One of the most respected and influential groups in the continuing breast-cancer screening debate said Tuesday that women should begin mammograms later and have them less frequently than it had long advocated.
The American Cancer Society, which has for years taken the most aggressive approach to screening, issued new guidelines Tuesday, recommending that women with an average risk of breast cancer start having mammograms at 45 and continue once a year until 54, then every other year for as long as they are healthy and expected to live another 10 years.
The organization also said it no longer recommended clinical breast exams, in which doctors or nurses feel for lumps, for women of any age who have had no symptoms of abnormality in the breasts.
Previously, the society recommended mammograms and clinical breast exams every year, starting at 40.
The changes reflect increasing evidence that mammography is imperfect, that it is less useful in younger women, and that it has serious drawbacks, like false-positive results that lead to additional testing, including biopsies.
But the organization's shift seems unlikely to settle the issue. Some other influential groups recommend earlier and more frequent screening than the cancer society now does, and some recommend less, leaving women and their doctors to sort through the conflicting messages and to figure out what makes the most sense for their circumstances.
The new guidelines were published Tuesday in the Journal of the American Medical Association.
The guidelines apply only to women at average risk for breast cancer — those with no personal history of the disease or known risk factors based on genetic mutations, family history or other medical problems.
"I think it has the potential to create a lot of confusion amongst women and primary care providers," said Dr. Therese B. Bevers, the medical director of the Cancer Prevention Center at the University of Texas M. D. Anderson Cancer Center in Houston.
The National Comprehensive Cancer Network, an alliance of prominent cancer centers, recommends mammograms every year starting at age 40. The American College of Obstetricians and Gynecologists recommends them every year or two from ages 40 to 49, and every year after that. It also recommends yearly clinical breast exams starting at age 19.