Mammograms Won't Save Lives, U.S. Panel Now Says
Cancer experts reverse course, and say breast-cancer screening test should no longer be routine
THURSDAY, Jan. 24, 2002 (HealthDayNews) -- In a surprising about-face, a government panel of cancer experts now says mammograms don't appear to save lives and should no longer be routine.
The panelists, who review background information for the National Cancer Institute's (NCI) Web site, said seven earlier studies providing the empirical basis for screening mammography were weak and, taken together, don't support the practice.
That reverses the previous position of the group, the Physician Data Query (P.D.Q.) screening and prevention editorial board, which has held that the available data do support regular X-ray tests for breast cancer for women over 40.
Although the committee doesn't make clinical recommendations, the cancer institute follows its views closely. The institute is highly influential among practicing physicians, and the Web site is one many refer their patients to.
Dr. Peter Greenwald, the NCI's director of cancer prevention, said he hadn't seen the panel's final written report, which will be posted on the institute's Web site in the coming months.
However, Greenwald said, the NCI, which currently recommends screening mammography for women over 40, will weigh the document along with other evidence to determine if that stance merits revision. "Changing of public guidelines is a meticulous issue," he added. "This will be one piece of information that we'll take into account."
The decision was first reported today by the New York Times.
Donald A. Berry, chairman of the department of biostatistics at M. D. Anderson Cancer Center in Houston and head of the P.D.Q. panel, said screening programs lead to more treatment. "It isn't just the mammography, but it's the biopsies, the surgeries and the like," Berry told the Times.
"We know that screening is exquisitely fine at finding cancers," Berry said. "Therefore, it brings in patients and they demand treatment" that sometimes might be excessive and possibly harmful.
The panel's move vindicates two Danish scientists who have recently questioned the utility of screening mammography. Those researchers, Peter Gøtzsche, director of the Nordic Cochrane Center, and his colleague Ole Olsen, were roundly criticized for their first assessment of the seven studies, published two years ago in The Lancet, which found them deeply flawed.
Yet in a second review of the work, released last fall in the same journal, the Danish scientists reiterated their opinion that screening mammography doesn't save lives and may in fact jeopardize women who undergo unnecessary treatments for tumors that aren't life-threatening.
"We have not found evidence that screening saves lives," Gøtzsche said in an interview today. "We believe in our results, and we feel it doesn't look too good for screening mammography."
Gøtzsche said he has been stung by the often-cruel tenor of the responses to his and Olsen's papers, which were "very carefully peer reviewed" before being published. "It has been very tough. We have been subjected to a fair deal of ad hominem arguments -- that we never did a screening trial, that we are not surgeons, that we are not radiologists -- rather than people discussing academically what we have done and what our methods are," he said.
Both the National Cancer Institute and the American Cancer Society, another influential body, have supported screening mammography since the late 1990s. However, Scandinavian countries have been slower to adopt the practice, for reasons Gøtzsche believes are largely cultural. "In Europe we are much more skeptical toward annual health checks because there is a risk that you find something that really isn't anything but you think it is," he said. "The Americans are known for being more aggressive in health care."
Still, Norway has plans to initiate a national screening mammography program this year, though with some recent resistance, and Sweden is considering one as well. Denmark has also proposed such a system, but several counties have expressed skepticism about the initiative, Gøtzche said.
Experts said the science behind screening mammography in the United States has long been cloaked in a gown of politics. In 1997, a consensus panel for the National Institutes of Health said evidence didn't support screening for women under age 50. But the institute wound up recommending the tests for women 40 and older anyway.
Breast cancer groups and other women's health advocates have also been instrumental in keeping screening in place, experts said.
The American Cancer Society (ACS) has staunchly defended screening mammography for women over 40. Today the group continued to do so, despite the P.D.Q. panel's change of heart.
Even if the NCI were to stop recommending the practice, the ACS would continue to do so, said Robert Smith, director of cancer screening for the society. "The data are very persuasive."
Should a conflict of guidelines arise, patients will suffer, Smith added.
"I think it's certainly troublesome. I would hope under most circumstances that groups with differing conclusions based on data would find common ground that could translate into advice," he said.
But the ACS won't budge. "We are not prepared to toss this issue up into uncertainty," Smith said.
The P.D.Q. panel agreed that doctors shouldn't discourage women from seeking screening mammography if they want the procedure.