In about twenty percent of women with breast cancer who plan to undergo lumpectomy, breast magnetic resonance imaging reveals important information that alters their treatment plan, University of Florida surgeons say.

M-R-I, which isn’t routinely administered to these patients, can find additional cancerous areas that evaded detection, discover cancer in the opposite breast that standard imaging tests such as mammography and ultrasound missed, or determine a tumor is larger than expected.

Some end up needing a total mastectomy instead of breast-conserving lumpectomy, and surgeons say M-R-I can help confirm which women are indeed candidates for a breast-sparing operation.

The findings were presented at the Southern Surgical Association’s annual meeting and will be published in May in the Journal of the American College of Surgeons.

The study looked at seventy-nine women who had localized noninvasive or early stage invasive breast cancer and were planning to have a lumpectomy. They had undergone preoperative M-R-I and, when indicated, MRI-directed biopsies for evaluation of suspicious areas.

Recommendations published in the New England Journal of Medicine touted the merits of annual breast M-R-I for women with a high lifetime risk of cancer, but didn’t advocate widespread use.

But U-F surgeons say high-quality preoperative M-R-I along with M-R-I-guided biopsy could benefit many patients because it detects cancers that otherwise would be missed… particularly in women with dense breasts difficult to see on mammography or in those with smaller lesions hard to pinpoint on ultrasound. Early diagnosis and treatment could reduce recurrence rates, researchers hope.