May 1, 2012
Risk Factors May Inform Breast Cancer Screening
Mammograms might benefit women in their 40s with family history or dense breasts
Choosing when to start regular breast cancer screening is a complicated decision for individual women and their providers. For most women, increasing age is the biggest risk factor for breast cancer, which is much more common at age 60 than at 40. But two new articles on other risk factors may inform guidelines and clinical practice about screening mammography from age 40 to 49.
The articles in the May 1 Annals of Internal Medicine provide information on how certain risk factors affect breast cancer risk and shift the balance between harms and benefits. Screening harms include false-positive results that can lead to invasive follow-up procedures and overdiagnosis, which prompts unnecessary treatment. Screening has a less favorable balance between benefits and harms in average-risk women in their 40s than in women aged 50 to 74.
This research addresses the need for more information about screening women in their 40s–a need that the U.S. Preventive Services Task Force highlighted in its 2009 updated breast cancer screening guidelines. Also published in the Annals of Internal Medicine, these guidelines advise screening mammography every two years for women aged 50 to 74. The guidelines recommend that women in their 40s consider their personal values regarding the benefits and harms and then decide when to begin regular screening.
Group Health Research Institute Senior Investigators Diana Miglioretti, PhD, and Diana Buist, PhD, contributed to both of the new Annals articles. Together, the companion articles estimate that the benefits and harms of getting screening mammograms every two years are the same for groups of women aged 40-49 who have a twofold increased risk level of breast cancer as for groups of women aged 50