New research suggests that employing contrast-enhanced mammography (CEM) after digital breast tomosynthesis (DBT) may enhance the detection of early breast cancer.
For the prospective study, recently published in Radiology, researchers reviewed data for 601 women (mean age of 56) who had single screening CEM in addition to DBT. All women in the cohort were eligible for supplemental magnetic resonance screening (MRI). Over 78 percent of the cohort had heterogeneously dense breasts and 8.5 percent had extremely dense breasts, according to the study. The study authors noted that postmenopausal women comprised 66.6 percent of the study group.
The researchers detected a total of 16 malignant lesions in 12 women. While CEM and DBT detected breast cancer in six of the women, the study authors noted that breast cancer in the remaining six women was only detected with CEM. The study authors pointed out that five of those women had node-negative invasive disease with an 0.7 cm median lesion size, and there were three cases of lobular breast cancer.
For one reviewing radiologist, the addition of CME to DBT led to an 18.3 cancer yield per 1,000 women vs. 8.3 per 1,000 women for DBT alone, according to the researchers. They also noted a 19 percent increase in the AUC for breast cancer detection for the combination of CME and DBT in contrast to DBT alone (92 percent vs. 73 percent).
“ … Our results show great promise for screening contrast-enhanced mammography as an alternative to MRI. The ongoing Contrast-Enhanced Mammography Imaging Screening Trial will further address the role, if any, of concurrent digital breast tomosynthesis (DBT), although we found no cancer detection benefit to concurrent DBT in this series,” wrote lead study author Wendie Berg, M.D., Ph.D., a professor of radiology at the University of Pittsburgh School of Medicine, and colleagues.
Three Key Takeaways
1. Enhanced cancer detection. Adding CEM to DBT nearly doubled the cancer detection yield (18.3 vs. 8.3 per 1,000 women) and improved diagnostic performance with a 19% increase in AUC (92% vs. 73%) compared to DBT alone.
2. Early and node-negative detection. CEM alone identified cancers missed by DBT in half of the diagnosed women, including small (median 0.7 cm), node-negative, and lobular carcinomas — highlighting its value in early-stage cancer detection.
3. Increased false positives with potential decline over time. While CEM+DBT increased the false-positive rate by 13.5 percent in comparison to DBT only, the authors anticipate this rate may decline with ongoing incidence screening.
The study authors noted a 13.5 percent increase in the false-positive rate (FPR) for the combination of CEM and DBT in comparison to DBT alone (21.6 percent vs. 8.1 percent). However, the researchers noted key characteristics in the cohort that may have contributed to the reported FPR.
“Compared with our population of women with (a past history of breast cancer), women in the present Screening Contrast-enhanced Mammography as an Alternative to MRI, or SCEMAM, study are younger, were more likely to have dense breasts, and had no previous radiation therapy or endocrine therapy. These factors all influence background parenchymal enhancement at CEM,” pointed out Berg and colleagues. “ … The relatively high FPR we observed from the addition of CEM to DBT is expected to decrease with incidence screening, as was observed in the Dense Tissue and Early Breast Neoplasm Screening trial with screening MRI and as reported in several studies of screening CEM.”
(Editor’s note: For related content, see “Contrast-Enhanced Mammography and High-Concentration ICM Dosing: What a New Study Reveals,” “Abbreviated MRI and Contrast-Enhanced Mammography Provide Fourfold Higher Cancer Detection than Breast Ultrasound” and “Contrast-Enhanced Mammography Study Reveals 24 Percent Lower Sensitivity with Moderate/Marked BPE.”)
In regard to study limitations, the authors acknowledged that the lack of prospective documentation for low-energy findings that were different from the synthetic two-dimensional mammography findings thwarted assessment of specificity and standalone recall rates for CEM. They also conceded one prevalent screening session for participants in this pilot study.
