Women who receive at least three screening mammograms have a 49 percent lower risk of dying from breast cancer, according to a new study. Researchers identified 755 patients who died from breast cancer between 1995 and 2003 and matched them with 3,739 controls. They found that if women had at least three screenings prior to diagnosis, their risk for mortality from breast cancer was reduced by 49 percent. The greatest reduction was seen in women between 70 and 75 years old, for whom the reduction in mortality was 84 percent. Among younger women (ages 50 to 69 years), the reduction was smaller, at 39 percent. Among the breast cancer cases, 29.8 percent were detected at screening, 34.3 percent were detected between screenings, and 35.9 percent of cases had never been screened. Also, fewer women who participated in screening had advanced cancers. Stage IV tumors were present in 29.5 percent of the never-screened cases but in only 5.3 percent of the screen-detected cases; stage IV tumors were found in 15.1 percent of the interval-detected cases.
From “Mammography Screening and Risk of Breast Cancer Death: A Population-Based Case–Control Study”
Cancer Epidemiology, Biomarkers & Prevention (12/06/11) Otto, Suzie J. ; Fracheboud, Jacques; Verbeek, André L. M.; et al.