New research suggests contrast-enhanced mammography (CEM) provides a significantly higher sensitivity rate and a lower specificity rate than low-energy mammography (or two-dimensional full-field mammography) for detecting breast cancer in women with extremely dense breasts.
For the retrospective study, recently published in Radiology, researchers reviewed 1,264 screening CEM exams performed for a total of 609 patients with extremely dense breasts (mean age of 49.8), and compared CEM vs. low-energy mammography. The low-energy mammography views were obtained from CEM and were deemed to be equivalent to two-dimensional full-field digital mammography, according to the study authors. The researchers noted 18 cases of diagnosed breast cancer, including 16 cases involving screen-detected cancers and two cases of interval breast cancer.
The researchers found that CEM diagnosed 16 of the 18 breast cancer cases for a sensitivity rate of 88.9 percent in comparison to 27.8 percent for low-energy mammography, which diagnosed five out of 18 breast cancer cases.1
The study authors maintained that the sensitivity findings with CEM mirrored reported breast magnetic resonance imaging (MRI) sensitivity rates reported in the 2019 DENSE trial.2
“This finding highlights the additive diagnostic value of contrast-enhanced over anatomic imaging among women with extremely dense breasts. … In accordance with the DENSE trial, most of the cancers screen-detected with CEM were T-stage 1, node-negative, invasive carcinomas, thus demonstrating the potential for early detection of possibly aggressive breast cancer,” noted lead author Noam Nissan, M.D., Ph.D., who is affiliated with the Department of Radiology at Memorial Sloan Kettering Cancer Center in New York, N.Y., and colleagues.
Low-energy mammography imaging did have a higher specificity rate in comparison to CEM (96.2 percent vs. 88.9 percent), but the researchers also noted improved CEM specificity for follow-up examinations (90.7 percent vs. 85.9 percent at baseline).1
“This could be attributed to the availability of previous images at follow-up rounds of imaging, which facilitates the comparison of contrast enhancement and therefore allows for the consideration of enhancement as unchanged, and therefore benign,” added Nissan and colleagues. “Furthermore, as clinical experience with CEM increases, it may be possible to avoid additional evaluation and/or biopsies for non-enhancing masses and asymmetries.”
Three Key Takeaways
1. Higher sensitivity of contrast-enhanced mammography (CEM). CEM demonstrated a significantly higher sensitivity rate (88.9 percent) for detecting breast cancer compared to low-energy mammography (27.8 percent), making it more effective for early detection in women with dense breasts.
2. Specificity differences. While low-energy mammography had a higher specificity (96.2 percent vs. 88.9 percent), CEM showed improved specificity for follow-up exams (90.7 percent), indicating its growing diagnostic reliability as more data from previous images becomes available and there is more increased experience with the modality.
3. Potential screening protocol shift. CEM may soon be incorporated into breast cancer screening protocols for women with dense breasts, as it is seen as a superior alternative to conventional mammography, with growing clinical support for its implementation.
In an accompanying editorial, Marc B.I. Lobbes, M.D., Ph.D., called for large prospective trials to build upon the demonstrated research for CEM.3 However, he also maintained that CEM is a safe, superior option to conventional mammography for women with dense breasts and suggested it is only a matter of time before CEM is incorporated into breast cancer screening protocols.
“The implementation of screening CEM no longer seems to be a question of yes or no, but more of when and in what specific populations,” posited Dr. Lobbes, a radiologist in the Department of Medical Imaging at the Zuyderland Medical Center in Geleen, the Netherlands.
(Editor’s note: For related content, see “Current Insights and Emerging Roles for Contrast-Enhanced Mammography,” “Contrast-Enhanced Mammography and Dense Breasts: What a New Meta-Analysis Reveals” and “Study Says Contrast-Enhanced Mammography Offers Comparable Breast Cancer Detection to MRI.”)
Beyond the inherent limitations of a single-center retrospective study, the authors acknowledged subjective determination of breast density and the inclusion of women who had other risk factors beyond having extremely dense breasts.
References
1. Nissan N, Comstock CE, Sevilimedu V, et al. Diagnostic accuracy of screening contrast-enhanced mammography for women with extremely dense breasts at increased risk of breast cancer. Radiology. 2024 Oct;313(1):e232580. doi: 10.1148/radiol.232580.
2. Bakker ME, de Lange SV, Pijnappel RM, et al. Supplemental MRI screening for women with extremely dense breast tissue. N Engl J Med. 2019;381(22):2091-2102.
3. Lobbes MBI. A decade of contrast-enhanced mammography: expanding screening to women at intermediate or high risk for breast cancer. Radiology. 2024 Oct;313(1):e241970. doi: 10:1148/radiol.241970.
