According to a study led by SCCA's Dr. Constance Lehman, MRI scans of women who were diagnosed with cancer in one breast detected over 90 percent of cancers in the other breast that were missed by mammography and clinical breast exam at initial diagnosis.
Given the established rates of mammography and clinical breast exams for detecting cancer in the opposite, or contralateral breast, adding an MRI scan to the diagnostic evaluation effectively doubled the number of cancers immediately found in these women.
The American College of Radiology Imaging Network (ACRIN) study, supported by the National Cancer Institute (NCI), part of the National Institutes of Health (NIH), appeared in the March 29, 2007 issue of the New England Journal of Medicine.
“We can now identify the vast majority of contralateral cancers at the time of a woman’s initial breast cancer diagnosis,” said Lehman, principal investigator of the ACRIN Breast MRI Trial, professor of radiology and director of breast imaging at the University of Washington and Seattle Cancer Care Alliance. “This means that instead of those women having another cancer diagnosis years after their initial treatment, we can diagnose and treat those opposite breast cancers at the time of the initial diagnosis."
Researchers hope that with breast MRI’s strong ability to predict the absence of a tumor, they can avoid some unnecessary mastectomies and provide women with more reassurance that the breast is disease free.
“Although no imaging tool is perfect, if the MRI is negative, the chance of cancer in that breast is extremely low. A potential outcome that we would be delighted to see is fewer unnecessary bilateral mastectomies,” said Lehman.
An expert panel, of which Lehman is a member, recommended annual screening using MRI in addition to mammography for women with a 20-25 percent or greater lifetime risk of the disease.
Those include women who:
- Have a first-degree relative with a BRCA 1 or 2 mutation and are untested,
- Have a lifetime risk of breast cancer of 20-25 percent or more using standard risk assessment models
- Received radiation treatment to the chest between ages 10 and 30, such as for Hodgkin Disease
- Carry or have a first-degree relative who carries a genetic mutation in the TP53 or PTEN genes
“These guidelines are a critical step to help define who should be screened using MRI in addition to mammography, a question of significant importance as we discover women at very high risk of breast cancer can be diagnosed much earlier when combining the two technologies rather than mammography alone,” said Lehman.