NO BENEFIT OF PERIOPERATIVE MRI FOR DCIS

Perioperative MRI for patients with ductal carcinoma in situ (DCIS) was not associated with a reduction in locoregional recurrence or contralateral breast cancer development in a large single-center study reported at the 2013 ASCO Breast Cancer Symposium. The study also was presented at a premeeting presscast. According to the investigators, there are no guidelines for appropriate use of MRI around the time of surgery, and the results of this study suggest that it should not routinely be ordered in the perioperative setting because it was not associated with improved outcomes.

“There was no association between the use of perioperative breast MRI and decreased rates of locoregional recurrence and contralateral breast cancer for both the entire cohort and women who did not receive radiotherapy. This adds to the evidence we already have, which indicates that MRI is not necessary for every patient with DCIS," said first author Melissa L. Pilewskie, MD, of Memorial Sloan-Kettering Cancer Center. Dr. Pilewskie said that MRI screening comes with a high cost and a fairly high false positive rate leading to additional tests and workups. She added that there are situations where perioperative MRI may be useful, such as in patients with clinical symptoms or physical exam findings not explained by mammogram.

Study Details

The retrospective study was based on a prospectively maintained database of 2,321 women with DCIS who underwent surgery between 1997 and 2010 at Memorial Sloan-Kettering Cancer Center. Of that group of women, 596 had an MRI before or immediately following surgery, while 1,725 women did not. At a median follow-up of 59 months, no significant difference in the 5-year locoregional recurrence rates was observed between those who had an MRI vs those who did not (8.5% vs 7.2%, respectively).

Women who had an MRI were younger, more likely to be premenopausal, have a family history of breast cancer, have a clinical presentation, receive radiotherapy and endocrine therapy, be treated in later calendar years, and had fewer close or positive margins. These findings suggest that oncologists were more likely to order an MRI in women at higher risk and may explain the slightly higher incidence of recurrence in patients who had an MRI, said Dr. Pilewskie.

In an analysis adjusted for patient characteristics and risk factors associated with breast cancer recurrence, use of MRI was not associated with lower 5-year rates of locoregional recurrence or contralateral breast cancer (3.5 years in both groups). At 8 years, the rates of locoregional recurrence were 14.6% for those who had an MRIs 10.2% for those who did not. The 8-year rates of contralateral breast cancer were 3.5% and 5.1%, respectively.

Lower rates of locoregional recurrence were significantly associated with radiotherapy, endocrine therapy, and margin status, Dr, Pilewskie said.

No Improvement in Outcomes

According to Dr. Pilewskie, previous studies indicate that perioperative MRI does not reduce the need for reexcision in women with DCIS. In her opinion, the evidence to date suggests that routine perioperative MRI does not improve either short- or long-term outcomes for patients with DCIS. Dr. Pilewskie said that future research should focus on areas where MRI has the potential to improve outcomes, for example, in predicting a change in surgical management following neoadjuvant therapy for invasive breast cancer, or in more cost-effective short-sequence MRI screening techniques.