Four‐gene Prognostic Signature and Risk of Brain Metastasis of Lung Adenocarcinoma

Brain metastasis has a high incidence and poor prognosis in lung adenocarcinoma (LUAD). We sought to identify genes associated with LUAD brain metastasis and with the prognosis of patients with LUAD. Differential gene expression analysis was performed on LUAD patients with and without distant metastasis from the Cancer Genome Atlas (TCGA) database and LUAD patients with and without brain metastasis from the GEO GSE14108 and GSE10072 data sets. Subsequently, a LASSO model was constructed using the genes differentially expressed in both analyses to screen for prognostic genes. A risk model based on 11 genes was established by screening prognostic genes. Subsequently, a prognostic prediction model was developed based on the risk model. Expression and survival analysis of the identified genes in metastatic LUAD was assessed. As a result, differential gene expression analysis indicated that compared to primary lung cancer, the expression of CMAS, NEK2, and SHCBP1 was significantly upregulated in metastatic lung cancer, whereas the expression of IL2 was significantly downregulated. Additionally, these genes exhibited strong correlations with the overall survival of LUAD patients. Finally, compared with LUAD patients without brain metastasis, immunohistochemistry analysis verified CMAS, NEK2, and SHCBP1 exhibited increased expression in LUAD with brain metastasis.