Current Insights and Emerging Roles for Contrast-Enhanced Mammography

Sharing insights from the literature and her clinical experience with contrast-enhanced mammography (CEM), Jordana Phillips, M.D., reviewed current concepts and emerging roles for the use of CEM during a recent lecture presentation at the 2024 American Roentgen Ray Society (ARRS) Annual Meeting in Boston.

A 2020 meta-analysis revealed that CEM had comparable pooled sensitivity to MRI for the detection of primary breast cancer (97 percent for both modalities) but the meta-analysis authors also showed a 14 percent higher pooled specificity rate for CEM (66 percent vs. 52 percent), according to Dr. Philips, the section chief of breast imaging at the Beth Israel Deaconess Medical Center in Boston.

For the detection of additional malignant foci, Philips noted four different studies that consistently demonstrated lower false positive rates with CEM in comparison to MRI (with differences ranging between 10 to 77 percent).

“(Contrast-enhanced mammography) can be used as an alternative to MRI for breast cancer staging,” noted Dr. Phillips. “This is really important, especially for those practices that don’t have easy access to (MRI) where patients have to drive quite a long way to get their (MRI).”

Contrast-enhanced mammography also provides a viable option for the assessment of neoadjuvant chemotherapy (NAC) in patients with breast cancer. Dr. Phillips said the authors of another meta-analysis noted similar specificity of CEM and MRI (82 percent for both) and higher sensitivity for CEM (83 percent vs. 77 percent). Other research comparing digital mammography, CEM and MRI showed similar correlations between post-treatment tumor measurements and pathology, according to Dr. Phillips.

“The size difference between pathology and CEM is very similar to the size differences that we see with mammography and MRI,” maintained Dr. Phillips. “There is a variability in what we see with the data but they’re all really close to the size of the tumor, which is really the most important take-home message.”

Dr. Phillips also suggested that CEM may have utility in the downgrading of BI-RADS 4 lesions. In a 2020 study comparing digital mammography (DM)/digital breast tomosynthesis (DBT), ultrasound and CEM, Dr. Phillips pointed out that CEM had a significantly higher average true positive rate (90.3 percent) that was comparable to ultrasound (88.9 percent) and significantly higher than DM/DBT (73.6 percent). She noted the study also revealed a significantly lower average false positive rate for CEM (39 percent) in comparison to DM/DBT (47.3 percent) and ultrasound (60.8 percent).

For the assessment of architectural distortion on CEM, Dr. Phillips noted that one study found that 33 of 33 cancers were enhanced on CEM and another study revealed that 15 out 16 invasive breast cancers were enhanced on CEM.

“I love (CEM) for evaluating architectural distortion. I really would do it almost 100 percent of the time for recalls,” maintained Dr. Phillips. “I do it because when it’s a questionable distortion, I use it for triaging. I use it to help me understand whether to do something to move forward or not. When it’s a suspicious area of enhancement, I do it for staging.

Three Key Takeaways

Comparable sensitivity, higher specificity. Contrast-enhanced mammography (CEM) exhibits sensitivity comparable to MRI for primary breast cancer detection (97%), with the added advantage of a 14% higher specificity rate (66% vs. 52%) according to a 2020 meta-analysis.
Utility in neoadjuvant chemotherapy (NAC) assessment. CEM offers a valuable option for evaluating neoadjuvant chemotherapy (NAC) response in breast cancer patients. Meta-analyses indicate similar specificity but higher sensitivity for CEM compared to MRI (82% vs. 77%). Additionally, research shows comparable correlations between post-treatment tumor measurements and pathology for CEM, MRI, and digital mammography.
Enhanced detection and triage abilities. CEM demonstrates promise in downgrading BI-RADS 4 lesions and evaluating architectural distortion. Studies indicate CEM's significantly lower false positive rates in this patient population. CEM also shows effectiveness in detecting enhanced architectural distortions associated with breast cancer, aiding in more accurate triaging decisions during recalls.

Could CEM have an impact for women with intermediate breast cancer risk? While Dr. Phillips noted that CEM is not currently cleared by the FDA for screening of women at intermediate risk for breast cancer, studies suggest the benefit of CEM over mammography.

In three studies looking at the use of CEM in these patient populations, Dr. Phillips said CEM offered sensitivity that was 38.9 percent, 37.5 percent, and 38.5 percent higher than that of mammography. She also noted that CEM offered additional cancer detection rates of +9/1000, +6.5/1000, and +13/1000 in comparison to mammography in these studies.

“We find that the sensitivity of mammography is much lower than the sensitivity of (CEM),” emphasized Dr. Phillips. “We are finding more cancers with (CEM) than what are seeing with mammography alone.”

Dr. Phillips added that multicenter prospective research (the Contrast Enhanced Mammography Imaging Screening Trial (CMIST)) is underway to compare CEM and DBT in women with dense breasts who have average to intermediate risk for breast cancer.