Among patients with early-stage breast cancer, surgical remval of MRI-detected disease may not be necessary in the context of systemic therapy and radiation therapy, clinical trial results have shown.
Results from the phase 3 Alliance A011104/ACRIN 6694 trial were shared during a press briefing at the 2025 San Antonio Breast Cancer Symposium (SABCS).
The number of patients free from local regional recurrence (LRR) at 60 months was 93.2% in the MRI arm and 95.7% in the no MRI arm; the median LRR was not evaluable in both arms. Among patients younger than 50 years old, LRR events occurred in two of 30 patients in the MRI arm and none of 20 patients in the no MRI arm.
Glossary
Local–Regional Recurrence: The cancer has come back in the same area where it first started or in nearby lymph nodes. It has not spread to distant parts of the body.
Distant Recurrence-Free: when the cancer has not come back in other parts of the body (such as the lungs, liver, bones, or brain). It means there is no sign of the cancer spreading far from where it originally began.
Overall Survival: This refers to how long patients are alive after their diagnosis or treatment, no matter the cause of death. It is a common way for doctors and researchers to understand how effective a treatment may be.
Additionally, of patients with estrogen receptor (ER)– or progesterone receptor (PR)–negative, HER2-positive breast cancer, LRR events occurred in one patient of 30 in the MRI arm and one of 31 in the no MRI arm. Of patients with ER/PR-negative, HER2-negative breast cancer, LRR events occurred in nine of 117 patients in the MRI arm and five of 120 in the no MRI arm.
The five-year distant recurrence-free rate (DRFR) rate was 94.3% in all patients; in the MRI arm, eight of 147 patients experienced a distant recurrence event, and in the no MRI arm, eight of 151 patients experienced an event.
The five-year overall survival (OS) rate was 92.2% in all patients; 12 of 147 patients in the MRI arm experienced an OS event, and 13 of 151 patients in the no MRI arm experienced an OS event.
“What we find is that the rate of LRR overall is quite low. It is lower than what we had anticipated when we were designing the study,” stated presenting study author Dr. Isabelle Bedrosian, professor in the Department of Breast Surgical Oncology of the Division of Surgery at The University of Texas MD Anderson Cancer Center, during the presentation. “We identified that the preoperative breast MRI did not improve any of the oncologic outcomes that we measured — LRR, DRFR and OS.”
A total of 319 patients were randomly assigned to receive or not receive a breast MRI. Breast MRI was administered within 30 days of mammography, and following MRI, patients underwent either breast-conserving therapy or mastectomy. All patients underwent surgery within six weeks of registration.
Eligible patients for the trial had newly diagnosed breast cancer of clinical stage 1 to 2 (T1 to T3N0 or T0 to 2N1) with HR-negative status and either HER2-positive or HER2-negative status. They were also eligible for breast-conserving surgery (BCS) and had no known germline BRCA1/2 alterations. Notably, there was an amendment such that patients at diagnosis did not have to be BCS eligible, but they were still required to be eligible for BCS following neoadjuvant chemotherapy.
The trial was hosted across 73 sites, of which 55% were academic and 45% were community centers.
The median age of patients was 58 years in the MRI arm and 61 years in the no MRI arm, with clinical stage T1 noted in 70.8% and 73.4%, respectively, clinical stage N0 in 93.8% and 93.0%, and HER2-positive status in 19.9% and 19.6%.
Initial breast surgery was initial BCS in 91.2% of the MRI arm and 92.7% of the no MRI arm; axillary surgery was sentinel lymph node biopsy alone in 86.4% and 94.7%, respectively; final margin status was positive in 6.8% and 6.6%; and adjuvant radiation was received by 85% and 85.4%.
“Results from [this trial] add to the body of evidence that preoperative breast MRI for staging patients with newly diagnosed breast cancer does not result in improved oncologic outcomes or improvement in surgical care,” Bedrosian stated. “The routine use of breast MRI for staging of disease does not appear to be warranted.”
Reference
- “Effect of preoperative breast MRI staging on local regional recurrence (LRR) in early stage breast cancer: Alliance A011104/ACRIN 6694” by Dr. Isabelle Bedrosian et al., presented at the 2025 San Antonio Breast Cancer Symposium; December 9-12, 2025; San Antonio, TX. Abstract GS2-07.
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