Abstract:

Objective To compare and analyze the gene mutation of EGFR of bronchoalveolar lavage fluid （BALF） exosome， serum and lung cancer tissue specimens of patients with advanced non?small cell lung cancer （NSCLC） and assess whether the BALF exosome specimens are suitable for screening before clinical targeted therapy， to provide new ideas and screening methods for early individualized treatment of advanced NSCLC patients. Methods BALF exosomes， serum and lung cancer tissue specimens EGFR gene mutations of 78 cases with advanced NSCLC were detected by using amplification refractory mutation system（ARMS） method in Department of Respiratory and Critical Care Medicine in our hospital from May 2021 to May 2023， and the results were retrospectively analyzed. A comparative analysis of the specimens was conducted using lung cancer tissue specimens as benchmarks. Results A total of 33， 25 and 38 cases of EGFR gene mutation and 42， 53 and 40 cases of EGFR wild type were detected in BALF exosomes， serum and lung cancer tissues specimens respectively. The mutation rate of EGFR gene was 42.3%（33/78， 32.1 %（25/78）and 48.7%（38/78）in BALF exosomes， serum and lung cancer tissues specimens respectively. EGFR detection showed no results in 3 cases and the false?negative rate was 6.4% （5/78） in BALF specimen， and false?negative rate was 16.7% （13/78） in serum. The detection coincidence rate of EGFR mutation was 86.8% （33/38） in BALF exosomes specimen， and 65.8% （25/38） in serum. Conclusions EGFR gene mutation rate in BALF exosome specimen is consistent with that in serum and lung cancer tissue samples， showing no statistical significance （P > 0.05）. It is superior to serum specimen and suitable for patient screening before targeted therapy and provides new ideas and screening methods for early individualized treatment decisions of advanced NSCLC patients.

Key words: exosome, EGFR, ARMS, advanced NSCLC, BALF