Utilization of breast cancer screening with magnetic resonance imaging in a community practice

Authors: Hill DA, Haas JS, et. al.

Source: J Gen Intern Med DOI: 10.1007/s11606-017-4224-6

www.ncbi.nlm.nih.gov/pubmed/29214373

Breast MRI is recommended for additional breast cancer screening among women with lifetime risks of breast cancer of 20% or greater. The modality has been shown to detect breast cancer at earlier stages compared to mammography alone in this population.  Breast cancer risk is calculated by several established risk calculators that include factors such as family history of the disease. The Gail model is one of these calculators that is widely used by physicians. Additionally, when a woman has at least two first-degree relatives with breast cancer, it is expected that her personal lifetime breast cancer risk will be at least 20%.

The authors of this study examined the use of breast MRI for breast cancer screening among over 348,000 women who were part of the Breast Cancer Surveillance Consortium. From 2007-2014. Participants were from California, Vermont, Washington State, North Carolina and New Hampshire. Each woman’s vital statistics and risk factors were documented. Lifetime breast cancer risks were calculated using the Gail model or by assessing breast cancer history among first-degree relatives.

Just over 1% of participants had lifetime breast cancer risks of greater than 20%. Women who had lower risks were more likely to undergo MRI if they had one first-degree relative with breast cancer or if they had dense breasts on screening mammography. Among all women, those with lifetime breast cancer risks of 15-19% underwent MRI almost three times more frequently than women with a less than 15% lifetime risk.

During the time period studied, over 80% of the screening breast MRI’s performed were done for women who did not meet national criteria for the modality. The investigators calculated that, with 39.3 million screening mammograms performed annually in the United States, 140,000 breast MRI’s would be performed inappropriately.

This study opens dialogue about the importance of breast cancer risk assessment in determining the best screening regimen for a woman. Specific criteria should be met before planning for this test. Breast MRI, while helpful for many women, does not add useful information for every woman who undergoes it.