BACKGROUND: Breast magnetic resonance imaging (MRI) with conventional screening methods improves sensitivity in high-risk patients without benefits on specific survival. We evaluated the characteristics, treatments, and prognostic features of breast cancers diagnosed among BRCA1/2 mutation carriers either inside or outside screening programs that included MRI. PATIENTS AND METHODS: Two groups of patients diagnosed with a new breast cancer between 2001 and 2007 were compared: group 1, patients included in an intensive screening program; and group 2, patients outside of this program. RESULTS: Twenty-one patients met inclusion criteria for group 1, and 102 for group 2. Seventy-four percent and 65%, respectively, were BRCA1 mutation carriers. Tumors in both groups had the same characteristics (pN, grade, estrogen receptor, progesterone receptor, HER2 expression), except for smaller tumor size in group 1 (median, 6 mm vs. 22 mm; P < .0001). Group 1 patients had more frequent sentinel node procedures (57% vs. 28%; P = .021) and less commonly received chemotherapy (43% vs. 86%; P < .0001). The 3-year disease-free survival (93% vs. 74%; P = .1) and the 3-year overall survival (100% vs. 92%; P = .2) did not differ between groups. CONCLUSION: MRI might provide improvement in BRCA1/2 carriers in terms of smaller tumor size and treatment morbidity. However, because of aggressive intrinsic characteristics, this does not turn into significant survival benefits.