Lung Adenocarcinoma with EGFR Exon 20 H773_V774delinsLM Mutation Sensitive to Furmonertinib: A Case Report

TL;DR

This case report describes a rare EGFR mutation in lung cancer that responded well to a specific targeted therapy.

Contribution

The first reported case of a lung adenocarcinoma with the H773_V774delinsLM EGFR mutation responding to furmonertinib.

Findings

The patient with the H773_V774delinsLM EGFR mutation showed significant tumor shrinkage after treatment with furmonertinib.

This case suggests that furmonertinib may be an effective treatment for this rare EGFR mutation in lung adenocarcinoma.

Abstract

表皮生长因子受体（epidermal growth factor receptor, EGFR）20号外显子突变是非小细胞肺癌中的罕见突变，其中H773_V774delinsLM复杂突变尤为罕见，仅占所有EGFR突变的0.2%-1%。EGFR罕见突变通常被认为对第一、二代EGFR-酪氨酸激酶抑制剂（EGFR-tyrosine kinase inhibitors, EGFR-TKIs）耐药，尽管第三代EGFR-TKIs在部分罕见突变中显示出一定疗效，但针对H773_V774delinsLM突变患者的治疗数据仍十分有限，其疗效和安全性尚未明确。本文报告了首例经伏美替尼治疗后获得显著肿瘤消退的EGFR H773_V774delinsLM突变肺腺癌，以期为临床中这类罕见突变患者可能的治疗方案提供新的见解。

A, B: Treatment naive (A: PET/CT; B: chest CT, mediastinal window); C, D: After four cycles of chemotherapy plus immunotherapy (C: lung window; D: mediastinal window); E, F: At the time of disease progression after immunotherapy (E: lung window; F: mediastinal window); G, H: Prior to targeted therapy (G: lung window; H: mediastinal window); I, J: One month after targeted therapy (I: lung window; J: mediastinal window). PET/CT: positron emission tomography/computed tomography.

A: Prior to second-line therapy; B: Prior to targeted therapy; C: One month after targeted therapy; D: Four months after targeted therapy.

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