MRIs Helpful in Breast Cancer Diagnosis
Scans can often help detect breast tumors missed by mammograms.
March 28, 2007 — -- Women with an increased risk of breast cancer benefit from magnetic resonance imaging (MRI) screening, according to the American Cancer Society.
Based on new evidence, these women -- up to 1.4 million in the United States -- are now encouraged to get annual MRIs in addition to mammograms.
"ACS has recommended yearly breast cancer screening beginning at age 40 for some time now," said Dr. Robert Smith, director of cancer screening at the American Cancer Society. "But we have always known that there is a subgroup that is at greater risk, such as those who have a strong family history of the disease."
On the basis of new evidence, the guidelines now recommend annual MRIs for breast cancer screening for women with approximately 20 percent or greater lifetime risk of breast cancer.
This would include women with a strong family history of breast or ovarian cancer, as well as others who have specific mutations in BRCA1 or BRCA2, which are genes associated with breast cancer.
Women who have been treated with radiation to the chest for Hodgkin's disease should also have annual MRIs to check for breast cancer.
As the new guidelines were being announced, the New England Journal of Medicine also released the results of a national study today that suggest women who have cancer diagnosed in one breast should get an MRI of the other breast.
The study, led by Dr. Constance Lehman of the University of Washington Medical Center and the Seattle Cancer Alliance, looked at a total of 969 women with recent diagnoses of cancer in one breast and no abnormalities on clinical exam and mammography in the second breast.
They found that the MRI detected cancer in the opposite breast in 30 of 969 women (or 3.1 percent) who had recently been diagnosed with cancer in one breast only. The cancers in the opposite breast were missed by previous mammographies and clinical exams.
"When someone is first diagnosed with breast cancer, she has a 10 percent lifetime increased risk of getting another cancer in either of the breasts," said Dr. Carl Jaffe of the National Cancer Institute, which sponsored the study.
