For young women with BRCA1/2 mutations or who are otherwise at high risk for breast cancer, the current American Cancer Society guidelines recommend the inclusion of screening MRI, which has been shown in several studies to have increased sensitivity (79.5% to 91%) for T2 or smaller breast cancer compared to mammography with or without the addition of ultrasound (33% to 50%) [46–49]. This evidence concerns the gene BRCA1 and cancer.