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.
