3D Mammography Detects More Breast Cancers, Reduces Advanced Cases

A new 10-year study has found that digital breast tomosynthesis (DBT), an advanced form of mammography, improves breast cancer detection rates and reduces the occurrence of advanced cancers compared to traditional 2D digital mammography. The results of the study, conducted by researchers at Yale University and published in Radiology, show the benefits of using DBT over standard mammography for breast cancer screening.

Conventional mammography, which takes two-dimensional X-ray images of the breast, has long been the primary tool for screening, but it has limitations. It fails to detect around 20% of breast cancers and often results in false positives, where non-cancerous abnormalities prompt additional tests. DBT, on the other hand, takes multiple images from different angles, reconstructing them into three-dimensional views that provide a clearer picture of the breast tissue.

In this retrospective analysis, researchers reviewed over a decade of screening data at Yale University/Yale-New Haven Health, which included 272,938 mammograms performed between 2008 and 2021. Of these, 35,544 were conducted with digital mammography, and 237,394 were done using DBT after the institution transitioned to the newer technology in 2011. The study identified 1,407 cancer cases, with the vast majority—1,265—detected by DBT, while 142 were found using digital mammography.

One of the key debates surrounding breast cancer screening is overdiagnosis—the detection of cancers that would not have become clinically significant if left undetected. Critics argue that the use of advanced screening technologies like DBT could lead to more overdiagnosis. However, the study found no significant difference between the two screening methods in detecting invasive cancers versus non-invasive ones, suggesting that DBT is not contributing to overdiagnosis.

Importantly, DBT was more effective at finding aggressive cancers at an earlier stage. The study showed that DBT detected cancers at a rate of 5.3%, compared to 4.0% for digital mammography, and identified fewer advanced cancers (32.7% versus 43.6%). This suggests that DBT catches cancers earlier, when they are more treatable. Additionally, the detection of cancer improved when women had regular screenings with DBT.

The study also highlighted a lower recall rate with DBT—7.2% compared to 10.6% for digital mammography—indicating that fewer women had to undergo unnecessary follow-up tests due to suspicious findings that turned out to be benign.

The results underscore the advantages of DBT, particularly its ability to detect cancer earlier and reduce the need for repeat screenings. The study adds to the growing body of research supporting DBT's role in breast cancer screening and may encourage more healthcare providers to adopt the technology as a standard practice.

Researchers emphasized the need for further studies to explore long-term outcomes of using DBT in screening programs and its potential impact on overall cancer survival rates. These findings could influence institutions that have yet to transition from traditional digital mammography to DBT, providing them with valuable evidence on the benefits of this newer screening method.