Breast MRIs are on the rise—but not among women who need them most

Communities are failing to follow guidelines that ensure women at an increased risk for breast cancer receive additional MRI screening, according to research from the University of New Mexico’s School of Medicine.

While mammography remains the gold standard for annual breast exams, U.S. guidelines issued in 2007 triggered a rise in using MR imaging for cancer detection as well, Deirdre A. Hill, MPH, and colleagues wrote in the Journal of General Internal Medicine.  Since then, the American Cancer Society, American College of Radiology and the Society for Breast Imaging have all backed guidelines urging women with a more than 20 percent lifetime risk for breast cancer to undergo supplemental MRI in addition to a mammogram.

Hill and co-authors analyzed data for 348,955 women from the Breast Cancer Surveillance Consortium, which collects information about risk factors, imaging, cancer diagnoses and the pathologies of women who are screened. Of the hundreds of thousands in five regional BCSC registries, 1,499 underwent an additional MRI.

Though previous studies have proven that an extra MRI leads to better detection rates, Hill’s team found the majority of women who opt for an additional screening—82.9 percent—didn’t meet professional recommendations. Of those women, 35.5 percent were either at a low or average risk for breast cancer.

“Our data suggest that women with less than 20 percent lifetime risk based on family history, but who have high breast density, breast atypia or abnormal cell growth called lobular carcinoma in situ undergo MRI at many times the rate of other women, although the harms and benefits in this population are uncertain and the cost-benefit ratio may exceed established benchmarks,” Hill said in a release from Springer. “Such women may not be at substantially increased risk of cancers missed by mammography and thus may not be the groups in greatest need or who would receive the greatest potential benefit of screening MRI.”