According to the American Cancer Society and the National Comprehensive Cancer Network, the use of breast MRI should be limited to those women who have a greater than 20 percent lifetime risk of breast cancer, or for further evaluation of indeterminate lesions. Furthermore, MRI is not recommended for new cancer diagnoses or routine surveillance. However, according to two new studies published in JAMA Internal Medicine, the use of breast MRI has increased in the last decade, mostly in women who are not at high-risk of developing breast cancer.
The first study, conducted by Dr. Natasha K. Stout of Harvard and colleagues, looked at the records of about 10,500 women in New England, who had a breast MRI between January 2000 and December 2011. They found that use of breast MRI increased from 2003 to 2008 from 6.5 per 10,000 women to 130.7 per 10,000 women. The rate then declined 10 percent and has stayed constant since 2009. Researchers also evaluated women to determine whether or not imaging would be appropriate and found that only 48 percent of those women received breast MRIs.
The second study conducted by Dr. Karen J. Wernli and colleagues at the Group Health Research Institute in Seattle, looked at records from the Breast Cancer Surveillance Consortium from 2005 to 2009 and included about 9,000 breast MRI exams and 1.3 million screening mammograms. They found that the rate of breast MRI tripled in that period. Furthermore, they found that about 40 percent of those MRIs were conducted for the purpose of diagnostic evaluation and about 32 percent were conducted for the purpose of breast cancer screening.
According to Dr. Stout, Our data suggest that the majority of women who underwent screening for breast MRI did not meet the recommended criteria for appropriate use, whereas many who did meet the criteria did not undergo screening breast MRI. However, to clearly understand appropriateness of use, better documentation of breast cancer risk is needed.
ACSH s Dr. Elizabeth Whelan adds, With this increased use of breast MRI in patients who are not at appropriate risk, patients will be subject to the risks associated with over-screening and over-diagnosis, including being subjected to unnecessary biopsies, surgeries, anxiety and even radiation and chemotherapy. The guidelines on appropriate use of breast MRI must be communicated more clearly to doctors and thence to patients, to ensure that the women who should be receiving breast MRIs are correctly identified and those who are not of appropriate risk can avoid the procedure.