The mammogram debate was reignited this week with two new studies suggesting that routine breast cancer screening may benefit women in their 40s if they have certain risk factors.
In 2009, the U.S. Preventive Services Task Force (USPSTF) rolled back longstanding recommendations for routine mammography, advising against it for women in their 40s; the revised guidelines recommend that women get mammograms every other year starting at age 50 instead.
The USPSTF’s controversial advice was based on data suggesting that routine mammography did more harm than good for women in their 40s. Although there’s no question that early detection of cancer can save lives, the task force reasoned that breast cancer risk is not high enough in 40-somethings to justify the potential risks of screening: false positive results, overdiagnosis and unnecessary biopsies and treatment. Mammography also picks up tiny tumors that may not have caused any symptoms during a woman’s lifetime, but are still treated with surgery, radiation or chemo unnecessarily.
Not every cancer group agrees with the USPSTF’s advice. The American Cancer Society still recommends more frequent screening, advising women over age 40 to get a mammogram every year.
The two new reports, published Monday in the Annals of Internal Medicine, suggest that yearly mammograms may benefit women in their 40s with certain risk factors — those who have very dense breasts and those with a close family relative like a sister, mother or daughter who had breast cancer.
In one study, led by Dr. Heidi Nelson of Oregon Health & Science University in Portland, researchers reviewed 66 studies to determine what factors increase women’s chances of getting breast cancer. After looking at family history, weight, drinking and smoking habits and whether the women had ever given birth or breast-fed, the team concluded that: “Extremely dense breasts and first-degree relatives with breast cancer were each associated with at least a twofold increase in risk for breast cancer in women aged 40 to 49 years.”
The other paper, a comparative modeling study led by Nicolien van Ravesteyn from Erasmus Medical Center in Rotterdam, the Netherlands, looked at the pros and cons of breast cancer screening among different groups of women and found that those in their 40s who had a twofold increased breast cancer risk due to family history or breast density benefited as much from biennial screening as average-risk women aged 50 to 74.
Nelson and van Ravesteyn, along with other researchers, worked on both studies.
“If you’re a 40-year-old who’s at high risk of breast cancer, then undergoing mammography every two years makes sense for that person. If you’re a 40-year-old person who’s at very low risk, waiting ’til you’re 50 is reasonable,” researcher Dr. Karla Kerlikowske of the University of California, San Francisco, who also worked on the studies, told NPR.
But other health experts were wary about the findings. “This may discourage women who don’t have an identifiable risk factor from seeking screening, and therefore the potential lifesaving benefit of screening won’t be realized,” Dr. Carol Lee of the American College of Radiology told NPR.
Dr. Otis Brawley, chief medical officer of the American Cancer Society, said that his group would not change its recommendations based on the new studies, but acknowledged that using such data to profile women who are most at risk could potentially be helpful. In an accompanying editorial, Brawley said, “risk-based screening can refocus efforts onto the women who are most likely to benefit from screening,” but he concluded that ultimately screening will depend on the preferences of individual women.