Women with dense breast tissue could benefit from an advanced cancer screening procedure called molecular breast imaging (MBI), according to a new study published Sept. 23 in Radiology. When paired with 3D mammography, MBI more than doubled the detection of advanced breast cancers.
“MBI detected an additional 6.7 cancers per 1,000 screenings at year one and an additional 3.5 cancers per 1,000 screenings at year two,” said lead researcher Carrie Hruska, professor of medical physics at the Mayo Clinic. Importantly, 70% of cancers found only by MBI were invasive.
How Molecular Breast Imaging Works
MBI involves injecting a radioactive tracer dye into the body. The tracer highlights fast-growing cancer cells in breast tissue, making them visible with specialized imaging equipment.
For the study, researchers combined MBI with 3D mammography (also called digital breast tomosynthesis, or DBT), which uses multiple X-rays from different angles to create a 3D image of the breast.
Study Design and Results
Nearly 3,000 women with dense breasts, average age 57, were enrolled between 2017 and 2022. About 80% had no family history of breast cancer. Participants underwent two years of annual screening with MBI plus DBT.
Key findings:
- 30 cancers in 29 women were detected by MBI alone and missed by DBT.
- 71% of those cancers were invasive.
- Adding MBI to DBT increased invasive breast cancer detection 2.5-fold.
“Someone who’s having their routine annual screen every year should not be diagnosed with advanced breast cancer,” Hruska emphasized.
Safety and Accessibility
Researchers noted that MBI is safe, well-tolerated, and relatively inexpensive. The radiotracer used in MBI has a long history in cardiac imaging, with fewer risks and no contrast reactions compared to other modalities.
Implications for Women With Dense Breasts
About 47% of women undergoing breast screening have dense breasts, which makes it harder for mammograms alone to detect cancer. The study highlights the importance of supplemental screening for this group.
“I don’t want to discourage anyone from getting a mammogram, because they absolutely should,” Hruska said. “However, DBT doesn’t find all cancers, and women need to understand its limitations and consider how supplemental screening can fill the gap.”
She added that women should be involved in decision-making and understand the pros and cons of different screening methods.
