Short-term follow-up of contrast-enhanced mammography lesions after negative breast MRI in women with elevated breast cancer risk

Purpose: To determine the outcome of enhancing lesions detected on contrast-enhanced mammography (CEM) that had no correlate on magnetic resonance imaging (MRI) and underwent short-term follow-up CEM.Methods: In this retrospective single-center study, we identified patients with elevated breast cancer risk who had a CEM between 2014 and 2021 showing indeterminate enhancement on recombined images (BI-RADS 0, 3, 4) that had no correlate on subsequent MRI (performed within one month), and therefore underwent short-term follow-up CEM (performed within eight months). Medical records and imaging studies were reviewed to collect data on patient and lesion characteristics, and outcomes. Cancer incidence with 95% confidence interval (CI) was calculated.Results: This study included 71 women (median age 49 years) with 81 enhancing CEM lesions who underwent short-term follow-up CEM (median 6.2 months) after MRI reported no correlate. Of 81 lesions (median size = 0.7 cm), 73 (90%) were non-mass enhancement and 8 (10%) were enhancing masses. No sonographic correlate was identified for 75 lesions that had a same-day targeted ultrasound. Two cancers (2.5%, 95% CI 0.3-8.6) were diagnosed during the short-term follow-up period, one at 6-months (invasive ductal carcinoma) and one at 12months (ductal carcinoma in situ). The remaining 79 lesions were benign at 6-month follow-up CEM and at oneyear mammographic follow-up.Conclusions: Follow-up CEM of MRI-occult lesions is prudent and may be reasonable to perform at one-year given the low incidence of cancer detected at six-months (one of 81) in our small study sample.

Automated summary

The study involved 71 women with 81 enhancing CEM lesions who underwent short-term follow-up CEM after MRI reported no correlate. Among the lesions, two cancers were diagnosed during the short-term follow-up period, while the remaining 79 lesions were found to be benign at follow-up. This suggests that follow-up CEM of MRI-occult lesions may be prudent, with a low incidence of cancer detected in a small sample size.