Impact of magnetic resonance imaging in determining surgical management in breast cancer

While conventional triple assessment (clinical, needle biopsy and mammography) has a high sensitivity in the diagnosis of symptomatic breast cancer, it has limitations in defining the extent of disease within the breast and the axilla. The purpose of this study was to evaluate the clinical settings in which pre-operative magnetic resonance imaging (MRT) may be of additional value to triple assessment. Eighty-six patients with breast cancer (including one bilateral cancer) diagnosed at triple assessment underwent preoperative contrast enhanced MRI. Based on clinical and mammographic findings and patient's choice of treatment (but not MR findings), 49 cancers were treated by wide local excision, of whom 16 (33%) had resection margin involvement. Residual disease at re-excision was detected in 8 of these 16 patients. The extent of residual disease in the re-excision specimen correlated accurately with the extent of contrast enhancement on MRI in all cases. There was good size correlation between histological and MRI measurement of invasive tumour (r(2)=0.93) size compared with mammographic measurement of tumour size (r(2)=0.59). MRT was also more accurate than mammography in depicting multifocal/multicentric tumours (86% Versus 50%), intraduct extension associated with invasive tumours and assessment of the nipple-retro-areolar complex. In conclusion, MRI may be of value in planning definitive surgical resection of breast cancer. Its incorporation into clinical use may have an impact on local recurrence rates and on the number of patients considered suitable for breast conservation.