Background: In patients with
lung adenocarcinoma and leptomeningeal
metastases, it remains unknown whether non-classical mutations in the
epidermal growth factor receptor (EGFR) gene can be detected in the cerebrospinal fluid (CSF) and how it may be used to design directed
therapy. Methods: On April 18, 2018, the Interventional Department of Tianjin Huanhu Hospital admitted a 34-years-old male patient with
lung adenocarcinoma and leptomeningeal
metastasis. An emergency lateral
ventriculoperitoneal shunt was performed to relieve the clinical symptoms of
intracranial hypertension. Next-generation sequencing (NGS) of the CFS specimens revealed a mutation in EGFR exon 18 p.G719A, and
afatinib was administered. Follow-up showed significantly relieved
headache, with significantly reduced soft leptomeningeal abnormal enhancement as revealed by enhanced magnetic resonance imaging and significantly smaller
tumors in the left lung by chest computed tomography. Carcinoembryonic
antigens (CEAs) in cerebrospinal fluid and peripheral blood were significantly reduced. The patient responded well to
afatinib, with mild adverse complications. The patient died on October 27, 2019 from
respiratory failure as a result of lung
infection unrelated to
cancer progression. The overall survival (OS) using
afatinib was 530 days. Conclusion: CSF can be used as a liquid biopsy for NGS gene detection in patients with
lung adenocarcinoma and leptomeningeal
metastases.
Afatinib exhibits a beneficial effect in patients with
lung adenocarcinoma and leptomeningeal
metastases harboring the EGFR exon 18 p.G719A mutation.