# A Case of Refractory Pulmonary Enteric Adenocarcinoma with EGFR Sensitive Mutation

## TL;DR

This paper reports a challenging case of a rare lung cancer subtype with an EGFR mutation that did not respond to standard treatments.

## Contribution

The study highlights the treatment resistance in EGFR-mutated pulmonary enteric adenocarcinoma despite multiple therapies.

## Key findings

- The patient showed no response to first-, second-, and third-generation EGFR-TKIs.
- Combination therapies with TROP2-ADC, ICIs, and bevacizumab also had limited efficacy.
- The case underscores the need for better treatment strategies for EGFR-mutated PEAC.

## Abstract

肺肠型腺癌（pulmonary enteric adenocarcinoma, PEAC）是非小细胞肺癌（non-small cell lung cancer, NSCLC）的一种特殊亚型，其组织形态学及免疫表型与转移性结直肠腺癌高度相似，发病机制及标准治疗策略尚未明确。本文报道1例伴表皮生长因子受体（epidermal growth factor receptor, EGFR）外显子19缺失突变且程序性细胞死亡配体1（programmed cell death ligand 1, PD-L1）高表达的PEAC患者，先后接受第一代（埃克替尼）、第二代（阿法替尼）及第三代（阿美替尼）EGFR-酪氨酸激酶抑制剂（EGFR-tyrosine kinase inhibitors, EGFR-TKIs）治疗均未见明显疗效，滋养层细胞表面抗原2-抗体偶联药物（trophoblast cell surface antigen 2-antibody-drug conjugate, TROP2-ADC）、免疫检查点抑制剂（immune checkpoint inhibitors, ICIs）联合贝伐珠单抗治疗在本例中亦疗效有限。我们基于该病例的临床特征及治疗反应，结合已发表的文献综述了PEAC的病理特征、基因突变谱和治疗现状，重点探讨EGFR突变型PEAC的治疗困境和研究前景，以期为未来临床实践和相关研究提供参考。