Ductal Carcinoma In Situ (DCIS) Diagnosed by MRI-Guided Biopsy among Mutation Carriers.

Background: While pathogenic sequence variants (PSVs) clearly confer an increased risk for invasive breast cancer, the extent to which these mutant alleles increase DCIS risk is less clear.

Objective: To assess the rate of detection over a 5-year period, and MRI imaging features of pure noncalcified DCIS in a cohort of Israeli PSV carriers attending a high-risk clinic from 2015 to 2020.

Materials And Methods: All female PSV-carriers followed at the Meirav High-risk clinic from 2015 to 2020 were eligible if they underwent semiannual breast imaging (MRI/mammography) and MRI-guided biopsy-proven pure DCIS. Clinical data, pathology information, and imaging characteristics were retrieved from the computerized archiving system.

Results: 18/121 (15.2%) participating PSV carriers and 8/81 (10.1%) PSV-carriers who underwent MRI-guided biopsy were diagnosed with DCIS. The median age of carriers and carriers was 49.8 years and 60.6 years, respectively ( = 0.55). Negative estrogen-receptor tumors were diagnosed in 13/18 (72%) and 2/8 (25%) PSV carriers ( < 0.05). Thirteen (13/18-72%) carriers had intermediate to high-grade or high-grade DCIS compared with 4/8 (50%) of carriers ( = 0.03). Over the 5-year study period, 29/1100 (2.6%) PSV carriers were diagnosed with DCIS seen on MRI only.

Conclusion: MRI-detected noncalcified DCIS is more frequent in PSV carriers compared with carriers, unlike the predominance in mammography-detected calcified DCIS. -related DCIS is diagnosed earlier, more likely to be estrogen receptor-negative and of higher grade compared with -related DCIS. Future prospective studies should validate these results and assess the actual impact they might have on clinical management of PSV carriers.