Department of Pulmonary and Critical Care Medicine, The First Affiliated Hospital of Guangxi Medical University, Nanning, China.
Department of Medicine, Geneplus Beijing, Beijing, China.
Front Immunol. 2024 Jan 25;14:1266304. doi: 10.3389/fimmu.2023.1266304. eCollection 2023.
Pulmonary enteric adenocarcinoma (PEAC) is a rare histological subtype of non-small-cell lung cancer (NSCLC) with a predominant (>50%) enteric differentiation component. The frequency of high microsatellite instability (MSI-H) is very low in lung cancer. EGFR tyrosine kinase inhibitors and immunotherapy are standard treatment for NSCLC patients, but their effectiveness in lung adenocarcinoma with pulmonary enteric differentiation is unknown.
This report describes a 66-year-old man who was initially diagnosed with metastatic lung adenocarcinoma with mutation based on pleural fluid. A lung biopsy was obtained after 17 months of first-line icotinib treatment. Histological analysis of biopsy samples and endoscopic examination resulted in a diagnosis of adenocarcinoma with enteric differentiation. Next-generation sequencing of 1,021 genes showed E19del, T790M, and MSI-H, while immunohistochemical assay showed proficient expression of mismatch repair (MMR) proteins. Consequently, the patient was treated with osimertinib and had a progression-free survival (PFS) of 3 months. His treatment was changed to chemotherapy with/without bevacizumab for 6.5 months. Then, the patient was treated with one cycle of camrelizumab monotherapy and camrelizumab plus chemotherapy, respectively. The tumor continued to grow, and the patient suffered pneumonia, pulmonary fungal infections, and increased hemoptysis. He received gefitinib and everolimus and died 2 months later and had an overall survival of 30 months.
In summary, our case describes a rare pulmonary enteric adenocarcinoma with an -activating mutation and MSI-H, responding to an EGFR tyrosine kinase inhibitor and poorly benefiting from an immune checkpoint inhibitor.
肺肠型腺癌（PEAC）是一种罕见的非小细胞肺癌（NSCLC）组织学亚型，具有主要（>50%）肠分化成分。肺癌中高频微卫星不稳定（MSI-H）的频率非常低。表皮生长因子受体酪氨酸激酶抑制剂和免疫疗法是 NSCLC 患者的标准治疗方法，但它们在具有肺肠分化的肺腺癌中的有效性尚不清楚。
本报告描述了一名 66 岁男性，最初根据胸腔积液诊断为转移性肺腺癌，存在 突变。一线伊可替尼治疗 17 个月后，获得了肺活检。活检样本的组织学分析和内镜检查结果诊断为肠型腺癌。1021 个基因的下一代测序显示 E19del、T790M 和 MSI-H，而免疫组化检测显示错配修复（MMR）蛋白表达良好。因此，患者接受奥希替尼治疗，无进展生存期（PFS）为 3 个月。他的治疗方案改为化疗联合/不联合贝伐珠单抗治疗 6.5 个月。随后，患者分别接受了一个周期的卡瑞利珠单抗单药治疗和卡瑞利珠单抗联合化疗。肿瘤持续进展，患者发生肺炎、肺部真菌感染和咯血增加。他接受了吉非替尼和依维莫司治疗，2 个月后死亡，总生存期为 30 个月。
总之，我们的病例描述了一例罕见的肺肠型腺癌，存在 激活突变和 MSI-H，对表皮生长因子受体酪氨酸激酶抑制剂敏感，对免疫检查点抑制剂反应不佳。
