Background: The guidelines of the American Cancer Society and the National Comprehensive Cancer Network (NCCN) advise considering breast MRIs if a woman’s lifetime risk of breast cancer is greater than 20 percent. In the general USA population, the population lifetime risk is 12%. Women at high risk include those with the genetic mutations BRCA1 and BRCA2, those who had chest radiation during childhood, or those with a first-degree relative known to have the BRCA1 or BRCA2 mutation. For huh-risk women, annual MRIs and mammograms are recommended.
MRI uses a strong magnetic field and radio waves (not X-rays or radiation) to produce a detailed image. A contrast material is injected into a vein to show tissue details. The scan in the USA is expensive: Mediaid reimbursement is $880 to $1600USD for MRRIs of both breasts, and about $300 for a digital mammogram. Fees for women not on this government program vary widely. While MRIs are more sensitive in finding cancers than are mammograms, false positive results are much more likely, and can lead to unnessary testing (including biopsies) and anxiety.
The journal JAMA Internal Medicine recently reported two studies regarding the use of MRI for imaging the breast. The first reported that:
The use of breast MRIs has nearly tripled in recent years, but the women who could benefit the most are not always getting the expensive imaging test.
The researchers observed that more women at high risk are undergoing screening, which suggests that MRI is being used more appropriately. On the other hand, a second study reported that:
Breast MRIs between 2000 and 2011 jumped 20-fold, then declined and stabilized by 2011. But less than half of women with documented genetic mutations that raise the risk of breast cancer got the tests. The majority of women who underwent screening with breast MRI did not meet the recommended criteria for appropriate use, whereas many who did meet the criteria did not undergo screening MRI.
My Take: Fortunately, the US Preventative Task Force (USPSTF) has started updating its recommendations on screening for breast cancer. The USPSTF created a research panel that will frame the scope, conduct, and content of a systematic evidence review. A draft of the Research Plan should be posted for public comment until 11 December 2013. Hopefully, we will get better guidance (and perhaps more importantly adherence to said guidance). We have got to do a better job of targeting breast MRI to those who will truly benefit from it. It is unacceptable to find that of women who got breast MRI for screening, only 21 percent met the American Cancer Society criteria for such screening. While today’s post addresses breast MRI as a screening tool (for those without breast cancer), we need to be more selective in the use of breast MRI for those who already have breast cancer. I’m Dr. Michael Hunter.
The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.
Available now: Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Both can be found at the Apple Ibooks store. Coming Soon for iPad: Understand Breast Cancer in 60 Minutes; Understand Colon Cancer in 60 Minute; Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Thank you.
HealthDay: News for Better Living, 18 Nov 2013; JAMA Internal Medicine 18 Nov 2013.