September 30th, 2010
10:14 AM ET
Amid the controversy over the age at which women should begin having mammograms, a study from Sweden supports starting breast cancer screening at age 40.
That conclusion goes against the U.S. Preventive Services Task Force issued guidelines recommending against mammograms for women ages 40 to 49. The announcement of those guidelines sparked an uproar among advocacy groups. Later, the task force said it had communicated the guidelines "poorly," and emphasized that women should still be able to choose to have mammograms at age 40 - it just shouldn't be automatic.
A study last week in the New England Journal of Medicine suggested that mammograms are not as effective in women over 50 as previously thought.
Research presented this week in the journal Cancer compared breast cancer mortality in areas of Sweden where women 40 to 49 had been invited for mammograms against those in which women in this age group had not. There were 7.3 million people included in the group that had mammograms in ages 40 to 49, and 8.8 million people in that sample that did not.
Researchers founded about a 26 percent reduction in the breast cancer death rate attributable to mammography. In order to save one life, 1,252 women had to be invited to get mammograms in the 40 to 49-year-old age.
The benefit appeared greater for women 45 to 49 than in the 40- to 44-year-old group.
Dr. Daniel Kopans, professor of radiology at Harvard Medical School, said that this study should "end the debate" about beginning mammograms at age 50.
"The age of 50 has never had any, scientifically supportable, importance for screening. The death rate is decreased for all women who begin screening at the age of 40," he said in a statement.
But CNNhealth.com conditions expert Dr. Otis Brawley, chief medical officer of the American Cancer Society, points out a flaw in the way that the Swedish study was done: Researchers did not take into account overdiagnosis. About 15 to 20 percent of localized breast cancers will not metastasize and don't actually need treatment, he said.
But the study's conclusion is nothing new, he said. The American Cancer Society still recommends screening for women ages 40 and up.
Still, the numbers saved aren't as large as one might think: Assuming there are about 22 million women in their 40s in the United States, by the Swedish study's conclusions, about 1,800 women would be saved if every one of them were screened.
In Brawley's overview of the mammography situation, he points out that even if all screening, treatment and awareness methods were to be used by all women in the United States, 450,000 women would still die of breast cancer over the next decade.
Bottom line: We need a better test and better treatment, he said.
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