Zhang Kun, Wu Shijie, Zhou Yunxiang, Chen Huihui, Pan Chi
Department of Breast Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People's Republic of China.
Breast Cancer (Dove Med Press). 2025 Sep 5;17:781-791. doi: 10.2147/BCTT.S512846. eCollection 2025.
Thrombocytopenia is a common adverse event associated with trastuzumab emtansine (T-DM1) treatment in patients with HER2-positive metastatic breast cancer. This study aims to evaluate the incidence, clinical characteristics, and risk factors of T-DM1-associated thrombocytopenia.
This retrospective study included patients with breast cancer who received T-DM1. Thrombocytopenia was defined as a platelet count of less than 100 × 10/L. Potential risk factors for thrombocytopenia were analyzed.
The study cohort consisted of 47 patients with a median age of 55 years, including one male patient. Thrombocytopenia was observed in 74.5% of patients during T-DM1 treatment. A total of 63.3% of patients with Ki-67 expression levels ≥30% experienced thrombocytopenia, which was significantly lower than the 94.1% incidence in patients with Ki-67 expression <30% (P=0.034). Patients with completed or ongoing T-DM1 treatment had a thrombocytopenia incidence of 90.5%, compared to 64% in those who discontinued treatment (P=0.036). Although not reaching statistical significance, concurrent radiotherapy was associated with a higher incidence of thrombocytopenia (87.5%). After appropriate interventions, 70% of patients showed restored platelets, while 17.1% required dose reductions.
Thrombocytopenia is a prevalent adverse event during T-DM1 treatment in real-world practice. An increased incidence with concurrent radiotherapy was observed. While the incidence of thrombocytopenia appears to rise with prolonged exposure in completed or ongoing T-DM1, it may have a minor impact on the overall duration of therapy. Future studies should examine these findings to guide prophylactic strategies and interventions for high-risk patients.
血小板减少是HER2阳性转移性乳腺癌患者接受曲妥珠单抗 emtansine（T-DM1）治疗时常见的不良事件。本研究旨在评估T-DM1相关血小板减少的发生率、临床特征及危险因素。
本回顾性研究纳入接受T-DM1治疗的乳腺癌患者。血小板减少定义为血小板计数低于100×10⁹/L。分析血小板减少的潜在危险因素。
研究队列包括47例患者，中位年龄55岁，其中1例男性患者。74.5%的患者在T-DM1治疗期间出现血小板减少。共63.3%的Ki-67表达水平≥30%的患者发生血小板减少，显著低于Ki-67表达<30%患者的94.1%的发生率（P=0.034）。完成或正在接受T-DM1治疗的患者血小板减少发生率为90.5%，而停药患者为64%（P=0.036）。虽然未达到统计学意义，但同时接受放疗与更高的血小板减少发生率相关（87.5%）。经过适当干预，70%的患者血小板恢复，17.1%的患者需要减量。
在实际临床实践中，血小板减少是T-DM1治疗期间普遍存在的不良事件。观察到同时接受放疗时发生率增加。虽然在完成或正在接受T-DM1治疗中，血小板减少的发生率似乎随暴露时间延长而上升，但可能对总体治疗持续时间影响较小。未来研究应检验这些发现，以指导高危患者的预防策略和干预措施。
