Magnetic resonance imaging in the planning of initial lumpectomy for invasive breast carcinoma: its effect on ipsilateral breast tumor recurrence after breast-conservation therapy.

BACKGROUND: It remains uncertain whether routine preoperative breast magnetic resonance imaging (MRI) will lead to improved local outcomes after breast-conserving surgery (BCS) and radiation (RT) for invasive carcinoma. The purpose of this study was to determine whether MRI in the planning of the first lumpectomy reduces ipsilateral breast tumor recurrence (IBTR).
METHODS: Using a prospective database, 472 initial lumpectomies from 463 women between 1999 and 2005 were examined. All patients had invasive cancer excised to negative margins on BCS, received RT, and were followed. IBTR rates were calculated by Kaplan-Meier method. Univariate and multivariate analyses were performed to investigate the association between MRI for initial lumpectomies and IBTR outcomes.
RESULTS: MRI was performed before 127 (27%) lumpectomies, while 345 (73%) patients did not have a preoperative breast MRI. At median follow-up of 54 months (range 4.8-111.6 months), there was no significant difference in actuarial 8-year IBTR rates between women with preoperative MRI evaluation and women without MRI (1.8% versus 2.5%, respectively; P=0.67). After adjusting for adjuvant therapies, patient, and tumor characteristics, there continued to be no increased risk of IBTR [hazard ratio (HR) 1.7; P=0.60]. MRI visualization of tumors prior to lumpectomy did not influence the achievement of negative margins and was not associated with lower rates of re-excision (MRI: 11.8% versus no-MRI: 13.3%; P=0.50).
CONCLUSION: MRI evaluation of invasive carcinoma in the planning of initial lumpectomies was not associated with improved local outcomes after BCS with RT in this cohort of patients.