About half of all women 40 or older in the U.S. have dense breasts, a risk factor for breast cancer. But University of Iowa Health Care is beating the odds with a diagnostic tool that more efficiently identifies cancer in dense breast tissue.
Breast density measures the ratio of glandular tissue to fat in the breast. This can vary from entirely fatty to extremely dense. When patients have heterogeneously and extremely dense breast tissue, they are considered to have dense breasts, said Fabiana C. Policeni, MD, a radiologist and breast imaging director at University of Iowa (UI) Health Care, which is a member of the AMA Health System Program that provides enterprise solutions to equip leadership, physicians and care teams with resources to help drive the future of medicine.
Dense breasts make it more difficult for radiology to detect tumors, said Dr. Policeni.
That is why, in 2023, the breast imaging team at University of Iowa Health Care implemented an imaging modality called contrast-enhanced mammography. This form of mammography uses iodine-based contrast dye to detect neovascularization of cancer tumors in dense breasts. It’s also used in patients who have contraindication for or cannot tolerate breast magnetic resonance imaging (MRI).
It is an emerging modality and many other institutions in the United States are using contrast-enhanced mammography, said Dr. Policeni.
Catching what regular screenings miss
The process is very similar to a regular mammogram, said Dr. Policeni in an interview.
“We inject the contrast iodine IV, then we take the imaging,” she explained.
Combining this technology with digital breast tomosynthesis or 3D mammograms—another tool designed to identify tumors in dense breasts—would “better characterize a questionable abnormal finding and identify abnormal vascularly that could suggest a cancer and a biopsy would be recommended,” said Dr. Policeni.
UI Health Care only offers contrast-enhanced mammography to patients whose initial screening shows an abnormality. However, since the program launched last November, the imaging team has been able to find cancers that would have been missed with a regular mammogram.
Implementation was a team sport
All levels of the breast-imaging team had to make workflow adjustments to implement this new imaging modality.
This started with scheduling, said Dr. Policeni. Staff had to make sure they asked the right questions to ensure that patients would not have a contrast reaction. Testing for renal function in patients with diabetes or in older patients was another necessary step.
Staff also had to be trained on using an IV access for the contrast injection, and how to respond to a potential allergic reaction to the contrast.
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Awaiting further approvals from FDA
Although it’s been approved as a diagnostic tool, the Food and Drug Administration (FDA) has yet to approve contrast-enhanced mammography for screening purposes.
More than 15 prospective clinical trials are examining this option, said Dr. Policeni. One large study—the “Contrast-Enhanced Mammography Imaging Screening Trial”—is comparing contrast-enhanced mammography with 3D mammograms in patients who have dense breasts to see whether it could identify more cancer with fewer false positives.
Next steps are to work with the university to implement an abbreviated breast MRI—a supplemental screening tool for patients with dense breasts, said Dr. Policeni.
Abbreviated MRI is shorter, she explained, noting that “after the administration of contrast, we scan the patient only once,” compared with full protocol MRI, which scans the patient four times.
The plan is to provide this specific MRI protocol to patients with dense breasts who are not at high risk for breast cancer, since the full MRI protocol is reserved for high risk patients.
Use supplemental screening tools
Early detection of breast cancer improves outcomes and prognosis, said Dr. Policeni. This underscores the importance of routine screening mammograms.
When it comes to patients with dense breasts and cancer detection, physicians should keep in mind that mammograms aren’t as sensitive in detecting tumors in dense breasts, she added. In patients with entirely fatty breasts, mammogram sensitivity can be as high as 98%, compared with 30% in patients with dense breasts.
For this reason, physicians should be aware of supplemental diagnostic tools that can better assist patients with dense breasts, said Dr. Policeni.
The U.S. Preventive Services Task Force (USPSTF) has urgently called for more research on whether and how additional screening might help women with dense breasts find cancers earlier. There is not currently enough evidence for the USPSTF to recommend for or against additional screening, but women are encouraged to talk to their physicians about their options for follow-up testing so that they can get the care that’s right for them.
