In a Journal of the American Medical Association (JAMA) published study, researchers found that although breast MRI use has more than doubled in a decade, patterns of use do not reflect national cancer screening and treatment guidelines.
Specifically, the researchers found that use of breast MRI as a cancer screening tool in women with a greater than 20% risk for breast cancer rose sharply. However, breast MRI was even more frequently used for new cancer diagnosis, cancer surveillance and as a screening tool in women who did not meet the criteria for a greater than 20% lifetime breast cancer risk. Published guidelines by both the American Cancer Society and the National Comprehensive Cancer Network are in favor of the former and recommend against the later.
The research team included three radiologists and the lead author was Karen J. Wernli, PhD, of Group Health Research Institute in Seattle. They examined data on 8,931 breast MRI examinations and 1,288,924 screening mammograms from women aged 18 to 79 years collected from 2005 through 2009 in five national Breast Cancer Surveillance Consortium registries.
The study authors found that the overall rate of breast MRI from 2005 through 2009 nearly tripled from 4.2 to 11.5 examinations per 1000 women. The most rapid increase occurred between 2005 and 2007 and the majority (40.3%) of breast MRIs had been ordered for diagnostic evaluation. MRIs for breast cancer screening was 31.7% of the total.
In an accompanying editorial, E. Shelley Hwang, MD, MPH, of the Duke Cancer Institute, and Isabelle Bedrosian, MD, of the MD Anderson Cancer Center, noted that the findings showed an opportunity for using electronic health records with decision support tools to reallocate MRI resources where they would do more good. MRIs are costly, they noted, and it was important to help physicians use this type of imaging as appropriately as possible.
While the proportion of women screened using breast MRI at high lifetime risk for breast cancer ( >20%) increased during the study period from 9% in 2005 to 29% in 2009, fewer than 5% of the total number of women who met the high lifetime risk criteria were screened with breast MRI as the cancer guidelines recommend. Furthermore, among those who were screened with breast MRI, three quarters did not meet the high lifetime risk criteria.
“These data clearly indicate the need for better patient selection for breast MRI screening if breast MRI is to be maximally effective,” Hwang and Bedrosian wrote.
The field of breast imaging, including MRI, is one of the fastest growing in radiology. According to a report published earlier this month by the U.S. research and consulting company MarketsandMarkets, the total global breast imaging market (including all modalities) is poised to grow at a compound annual growth rate of 15.37% between 2012 and 2017 and will reach approximately $5 billion.