November 20, 2013
Improved Trends In Breast Cancer MRI Screening
Rebekah Eliason for redOrbit.com – Your Universe Online
Breast cancer awareness has encouraged many women to take screening measures more seriously. A new study discovered that the number of women undergoing breast MRI (magnetic resonance imaging) has almost tripled from 2005 to 2009 with an increase of four to eleven exams for every 1000 women.
Increasingly, breast MRI tests are used, but the procedure's high degree of sensitivity causes high false positive rates. According to the American Cancer Society, breast MRI is a suggested test for screening asymptomatic women who are at risk for breast cancer when they are known to carry the BRCA gene mutation, have first degree relatives of a known BRCA gene mutation carrier who are themselves untested, or have greater than 20 percent lifetime risk for breast cancer.
Karen Wernli, PhD, is an assistant investigator at Group Health Research Institute. She explained, “Our findings suggest that there have been improvements in appropriate use of breast MRI, with a smaller proportion of examinations performed for further evaluation of abnormal mammogram results and symptomatic patients, and more breast MRI performed for screening of women at high risk.”
Of the women in the study who were screened using breast MRI, the number of participants with a high lifetime risk of breast cancer rose from nine percent to 29 percent between the years 2005 and 2009.
"We found that use of breast MRI for breast cancer screening—rather than diagnosis—is rising, as is appropriate," said Dr. Wernli, who is also an affiliate assistant professor of health services at the University of Washington School of Public Health.
The number of breast MRIs that were used for diagnosis fell and the proportion whose purpose was for screening increased during the period of the study. Screening is the process routinely performed in the absence of suspicion and a diagnostic evaluation is the tests ran after other breast imaging such as mammography and ultrasound.
The purpose of a diagnostic evaluation with breast MRI is to try and avoid a biopsy but is not a recommended procedure before a breast cancer diagnosis. Following a diagnosis there are some who utilize breast MRI to evaluate the extent of the disease.
Two studies found that breast MRI is currently used more for screening than diagnosis. Of those screened, more women with an average risk are utilizing the technology than women with higher risk. Encouragingly, that pattern is improving.
Dr. Wernli said, “Our study suggests breast MRI is being used better. To prevent the underuse by women at high risk, and overuse by those at average risk, we need to strengthen the network of providers, like genetic counselors, who can provide women with the breast cancer risk counseling that they need.”
The study used data from over 6700 women who received breast MRI and is one of the first of its kind used to understand why women are receiving the test. Dr. Wernli explained, “We took a snapshot of how doctors are interpreting the guidelines and using this new technology.”
The study was published in JAMA Internal Medicine. The research was made possible by the Breast Cancer Surveillance Consortium, which is the nation’s largest and most comprehensive collection of information on screening for breast cancer and is funded by the National Cancer Institute.