Supplementary Material for: Assessment of Adjuvant Trastuzumab-Associated Cardiac Toxicity in Korean Patients with Breast Cancer: A Single-Center Analysis

Background: We performed this analysis to investigate the clinical presentation of trastuzumab-associated cardiac toxicity in Korean women. Method: 124 patients treated in a single institute from January 2006 to November 2011 with adjuvant trastuzumab therapy following primary surgery were identified from a database. We evaluated the cumulative incidence of cardiac toxicity, associated risk factors, and changes in cardiac function during trastuzumab treatment. Results: The median age of patients was 50 years (range 27-73). After 12 months of follow-up, the cumulative incidence of cardiac toxicity was 12.1% (grade I: 8.1%, grade II: 0.8%, grade III: 3.2%). In total, 4% of patients discontinued treatment due to cardiac dysfunction. The left ventricular ejection fraction (LVEF) recovered in all patients who discontinued or delayed treatment due to cardiac dysfunction following treatment discontinuation. The degree of the decrease in LVEF was large at 6 months after the initiation of treatment. A lower LVEF at baseline (Conclusions: The low incidence of cardiac toxicity and the reversibility of cardiac dysfunction may validate the safety of trastuzumab treatment in Korean women with an acceptable baseline LVEF.

背景：本分析旨在探究韩国女性患者中曲妥珠单抗（trastuzumab）相关心脏毒性的临床表现。
方法：本研究从数据库中筛选出2006年1月至2011年11月期间，在单中心接受原发手术后辅助曲妥珠单抗治疗的124例患者。本研究评估了曲妥珠单抗治疗期间心脏毒性的累积发生率、相关危险因素以及心脏功能的变化情况。
结果：患者的中位年龄为50岁（范围27~73岁）。经过12个月的随访，心脏毒性的累积发生率为12.1%（Ⅰ级：8.1%，Ⅱ级：0.8%，Ⅲ级：3.2%）。总计有4%的患者因心功能不全中断治疗。所有因心功能不全停药或延迟治疗的患者，在停药后其左心室射血分数（left ventricular ejection fraction, LVEF）均恢复正常。治疗开始后6个月时，左心室射血分数的下降幅度最为显著。基线左心室射血分数较低
结论：心脏毒性发生率较低且心功能不全具有可逆性，这证实了基线左心室射血分数处于可接受范围的韩国女性患者接受曲妥珠单抗治疗的安全性。