Breast MRI prior to breast-conserving treatment does not improve outcome

February 6, 2008

NEW YORK (Reuters Health) - Although magnetic resonance imaging (MRI) of the breast provides advantages over mammography, and is increasingly used to evaluate candidates for breast-conservation treatment (BCT), it does not improve the outcome of BCT in women who have received radiation therapy for early-stage invasive breast carcinoma or ductal carcinoma in situ, according to a recent study.

The retrospective, nonrandomized study is reported in the January 20 issue of the Journal of Clinical Oncology.

Dr. Lawrence J. Solin at the Hospital of the University of Pennsylvania and colleagues reviewed the records of 756 women who had undergone BCT, including definitive radiotherapy, at that hospital during 1992 to 2001.

Routine breast imaging included conventional mammography, with correlation ultrasound as indicated. In addition, 215 (28%) of the patients underwent a breast MRI at the time of initial diagnosis and evaluation.

Surgical treatment included complete gross excision of the primary tumor, and adjuvant systemic therapy was added as indicated, with most women who received adjuvant hormonal treatment receiving tamoxifen.

Because the study was retrospective and nonrandomized, the MRI and non-MRI groups differed slightly. The patients who received MRI were slightly younger (median 53 years versus 56) and also had slightly more favorable clinical characteristics, including tumor size.

The median follow-up for all patients was 4.6 years. The numbers of patients alive at 5 and 8 years were 340 and 158, respectively.

The researchers found no differences, after adjusting for age, between the MRI and non-MRI groups in terms of overall survival, cause-specific survival, freedom from distant metastases and contralateral breast cancer.

They conclude that "the use of breast MRI was not associated with an improvement in outcomes after BCT with radiation" and therefore that MRI is "not globally indicated for all patients with early-stage breast cancer at the time of initial diagnosis and evaluation."

However, Dr. Solin and colleagues do not rule out the possibility of "either a small benefit for the use of breast MRI or a benefit for one or more subsets of patients."