Impact of Preoperative MRI on Survival Outcomes in Patients with HER2-positive and Hormone Receptor-negative Breast Cancer.

Background Little is known regarding the impact of preoperative breast MRI on the long-term outcomes of patients with breast cancer that is human epidermal growth factor receptor 2 (HER2) positive and hormone receptor negative. Purpose To evaluate the impact of preoperative breast MRI on recurrence-free survival (RFS) and overall survival (OS) in patients with HER2-positive and hormone receptor-negative breast cancer by using propensity score matching. Materials and Methods This retrospective study included women diagnosed with HER2-positive and hormone receptor-negative invasive ductal carcinoma between January 2007 and December 2016. Patients who underwent preoperative MRI (the MRI group) were matched with those who did not (the no-MRI group) using propensity score matching based on 19 clinical-pathologic covariates. RFS and OS were compared using Kaplan-Meier estimates, Cox proportional hazards models, and inverse probability weighting. Results Among 1094 women (median age, 52 years; age range, 24-91 years), 47.81% (523 of 1094) underwent preoperative MRI. The rates of total recurrence and death were 14.3% (75 of 523) and 7.07% (37 of 523) in the MRI group, respectively, compared with 16.5% (94 of 571) and 13.1% (75 of 571) in the no-MRI group. In the propensity score-matched set, preoperative MRI was not associated with total recurrence (hazard ratio [HR], 0.69; 95% CI: 0.47, 1.02; = .06), local-regional recurrence (HR, 0.94; 95% CI: 0.52, 1.70; = .84), contralateral breast recurrence (HR, 0.55; 95% CI: 0.24, 1.25; = .15), or distant recurrence (HR, 0.56; 95% CI: 0.31, 1.03; = .06). OS was not higher with preoperative MRI (HR, 0.63; 95% CI: 0.39, 1.00; = .05). At multivariable analysis, preoperative MRI was not associated with improved RFS (HR, 0.89; 95% CI: 0.67, 1.19; = .44) or OS (HR, 0.73; 95% CI: 0.48, 1.10; = .14). Conclusion Preoperative MRI did not improve RFS or OS in patients with HER2-positive and hormone receptor-negative breast cancer. © RSNA, 2025 See also the editorial by Imbriaco and Ponsiglione in this issue.