Breast MRI more accurate than mammography in diagnosing invasive cancer in high-risk women

A study by Sung et al published in Radiology found that breast MRI screening is more likely to detect invasive cancers than mammography in women at higher risk. 

The study was a retrospective review of 7,519 high-risk women due to family or personal history of breast cancer, high risk lesion, BRCA mutation status or radiation to the chest, who underwent MRI screening and mammography.

A total of 18 064 screening MR imaging examinations and 26 866 screening mammographic examinations were performed. Two hundred twenty-two cancers were diagnosed in 219 women, 167 (75%) at MR imaging, 43 (19%) at mammography, and 12 (5%) interval cancers. Median age at diagnosis was 52 years.  Cancers found at screening MR imaging were more likely to be invasive cancer 118 of 167 or 71%. Of the 43 cancers found at screening mammography, 38 (88%) manifested as calcifications and 28 (65%) were ductal carcinoma in situ. Interval cancers were associated with nodal involvement were of the triple-negative subtype.

In conclusion MRI of the breast was better than mammography in detecting invasive breast cancer in women at high risk for breast cancer.  Mammography had an advantage for the detection of calcifications and thus for ductal carcinoma in situ.