면 이러한 문제는 해소될 것이라고 강조했다.
정확한 결과를 얻기 위해서는 검사 전 섹스, 자전거 타기, 승마, 대장내시경 검사 등을 피해야 하고 방광이나 전립선 감염이 있으면 염증이 해소된 뒤 최소한 1개월 후에 검사를 해야 한다고 그는 지적했다.
미국 암학회(ACS)의 오티스 브롤리 박사는 수검자에게 PSA검사의 득과 실을 먼저 충분히 설명한 후 수검자 자신이 검사를 받을지를 결정하게 해야 할 것이라고 말 했다.
듀크 대학 메디컬센터 비뇨기외과 전문의 라이오넬 바네스 박사는 전립선암이 폐암 다음으로 남성의 암 사망률 2위를 차지하는 만큼 전립선암 사망률을 조금이라도 낮출 수 있는 PSA검사를 없앤다는 것은 바람직하지 않다고 말했다.
USPSTF는 2009년에도 40세 이하 여성은 유방암 표준검사법인 유방X선 검사를 매 년 받을 필요가 없다는 결론을 내려 커다란 논란을 일으킨 일이 있다.