CEACAM5 and metastatic malignant neoplasm in the lymph nodes: Smoking (OR 2.633; 95% CI 1.093–6.345; P = 0.031), pathotypes (taking SCLC as reference, TC, OR 0.139, 95% CI 0.028–0.688, P = 0.016; AC, OR 0.105, 95% CI 0.031–0.353, P = 0.000), and pretreatment CEA (> 5 ng/ml, OR 3.084; 95% CI 1.256–7.572; P = 0.014) were proved to be the independent factors of lymph-node metastasis.