On univariate analysis, an age of ≤ 40 years (p < 0.001) and T2 stage (p = 0.006) were significantly associated with a high risk of LRR, and the biological subtype was marginally associated with high LRR. With respect to the biologic subtypes, the 7-year cumulative incidence of LRR was 2.2% for luminal A, 7.0% for luminal B, 5.1% for luminal HER2, 4.4% for HER2+, and 5.1% for TN (p = 0.095). The use of trastuzumab in patients with HER2+ did not affect LRR (Table 2). On multivariate analysis (Table 3), an age of ≤ 40 years (HR, 3.3; p < 0.001) and T2 stage (HR, 1.3; p = 0.013) were independently associated with a high risk of LRR.