Kong Xiang-Lei, Lu Xi-Wei, Dong Si-Qi, Liu Jiao, Zheng Lei, Chen Lan-Lan, An Zi-Hui, Gao Li-Ming, Cao Jun-Li
Department of Oncology, The First Hospital of Qinhuangdao, Qinhuangdao 066000, Hebei Province, China.
Department of Orthopedics, The First Hospital of Qinhuangdao, Qinhuangdao 066000, Hebei Province, China.
World J Gastrointest Oncol. 2025 Jun 15;17(6):107568. doi: 10.4251/wjgo.v17.i6.107568.
Descending duodenal adenocarcinoma (DDA) is a rare malignancy of the digestive system, typically characterized by microsatellite instability-high (MSI-H). Pembrolizumab is a monoclonal antibody that has been approved for the treatment of MSI-H solid tumors in China.
We present the case of a 55-year-old female patient diagnosed with DDA. Biopsy findings indicated MSI-H status with high expression of programmed cell death-ligand 1 (PD-L1). The patient was unable to undergo immediate surgery due to multiple metastatic lymph nodes in the retroperitoneum. After one cycle of the SOX (S-1 + oxaliplatin) chemotherapy regimen, the patient's performance status significantly declined, and she experienced active gastrointestinal bleeding. Following active communication with the patient's family, pembrolizumab treatment was initiated. After two cycles of treatment, the disease was assessed as a partial response. A positron emission tomography/computed tomography scan performed after two years of treatment indicated a clinical complete response (CCR). The patient maintained this CCR for four years. She has now discontinued pembrolizumab for over one year, and no disease recurrence has been observed during re-examination.
Patients with MSI-H DDA exhibiting high PD-L1 expression who are treated with pembrolizumab can achieve sustained CCR.
降部十二指肠腺癌（DDA）是一种罕见的消化系统恶性肿瘤，通常特征为微卫星高度不稳定（MSI-H）。帕博利珠单抗是一种单克隆抗体，在中国已被批准用于治疗MSI-H实体瘤。
我们报告一例55岁女性患者，诊断为DDA。活检结果显示为MSI-H状态，程序性细胞死亡配体1（PD-L1）高表达。由于腹膜后多发转移淋巴结，患者无法立即接受手术。在接受SOX（S-1+奥沙利铂）化疗方案一个周期后，患者的体能状态显著下降，并出现活动性消化道出血。在与患者家属积极沟通后，开始使用帕博利珠单抗治疗。经过两个周期的治疗，疾病评估为部分缓解。治疗两年后进行的正电子发射断层扫描/计算机断层扫描显示临床完全缓解（CCR）。患者维持这种CCR状态达四年。她现在已停用帕博利珠单抗超过一年，复查期间未观察到疾病复发。
接受帕博利珠单抗治疗的MSI-H DDA且PD-L1高表达的患者可实现持续的CCR。
