SABCS 2025: Diagnostic breast MRI may be unnecessary for some patients with early-stage breast cancer

MD Anderson Research News December 11, 2025

• Study finds pre-surgical MRI does not improve five-year rates of local regional free survival over mammograms alone in patients with stage I/II HR-negative breast cancer

• Breast MRI is commonly included as part of the diagnostic work-up of breast cancer in addition to mammography to determine the extent of the cancer

• Experts say MRI may lead to additional testing, delays in surgery and increased costs

SAN ANTONIO, DECEMBER 11, 2025 – Adding breast magnetic resonance imaging (MRI) to a diagnostic mammogram did not reduce five-year cancer recurrence rates for patients with stage I/II hormone receptor (HR)-negative breast cancer, according to researchers at The University of Texas MD Anderson Cancer Center. 

The Phase III Alliance A011104/ACRIN6694 trial found that five-year locoregional recurrence rates were 6.8% in patients who received an MRI as part of a diagnostic work-up and 4.3% in those who did not. These data were presented today at the San Antonio Breast Cancer Symposium (SABCS) by principal investigator Isabelle Bedrosian, M.D., professor of Breast Surgical Oncology (Abstract GS2-07).

“We have long assumed that finding more breast cancer on an MRI and removing it with surgery would help lower the chance of a patient’s cancer coming back,” Bedrosian said. “When you look at our findings alongside earlier trials, the message is clear: adding MRI before surgery doesn’t improve results for patients -- and may not have to be used as a standard part of the diagnostic process.”

What are the findings of the study? 

The trial enrolled 319 patients between 2014 and 2018 with newly diagnosed stage I or II HR-negative breast cancer. These patients were eligible for lumpectomy (surgery) and did not have germline BRCA1/2 mutations, bilateral breast cancer or a history of prior breast cancer. All patients had undergone diagnostic mammography with or without ultrasound prior to trial enrollment.  Patients were randomly assigned to undergo additional imaging by breast MRI (161 patients) or to receive no further imaging (158 patients).

Not only did breast MRI not impact five-year recurrence rates, but there were also not significant differences between groups for five-year distant recurrence-free survival nor overall survival. 

A small subset of patients with tumor subtypes (HR- HER2+ and HR-HER2-) and those over the age of 50 at diagnosis also showed no benefit to MRI.

What does this study clarify about diagnostic MRI before surgery?

Breast MRI is a common part of the diagnostic evaluation because it can reveal cancer that mammography might not detect. However, the evidence that it improves surgical outcomes for patients has been limited.

“We believe the reason MRI did not reduce recurrence rates may be twofold,” Bedrosian said. “It is possible that MRI didn’t uncover many lesions that mammography hadn’t already found, or perhaps identifying and surgically removing those additional lesions was not important to reducing risk of the cancer coming back. It’s possible that in the group that did not receive MRI, radiation and chemotherapy effectively treated the occult areas of disease”. 

Experts are now analyzing how often breast MRI identified additional lesions in the trial population to better understand why breast MRI did not impact oncologic outcomes.

What are the limitations of this study? 

Limitations included that most patients involved in the trial had breast cancer that hadn’t spread to their lymph nodes, which may partly explain why recurrence rates were low overall. Despite being open to women of all ages, the study enrolled mostly older women who may have been less likely to benefit from breast MRI. 

***

This study was supported by the National Cancer Institute of the National Institutes of Health. A full list of collaborating authors, disclosures and funding sources can be found with the abstract.