Newly diagnosed breast cancer patients should undergo a preoperative MRI exam even if their breasts are not dense, a new study indicates. The study found no difference between the usefulness of 3T breast MRI in detecting additional malignancies and high risk lesions in dense versus non-dense breasts.

"There are currently no guidelines that define the role of breast density in determining if a preoperative MRI should be performed. However, anecdotally, we know that preoperative MRI exams tend to be ordered more frequently in younger patients and/or patients with dense breast tissue," said Reena Vashi, M.D., one of the authors of the study.

The study of 127 patients, conducted at Yale University School of Medicine in New Haven, CT, found that 3T MRI detected additional malignancies in 26% of patients who had breasts that were not considered dense and in 25% of patients with dense breasts, said Dr. Vashi. There was no difference in the patients with dense breasts compared to those without dense breasts in regard "to the size of lesions detected, or the distribution of the lesions," Dr. Vashi said. In both populations, a significant and statistically similar percentage of patients had unsuspected additional cancers in the opposite breast or in a separate quadrant from the known cancer in the same breast, necessitating a change in surgical management.

This study provides incentive for more research, said Dr. Vashi. "If these results are reproducible, we propose that the decision to perform preoperative breast MRI not be influenced by breast density," she said.

The study was presented May 4 at the American Roentgen Ray Society Annual Meeting in Vancouver, Canada.