Case Report
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Aug 6, 2022; 10(22): 7968-7972
Published online Aug 6, 2022. doi: 10.12998/wjcc.v10.i22.7968
Early detection of circulating tumor DNA and successful treatment with osimertinib in thr790met-positive leptomeningeal metastatic lung cancer: A case report
Li-Qing Xu, Ying-Jin Wang, Sheng-Li Shen, Yao Wu, Hong-Zhou Duan
Li-Qing Xu, Ying-Jin Wang, Sheng-Li Shen, Yao Wu, Hong-Zhou Duan, Department of Neurosurgery, Peking University First Hospital, Beijing 100034, China
Author contributions: Xu LQ conceived the article; Xu LQ and Wang YJ collected the data; Wang YJ assembled the data; Xu LQ, Wang YJ, Shen SL, Wu Y and Duan HZ provided the study materials, write the manuscript and approved the manuscript.
Informed consent statement: Informed written consent was obtained from the patient for publication of this report and any accompanying images in October 20, 2021.
Conflict-of-interest statement: All authors declare that they have no conflict of interest to disclose.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Hong-Zhou Duan, Doctor, PhD, Chief Doctor, Department of Neurosurgery, Peking University First Hospital, No. 8 Xishiku Street, Xicheng District, Beijing 100034, China. duanhongzhou@126.com
Received: February 11, 2022
Peer-review started: February 11, 2022
First decision: May 30, 2022
Revised: June 2, 2022
Accepted: June 21, 2022
Article in press: June 21, 2022
Published online: August 6, 2022
Abstract
BACKGROUND

Patients diagnosed with non-small-cell lung cancer with activated epidermal growth factor receptor mutations are more likely to develop leptomeningeal (LM) metastasis than other types of lung cancers and have a poor prognosis. Early diagnosis and effective treatment of leptomeningeal carcinoma can improve the prognosis.

CASE SUMMARY

A 55-year-old female with a progressive headache and vomiting for one month was admitted to Peking University First Hospital. She was diagnosed with lung adenocarcinoma with osseous metastasis 10 months prior to admittance. epidermal growth factor receptor (EGFR) mutation was detected by genomic examination, so she was first treated with gefitinib for 10 months before acquiring resistance. Cell-free cerebrospinal fluid (CSF) circulating tumor DNA detection by next-generation sequencing was conducted and indicated the EGFR-Thr790Met mutation, while biopsy and cytology from the patient’s CSF and the first enhanced cranial magnetic resonance imaging (MRI) showed no positive findings. A month later, the enhanced MRI showed linear leptomeningeal enhancement, and the cytology and biochemical examination in CSF remained negative. Therefore, osimertinib (80 mg/d) was initiated as a second-line treatment, resulting in a good response within a month.

CONCLUSION

This report suggests clinical benefit of osimertinib in LM patients with positive detection of the EGFR-Thr790Met mutation in CSF and proposes that the positive findings of CSF circulating tumor DNA as a liquid biopsy technology based on the detection of cancer-associated gene mutations may appear earlier than the imaging and CSF findings and may thus be helpful for therapy. Moreover, the routine screening of chest CT with the novel coronavirus may provide unexpected benefits.

Keywords: Non-small cell lung cancer, Epidermal growth factor receptor mutation, Circulating tumor DNA detection, Leptomeningeal carcinomatosis, Osimertinib, Case report

Core Tip: Examination of circulating tumor DNA in cell-free cell-free cerebrospinal fluid (CSF) has been shown to be useful for detecting the genomic mutations of tumors in the central nervous system, and osimertinib is considered to be a recent standardized treatment for epidermal growth factor receptor (EGFR) Thr790Met-mutant non-small-cell lung cancer (NSCLC). Hence, we report a patient with EGFR Thr790Met-mutant NSCLC with meningeal carcinomatosis and resistance to gefitinib and propose that the positive findings of CSF circulating tumor DNA as a liquid biopsy technology based on the detection of cancer-associated gene mutations that may appear earlier than the imaging and CSF findings and thus be helpful for therapy.