VIP and metastatic malignant neoplasm in the lymph nodes: Multivariate analysis of the factors potentially associated with lymph node metastasis (age, sex, smoking history, tumor location, tumor diameter, visceral pleural involvement, pathologic subtype, and serum CEA concentration) showed that tumor diameter, VIP, pathologic subtype, and high serum CEA concentration predicted lymph node metastasis (P < .05) (Table 2).