Preoperative Breast MRI Offers No Benefit in Early-Stage Hormone Receptor-Negative Cancer
A new study presented at the San Antonio Breast Cancer Symposium challenges the routine use of preoperative breast MRI for patients with stage I or II hormone receptor-negative breast cancer, finding no significant impact on locoregional recurrence rates.
SAN ANTONIO – For patients diagnosed with early-stage, hormone receptor-negative breast cancer, adding a preoperative breast MRI to standard diagnostic mammography does not improve outcomes, according to research unveiled at the San Antonio Breast Cancer Symposium this week. The findings suggest that the widespread practice of utilizing MRI for surgical planning in these cases may be unnecessary and potentially harmful.
Researchers found comparable five-year locoregional recurrence rates between patients who underwent breast MRI in addition to diagnostic mammography and those who did not, leading them to conclude that the “clinical benefit of MRI is lacking.”
“Use of breast MRI has become widespread in the care of breast cancer patients, driven by consensus within the field that MRI was more sensitive at detecting disease than mammography, providing both a more accurate assessment of the size of the index lesion and identifying additional areas of disease,” explained Isabelle Bedrosian, MD, professor of breast surgical oncology at The University of Texas MD Anderson Cancer Center. “The assumption for a long time was that detecting, and treating, based on MRI extent of disease was important to optimizing patient outcomes — we set out to test this assumption.”
Study Details and Methodology
The phase 3 Alliance A011104 trial enrolled 319 patients (median age, 58.9 years) with stage I or II hormone receptor (HR)-negative breast cancer, encompassing triple-negative, ER/PR-negative, and HER2-positive subtypes. Participants were randomly assigned to either undergo breast MRI following mammography (n = 161) or proceed without MRI (n = 158).
The majority of patients presented with T1 tumors (72.1%) and node-negative disease (93.4%), with approximately 20% being HER2-positive. Systemic chemotherapy was administered to 85% of the cohort, with nearly 18% receiving it prior to surgery. A significant proportion – 91.9% – underwent breast-conserving surgery as their initial procedure, with no statistically significant difference observed between the MRI and no-MRI groups.
Among patients receiving neoadjuvant chemotherapy, the overall pathologic complete response rate was 39.3%, slightly lower in the MRI group (29%) compared to the no-MRI group (52%), although this difference was not statistically significant (P = .10). Adjuvant radiation therapy rates were consistent across both groups (85.4% no MRI vs. 85% MRI).
Key Findings: No Discernible Benefit
After a median follow-up of just over five years (61.1 months), the study revealed no difference in locoregional recurrence between patients who received preoperative breast MRI and those who did not.
“This adds to the body of evidence that there does not appear to be a clinical benefit from routine use of breast MRI for purposes of surgical planning,” Bedrosian stated. “Our primary finding that MRI does not improve local regional control aligns with the BREAST-MRI Trial reported in 2023 out of Brazil — although the cohort for BREAST-MRI trial was primarily HR-positive — as well as with available retrospective studies that have reported local recurrence outcomes based on use of preoperative breast MRI.”
Specifically, five-year locoregional control was 93.2% in the MRI group versus 95.7% in the no-MRI group (HR = 1.1; 95% CI, 0.3–3.9). The five-year distant recurrence-free rate was 94.3% and overall survival was 92.2%, with no observed differences between the groups.
Balancing Risks and Benefits
Bedrosian emphasized that breast MRI is not without potential drawbacks. “Breast MRI is associated with known harms, including additional biopsies, increased rates of mastectomy, and delays to surgery,” she noted. “It is important to balance these harms against the clinical benefits. Data from A011104 shows no benefit to MRI for reducing local regional recurrence. This finding, coupled with the preponderance of data showing no benefit for MRI in reducing reoperation rates suggests that harms appear to be greater than benefits, and thus routine use of breast MRI in newly-diagnosed patients is not warranted.”
These findings suggest a need to re-evaluate current clinical practices and potentially reduce the reliance on routine preoperative breast MRI in patients with early-stage, hormone receptor-negative breast cancer.
Source: Bedrosian I, et al. Abstract GS2-07. Presented at: San Antonio Breast Cancer Symposium; Dec. 9-12, 2025; San Antonio.
Disclosures: The NCI and NIH supported this study. Bedrosian reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.
