Studies Point to Reasons for Mammograms in 40s
Women With Dense Breasts or a Family History of Breast Cancer May Want to Consider Screening in Their 40s
Refining Recommendations on Mammograms
In 2009, the U.S. Preventive Services Task Force (USPSTF) said that most women should get routine mammograms every two years starting at age 50 instead of age 40.
That recommendation conflicts with guidelines from the American Cancer Society, the National Cancer Institute, and the American College of Radiology, which all recommend screening starting at age 40. And it has drawn mixed reactions from patients and doctors.
Some groups applauded the conservative approach, saying that it would reduce the harms of over-testing and overtreatment, which are greatest for women in their 40s.
Others said it would unnecessarily put women's lives at risk, since cancers found in younger women can be aggressive and early detection of an aggressive cancer may be a woman's best hope for survival.
Ultimately, the USPSTF said the decision to start breast cancer screening before age 50 should be left up to individual women and their doctors.
But until now, there's been little information to help guide that decision.
Family History or Dense Breast Tissue Doubles Risk
The new studies, which were conducted by the same group of researchers that compiled the evidence for the 2009 USPSTF recommendations, are meant to help clarify when mammograms might be useful for younger women.
The first study used four different models to simulate the benefits and harms of screening mammography in women ages 40 to 49.
That study found that women in their 40s need to have double the average risk of getting breast cancer to get the same degree of benefit from regular mammograms, meaning every other year, as women in their 50s.
"Between 40 to 49, the chance of developing breast cancer is under 2%, so even when you double that, it's still low," says researcher Jeanne S. Mandelblatt, MD, MPH, associate director for population sciences at Georgetown University Medical Center's Lombardi Comprehensive Cancer Center in Washington, D.C.
In a companion study, researchers asked what risk factors might actually double a woman's risk for breast cancer in her 40s.
For that study, researchers reanalyzed data from 66 published studies and included data on more than 380,000 women who are being tracked through the Breast Cancer Surveillance Consortium, a network of seven mammography registries.