Comparative effectiveness of MRI in breast cancer (COMICE) trial: a randomised controlled trial

MRI might improve diagnosis of breast cancer, reducing rates of reoperation. We assessed the clinical efficacy of contrast-enhanced MRI in women with primary breast cancer.We undertook an open, parallel group trial in 45 UK centres, with 1623 women aged 18 years or older withbiopsy-proven primary breast cancer who were scheduled for wide local excision after triple assessment. Patients were randomly assigned to receive either MRI (n=816) or no further imaging (807), with use of a minimisation algorithm incorporating a random element. The primary endpoint was the proportion of patients undergoing a repeat operation or further mastectomy within 6 months of random assignment, or a pathologically avoidable mastectomy at initial operation. Analysis was by intention to treat.