Study Shows Tomosynthesis Detects More Breast Cancers Than Traditional Mammography
One-view digital breast tomosynthesis detects 40% more breast cancers than two-view digital mammography does, according to a major screening study from Lund University in Sweden. The study’s results were published by Lång et al in European Radiology.
This is the first large-scale study to compare tomosynthesis with regular mammograms. Breast compression is halved in tomosynthesis, making the technique more comfortable for women than mammography.
“We see a change as inevitable. Breast tomosynthesis will be introduced; it is just a question of when and on what scale,” explained Sophia Zackrisson, MD, PhD, and Kristina Lång, MD, radiologists at Skåne University Hospital and researchers at Lund University.
Breast Tomosynthesis
Breast tomosynthesis is a three-dimensional x-ray technique that makes it easier to detect tumors in breast tissue. The technique works on the same principle as tomography, meaning that x-ray images of the breast are acquired from different angles, which can then show multiple thin layers of the breast. This is compared with a traditional mammography, where all the breast tissue is reproduced in a single image, which can hinder the early detection of tumors.
The new technique also reduces discomfort and pain, because the breast does not have to be compressed as firmly as in the current examination technique. This could lead to higher levels of participation in future screening programs.
Among the other advantages are lower radiation doses than in traditional mammography, and the ready availability of the equipment on the market, which would facilitate a transition.
Study Findings
A total of 7,500 women aged 40 to 74 took part in the first half of the study, which formed the basis for the findings. Breast cancer was found in 68 of these women; of them, 48 cases of breast cancer were detected by both screening methods, 21 were detected by tomosynthesis alone, and 1 was detected by mammography alone.
The detection rate for tomosynthesis was 8.9/1,000 screens, a significant improvement over the rate of 6.3/1,000 screens that mammography screening achieved (P < .0001).
Possibility of Overdiagnosis
However, there are a few challenges remaining before the method can be introduced on a large scale. As with other screening methods, there is a risk of overdiagnosis (in mammography screening, the figure is 10% to 20%). Further studies are needed to investigate the rate of overdiagnosis with tomosynthesis, but the study found that there was an increase in recall rates (3.8% for tomosynthesis vs 2.6% for mammography, P < .0001). This is a drawback in screening, said Dr. Lång, as it can cause unnecessary psychological stress. The ongoing research will also look at costs, as breast tomosynthesis is a somewhat more expensive technique.
“We see 5 to 10 years from now as a possible timeframe for the large-scale introduction of the technique. There is also an aspiration for more personalized screening, and breast tomosynthesis could therefore be one of several methods used,” concluded Dr. Zackrisson.
Dr. Lång is the corresponding author of the European Radiology article.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
