Background: Trastuzumab deruxtecan (T-DXd) has shown promising outcomes as a second or subsequent-line treatment for human epidermal growth factor-2 (HER2)-positive advanced gastric or gastroesophageal junction cancer. Case Presentation: We reported a 49-year-old male patient with stage IV HER2-amplified gastric cancer. Despite extensive pretreatments, including first-line trastuzumab plus FOLFOX, second-- line trastuzumab plus FOLFOX, followed by traditional Chinese medicine, third-line nivolumab plus trastuzumab, fourth-line pyrotinib plus paclitaxel and five hepatic arterial chemoembolization procedures, and fifth-line pembrolizumab plus nab-paclitaxel and thoracic radiotherapy, the patient experienced disease progression. In April 2021, T-DXd was initiated as the sixth-line therapy in combination with radiotherapy for brain metastases. After one treatment cycle, the patient achieved a partial response. T-DXd was discontinued in August 2022 due to recurrent anemia attributed to cardiac stenosis-related bleeding. Conclusion:: The condition of the patient remained stable until May 2023, indicating a progression- free survival of over 24 months. This case suggests that T-DXd may offer long-term clinical benefits in patients with HER2-amplified advanced gastric cancer with brain metastases. Conclusion: The condition of the patient remained stable until May 2023, indicating a progression-free survival of over 24 months. This case suggests that T-DXd may offer long-term clinical benefits in patients with HER2-amplified advanced gastric cancer with brain metastases.

中文翻译：

---

HER2 扩增晚期胃癌脑转移患者接受曲妥珠单抗 Deruxtecan 治疗后 24 个月无进展生存：病例报告和文献综述

背景：曲妥珠单抗 deruxtecan (T-DXd) 作为人表皮生长因子 2 (HER2) 阳性晚期胃癌或胃食管交界癌的二线或后续治疗显示出有希望的结果。病例介绍：我们报告了一名 49 岁男性患者，患有 IV 期 HER2 扩增胃癌。尽管进行了广泛的预处理，包括一线曲妥珠单抗+ FOLFOX、二线曲妥珠单抗+ FOLFOX，然后是中药、三线纳武单抗+曲妥珠单抗、四线吡咯替尼+紫杉醇和五次肝动脉化疗栓塞术，以及五线派姆单抗加白蛋白结合型紫杉醇和胸部放疗后，患者出现了疾病进展。2021年4月，T-DXd作为脑转移瘤联合放疗的六线疗法启动。一个治疗周期后，患者获得部分缓解。由于心脏狭窄相关出血导致复发性贫血，T-DXd 于 2022 年 8 月停用。结论：：直到 2023 年 5 月，患者病情一直保持稳定，表明无进展生存期超过 24 个月。该病例表明，T-DXd 可能为 HER2 扩增的晚期胃癌脑转移患者提供长期临床益处。结论：直至2023年5月，患者病情保持稳定，无进展生存期超过24个月。该病例表明，T-DXd 可能为 HER2 扩增的晚期胃癌脑转移患者提供长期临床益处。