Additional MR screening helps identify previously undiagnosed breast cancers in women with average lifetime risk.
Among women with average breast cancer risk, supplemental breast MR imaging can improve early diagnosis of relevant breast cancers. In a prospective, observational study conducted in two academic breast centers in Germany, published in Radiology, researchers examined women, ages 40-to-70, without breast cancer-associated risk factors. Their life time risk was <15 percent. Between January 2005 and December 2013, women with at least minimal residual breast tissue (ACR categories A-D) and normal imaging findings (screening mammography with or without screen ultrasonography) underwent supplemental MR screening. Outcomes measures were supplemental cancer detection rates, interval cancer rates, and biologic profiles of MR image-detected additional cancers, and specificity and positive predictive value of MR image screening. A total of 2,120 women underwent MR screening. Breast MR depicted 60 additional breast cancers (ductal carcinoma in situ, n=20, invasive carcinoma, n=40). The overall supplemental cancer detection rate was 15.5 per 1,000 cases. MR imaging at initial screening detected 48 additional cancers. During 1,741 subsequent screening rounds, 12 of 13 incident cancers were found with MR imaging alone.MR-diagnosed cancers were small (median 8mm), node negative in 93.4 percent of cases, and de-differentiated (high-grade cancer in 41.7 percent at prevalence screening, and 46.0 percent at incidence screening. Researchers concluded women at average breast cancer risk could see improvement in early diagnosis through supplemental MR screening.