Although the ACS guidelines find screening MRIs of uncertain value for breast cancer survivors, a newly published study shows the scans can be useful for finding tumors in the opposite (contralateral) breast of women newly diagnosed with the disease.
As many as 10% of women with breast cancer develop a new tumor in the opposite breast, even though nothing is found when they are checked with mammograms and physical exams at the time of their original diagnosis.
Finding these cancers earlier could help women make treatment decisions (some women with cancer in just one breast opt to have both breasts removed as a precaution), and might spare them from extra rounds of surgery and chemotherapy later.
Researchers from the University of Washington Medical Center in Seattle studied 969 newly diagnosed breast cancer patients to see if MRIs could find contralateral cancers that mammograms and physical exams missed. The scans found 30 early-stage tumors the other tests could not detect, and missed only 3.
“This study gives us a clearer indication that if an MRI of the opposite breast is negative, women diagnosed with cancer in only one breast can more confidently opt against having a double (or bilateral) mastectomy,” says John E. Niederhuber, MD, director of the National Cancer Institute, which sponsored the study.
The results appear in the New England Journal of Medicine. The study was released to coincide with the publication of the new ACS guidelines for MRI screening in high-risk women.