3D Mammography finds significantly more invasive cancers and reduces unnecessary recalls, according to a large, retrospective study published in the June 25 issue of the JAMA (Friedewald et al Breast Cancer Screening Using Tomosynthesis in Combination With Digital Mammography. JAMA. 2014;311(24):2499) The study, the largest of its kind, focused on the impact of 3D mammography at a diverse range of sites across the U.S, looking at nearly half a million mammograms at 13 sites. Key findings were a 41% increase in invasive cancer detected with 3D mammography; a 15% decrease in unnecessary recalls for false positives; and a 29% increase in the detection of all breast cancers.
“This study confirms what we already know: 3D mammography finds more of the invasive, harmful cancers we want to find and saves women the anxiety and cost of having additional exams for what turns out to be a false alarm,” said the study’s co-author Donna Plecha, MD. “We already knew that breast screening saves lives and this study provides us with firm data that 3D mammography is a better test for detecting breast cancer early when it is treatable.” Hologic’s 3D mammography (breast tomosynthesis) system was used exclusively in the study, as this is the only FDA-approved 3D mammography. The system combines advanced digital mammography and tomosynthesis-generated images to provide a more detailed, highly focused picture of the breast. These images are then used to produce a series of one-millimeter thick slices that can be viewed as a 3D reconstruction of the breast. Women see little difference between a conventional 2D mammogram and a 3D mammogram. The exam takes just a few seconds longer and the positioning is the same. The technology gives radiologists the ability to identify and characterize individual breast structures and clearly see features which might be obscured in a traditional 2D mammogram by overlapping normal breast anatomy that may mimic or mask a tumor. Dense tissue and overlapping tissue structures may lead to false positive or false negative results with standard mammography.
Breast cancer remains a significant health problem and statistics indicate that one in eight women will develop the disease in her lifetime. The stage at which the cancer is discovered influences a woman’s chance of survival and annual mammography after the age of 40 enables physicians to identify even the smallest abnormalities. In fact, when breast cancer is detected early and confined to the breast, the five-year survival rate is 97 percent. “Breast cancers caught in the initial stages by mammography are more likely to be cured and are less likely to require chemotherapy or as extensive surgery,” said Dr. Plecha. “This study shows that 3D mammography is a more effective screening tool, and we must make it accessible to all women.”