AFP and neoplasm: Correlation analysis showed that AFP was associated with Borrmann type (P = 0.010); CEA with sex (P = 0.029), tumors site (P = 0.014), and N stage (P = 0.001); CA19-9 with age (P = 0.047), tumor site (P = 0.011), lymphovascular invasion (P = 0.004), and N stage (P = 0.000); CA50 with age (P = 0.017), tumor site (P = 0.004), tumor size (P = 0.014), and N stage (P = 0.000).