It was found that only positive EGFR mutations (P = .012), positive ALK gene fusion (P = .015), and positive RET gene fusion (P = .003) were independent risk factors for brain metastasis, and that a young age, lymph node metastasis, and histological type (adenocarcinoma) were also independent risk factors for brain metastasis. This evidence concerns the gene RET and metastatic malignant neoplasm in the lymph nodes.