“Without evidence of improved oncologic outcomes as a result, our study does not support the routine use of MRI to select patients or facilitate the performance of BCT,” Dr. Richard J. Bleicher, form Fox Chase Cancer Center, Philadelphia, and colleagues state.
The study, reported in the Journal of the American College of Surgeons for August, featured 577 patients who were evaluated at a multidisciplinary breast cancer clinic from July 2004 to December 2006. Of the patients, 130 had pretreatment MRI.
MRI usage rates climbed during the study period from 13% in 2004 to 24% in 2005 and 27% in 2006.
MRI usage correlated with younger patient age, but showed no association with preoperative chemotherapy, family history of breast or ovarian cancer presentation, or tumor features, the researchers MRI delay in treatment associated with MRI was an average of 22.4 days, the report indicates.
Overall, breast-conserving therapy was attempted in 320 of 419 women with complete surgical data. Usage of MRI increased the odds of mastectomy by 80% (p = 0.024). Moreover, MRI use did not reduce the percentage of patients with positive margins at lumpectomy (21.6% vs. 13.8%), nor did it reduce the BCT to mastectomy conversion rate (9.8% vs. 5.9%).
“We observed that despite its greater sensitivity for cancer detection, MRI is not associated with a decrease in either the need for preexcision for positive margins or initial unsuccessful lumpectomy attempts in patients who ultimately require mastectomy,” the authors conclude. “In the absence of prospective data, our study sounds a cautionary note that the ‘obvious’ benefits of MRI may not be observed in clinical practice.”
J Am Coll Surg 2009;209:180-187.