Neoadjuvant Chemotherapy and Surgery for Breast Cancer: Preoperative MRI Features Associated with Local Recurrence.

Purpose To investigate the MRI and clinical-pathologic features associated with local-regional recurrence (LRR) in patients who had undergone breast-conserving surgery (BCS) following neoadjuvant chemotherapy (NAC). Materials and Methods In this retrospective, single-institution study between October 2003 and September 2015, 548 consecutive women, consisting of 468 down-staged and 80 preplanned BCS patients (mean age, 45.7 years; range, 22-75 years), underwent preoperative MRI and BCS following NAC. The rate and site of LRR, preoperative MRI features including Breast Imaging Reporting and Data System lexicon, and clinical-pathologic features (age, stage, tumor subtype, histologic grade, lymphovascular invasion, adjuvant chemotherapy, and endocrine therapy) were analyzed with the Cox proportional hazards model to identify independent factors associated with LRR-free survival (LRFS). Results Of the 548 women, 23 (4.2%) had LRR at a median follow-up of 23.1 months. In Cox regression analysis, younger age (ie, ≤ 40 years) (hazard ratio = 2.932; 95% confidence interval [CI]: 1.233, 6.969; P = .015) or the presence of nonmass enhancement on preoperative MR images (hazard ratio = 3.220; 95% CI: 1.274, 8.140; P = .014) was associated with worse LRFS. LRR was more frequently observed in the same quadrant as the original tumor in the down-staged BCS group than in the preplanned BCS group (80.0% [16 of 20] vs 33.3% [one of three]; P = .021). Conclusion Age of 40 years or younger or the presence of nonmass enhancement on preoperative MR images tends to be associated with worse local-regional recurrence-free survival, and local-regional recurrence frequently occurs in the same quadrant as the original tumor in breast cancer patients who undergo breast-conserving surgery following neoadjuvant chemotherapy. © RSNA, 2018.