Therefore, in the present study, -216G/T genotyping and immunohistochemical detection of EGFR protein expression was performed in two cohorts of patients with primary lung adenocarcinoma and pleural metastasis respectively, with the aim of determining the association between -216G/T variants in the EGFR gene and the risk of the pleural metastasis of lung adenocarcinoma. Here, EGFR is linked to lung adenocarcinoma.