Brain metastasis is a common cause of death in HER2-positive breast cancer patients. Currently, it is mainly treated by whole-brain radiotherapy. Pyrotinib is an irreversible pan-ErbB inhibitor, which has demonstrated promising tumor-suppressing activity and acceptable tolerance in previous phase trials. In the present study, we evaluated the efficacy of pyrotinib on HER2-positive brain metastatic breast cancer patients treated with whole-brain radiotherapy. A total of 20 such patients were separated into pyrotinib plus capecitabine and capecitabine-only groups in a 1:1 ratio. All patients met either the primary or secondary endpoints. Oral admission of pyrotinib together with radiotherapy can significantly increase the overall response rate, progression-free survival, time to progression and duration of response of HER2+ brain metastatic breast cancer patients, without causing extra adverse events. In addition, pyrotinib can enhance the radiosensitivity of in-vitro cultured HER2+ breast cancer cell lines. The outcome of our study suggests that pyrotinib might be an effective medication to enhance the tumor radiosensitivity of HER2-positive brain metastatic breast cancer patients.

中文翻译：

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吡咯替尼治疗可增强 HER2 阳性脑转移性乳腺癌患者的放射敏感性。

脑转移是 HER2 阳性乳腺癌患者的常见死亡原因。目前主要采用全脑放射治疗。吡咯替尼是一种不可逆的泛 ErbB 抑制剂，在前期试验中已表现出良好的肿瘤抑制活性和可接受的耐受性。在本研究中，我们评估了吡咯替尼对接受全脑放疗的 HER2 阳性脑转移性乳腺癌患者的疗效。总共 20 名此类患者按 1:1 的比例分为吡咯替尼加卡培他滨组和仅卡培他滨组。所有患者均达到主要或次要终点。口服吡咯替尼联合放疗可显着提高HER2+脑转移性乳腺癌患者的总体缓解率、无进展生存期、进展时间和缓解持续时间，且不会引起额外的不良事件。此外，吡咯替尼还可以增强体外培养的HER2+乳腺癌细胞系的放射敏感性。我们的研究结果表明，吡咯替尼可能是增强 HER2 阳性脑转移性乳腺癌患者肿瘤放射敏感性的有效药物。