Preoperative breast MRI can reduce the rate of tumor-positive resection margins and reoperations in patients undergoing breast-conserving surgery.

ABSTRACT

OBJECTIVE: In breast cancer patients eligible for breast-conserving surgery, we evaluated whether the information provided by preoperative MRI of the breast would result in fewer tumor-positive resection margins and fewer reoperations. SUBJECTS AND METHODS: The study group consisted of 123 consecutive patients diagnosed with either breast cancer or ductal carcinoma in situ eligible for breast-conserving surgery between April 2007 and July 2010. For these patients, a first plan for breast-conserving surgery was made on the basis of clinical examination and conventional imaging. The final surgical plan was made with knowledge of the preoperative breast MRI. The rates of tumor-positive resection margins and reoperations were compared with those of a historical control group consisting of 119 patients who underwent 123 breast-conserving procedures between January 2005 and December 2006. The percentage of change in the surgical plan was recorded. RESULTS: Preoperative breast MRI changed the surgical plan to more extensive surgery in 42 patients (34.1%), mainly to mastectomy (29 patients, 23.6%). Ninety-four patients underwent 95 breast-conserving procedures. Significantly fewer patients had tumor-positive resection margins than in the control group (15.8%, 15/95 versus 29.3%, 36/123; p < 0.01). Patients in the study group underwent significantly fewer reoperations compared with the historical control group (18.9%, 18/95 vs 37.4%, 46/123; p < 0.01). CONCLUSION: Preoperative breast MRI can substantially decrease the rate of tumor-positive resection margins and reoperations in breast cancer patients eligible for breast-conserving surgery.