A research found that the routine use of MRI for newly diagnosed breast cancer will not improve the margin status or attempts at breast-conserving therapy (BCT) but may actually delay treatment and increase mastectomy rates.

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, from Fox Chase Cancer Center, Philadelphia, and colleagues state.

The study involved 577 patients who were evaluated at a multidisciplinary breast cancer clinic from July 2004 to December 2006. Out of total, 130 patients had pretreatment MRI.

MRI usage rates increased from 13% to 24% during 2004 to 2005 and 27% in 2006.

The researchers reported that MRI usage correlated with younger patient age, but had no link with preoperative chemotherapy, family history of breast or ovarian cancer presentation, or tumor. In addition, the report showed that MRI delay was for an average of 22.4 days in treatment associated with MRI.

Overall, breast-conserving therapy was performed in 320 of 419 women with complete surgical data. Usage of MRI raised the odds of mastectomy by 80% (p = 0.024). MRI use also 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.