Clinical variables and outcomes
tumor, death
BRAIN METASTASIS, TUMOR, LUNG METASTASIS, BONE METASTASIS, LIVER METASTASIS
The clinical variables analyzed in this study include age, race, gender, tumor primary site, tumor size, TNM stage based on the 8th edition of AJCC guidelines, serum CEA level, nerve invasion, lymph node metastasis, liver metastasis, lung metastasis, bone metastasis, and brain metastasis. The primary outcome analyzed was the overall survival (OS), which refers to the time from diagnosis to death from any cause or the end of the follow-up period.