More than a quarter of breast cancer patients who had an MRI examination before their initial surgical treatment had their treatment change, according to a study out of Yale University School of Medicine.

The study included 110 who had an MRI examination before treatment and 374 who did not undergo an MRI examination. “MRI prompted biopsy of 70 sites in 44 patients, said Carol Lee, MD, an author of the study, now at Memorial Sloan Kettering Cancer Center in NY. Sixteen additional sites of cancer were found in 13 (12%) women, she said.

Surgical treatment was changed in 31 (28%) cases, she added. Fifteen patients had mastectomy rather than lumpectomy. Six had more extensive lumpectomy and three had treatment for cancer that was detected in the opposite breast. “Seven others made a decision to have bilateral mastectomy after a suspicious finding was seen on MRI but before additional cancer was confirmed by a biopsy; it turned out that none had cancer in the contralateral breast” Dr. Lee noted.

“While we can’t show definitively that these women made the choice to have a mastectomy due to concerns generated by findings on the MR images, this remains a possibility, and patients and their doctors need to take this into consideration before deciding to have an MRI examination before treatment,” Dr. Lee said.

Adding an MRI examination also delayed treatment. “The mean interval between diagnosis and definitive surgery in the group that had the MRI examination was 41 days compared to 27 days for the patients who did not undergo an MRI examination,” she said.

“Breast MRI is a very useful tool for assessing extent of tumor in the breast, however, there are downsides that need to be taken into consideration,” Dr. Lee emphasized.

The full results of this study will be presented on Tuesday, April 15, 2008 during the American Roentgen Ray Society’s annual meeting in Washington, DC.

Source: American Roentgen Ray Society (ARRS)