Study Suggests Preoperative MRI Unnecessary for Many Early-Stage HR-Negative Breast Cancer Patients

Routine use of preoperative breast MRI may not improve outcomes for all patients with early-stage breast cancer, according to new research presented this week at the San Antonio Breast Cancer Symposium (SABCS). The findings suggest that women with stage 1 or 2 hormone receptor (HR)-negative cancers derive little to no benefit from the additional imaging, which is often ordered to guide surgical planning.

While MRI is widely used to gain a more comprehensive view of tumor extent, the study shows that skipping the exam does not negatively impact long-term outcomes in this specific patient population. In fact, avoiding the scan may help prevent unnecessary testing, delays in care and higher costs.

“These costs and delays could be justified if there were demonstrable improvement in patient outcomes associated with the use of MRI, but its impact on oncologic outcomes has been understudied,” said Isabelle Bedrosian, MD, lead investigator and surgical oncologist at The University of Texas MD Anderson Cancer Center. “For years, the underlying assumption has been that detecting additional disease by MRI, so that it can be surgically removed, was an important way to reduce the risk of disease recurrence. We designed the clinical trial to test that assumption, setting out to determine whether detecting and removing areas of disease not detected by mammography translated to improved long-term outcomes.”

The study followed 319 women who had newly diagnosed stage 1 or 2 HR-negative breast cancer. All were eligible for lumpectomy and had no BRCA mutations, no bilateral disease and no previous breast cancer. Participants were randomized into two groups—one that underwent preoperative MRI and one that did not—and were tracked for five years.

The results revealed minimal differences between the two groups. Locoregional recurrence-free survival rates were 93.2% for women who had an MRI, compared to 95.7% for those who did not. Distant recurrence-free survival was roughly equal in both groups at about 94%, and overall survival was also similar—92.9% for the MRI group versus 94.1% for the no-MRI group.

“Our results further imply that there is no clinical utility to using preoperative MRI for the diagnostic workup of breast cancer patients to guide surgical treatment,” Bedrosian said. “We conclude that the routine use of MRI in this context is not warranted.”

The study is specific to early-stage HR-negative breast cancers, and its conclusions may not apply to other subtypes or patients with genetic mutations. The average age of participants was 58.9 years at the time of enrollment, which may also influence how broadly the findings can be applied. Nonetheless, the results add to growing evidence that imaging strategies should be more selectively tailored to avoid overtreatment without compromising patient outcomes.