Patients with and without a personal history of breast cancer (PHBC) have higher biopsy rates and lower cancer yields following biopsy in the 90 days after screening MRI than in the 90 days after a traditional mammogram, according to a new study published in JAMA Internal Medicine.

The authors looked at data from six different Breast Cancer Surveillance Consortium registries from 2003 to 2013. Overall, the surgical biopsy rate per 1,000 screening episodes increased from 23.6 after mammography to 57.1 after breast MRI in women with PHBC. The surgical biopsy rate per 1,000 screening episodes jumped from 14.9 after mammography to 84.7 after breast MRI in women without PHBC. In addition, mammography was associated with a higher yield of ductal carcinoma in situ and invasive breast cancer.

“Our findings support the need to define and identify the appropriate selection of women for MRI screening to minimize the harms in low-risk women,” wrote lead author Diana S.M. Buist, PhD, MPH, with  the Kaiser Permanente Washington Health Research Institute, and colleagues. “Better understanding clinical pathway patterns of multimodality screening and their associated outcomes could help to simultaneously improve the patient care experience and the health of populations while reducing per capita costs for achieving high-quality outcomes for high-risk populations and among the growing population of women with a PHBC.”

Buist et al. noted that their findings can’t necessarily be compared to other studies that consider 12 months’ follow-up for cancer outcomes; this specific study focused on biopsies within 90 days of screening. The authors also emphasized that breast MRI is only recommended for high-risk patients. “The use of MRI may facilitate identifying high-risk women eligible for genetic counseling and/or primary prevention by identifying high-risk benign lesions that would increase 5-year risk to greater than 3 percent ,but guidelines have not been established to support this practice,” they wrote.