Abstract:

Objective To analyze the clinical characteristics of lung adenocarcinoma patients with positive EGFR mutations detected in pleural effusion. Methods We retrospectively analyzed the clinical characteristics including gender， age， smoking history， presence of other underlying diseases （such as COPD， cardiovascular disease， and diabetes）， site of pleural fluid， feature of pleural fluid， and TNM stage in patients with lung adenocarcinoma who had been admitted to the first Affiliated Hospital of Bengbu Medical College from 2020.01 to 2022.12 for the first time by the detection of EGFR mutation positive in pleural effusion. The data were statistically analyzed using the SPSS 26.0 software. Results A total of 126 patients were screened for enrollment， including 61 patients （48.41%） with EGFR exon 19 deletion mutation （19del）， 56 patients （44.44%） with exon 21 L858R mutation （21L858R）， and 9 patients （7.14%） with non?classical mutations. Univariate analysis showed that the three mutation subtypes were statistically significant in terms of gender， age， smoking history， and presence of COPD （P < 0.05 for all comparisons）， but not in terms of pleural fluid site， feature of pleural fluid， tumor size， and presence of cardiovascular disease， diabetes mellitus， presence of distant metastases， and mediastinal lymph node metastases （P > 0.05 for all comparisons）； Multivariate analysis showed that 21 L858R mutation was more likely to be found in male， older age， non?smoking， and presence of COPD than 19del mutation； non?classical mutation was more likely to be found in male than 19del mutation. Conclusions There are significant differences among the three mutation subtypes in sex， age， smoking history， and presence of COPD， but not in pleural fluid location， feature of pleural fluid， tumor size， presence of cardiovascular disease or diabetes mellitus， presence of distant metastases， or mediastinal lymph node metastases； Among lung adenocarcinoma patients with positive EGFR mutations in pleural fluid， 21 L858R mutation mostly occurs in male， older age， non?smokers， and those complicated with COPD， while non?classical mutation mainly develops in male. However， more case studies are needed to confirm the above conclusions.

Key words: EGFR mutation?positive, pleural effusion, lung adenocarcinoma, clinical features