BACKGROUNDTo investigate the characteristics and patterns of lymph node metastasis in lung cancer, and to provide evidence for determining range of lymph node dissection.

METHODSOne hundred and five patients with lung cancer received complete resection combined with systematic lymph node dissection according to the mapping system developed by Naruke.

RESULTSA total of 801 lymph nodes were dissected from 105 lung cancer patients. The positive ratios of N1 and N2 were 15.9% and 14.9%, respectively. Twelve patients were found with skipping N2. These skipping N2 were located in 2, 4, 5, 6, 7 groups respectively. There was no significant relationship between size of primary tumor and lymph node metastasis. Small cell lung cancer showed the highest risk of lymph node metastasis. The metastatic rate of lymph node in adenocarcinoma was markedly higher than that in squamous cell carcinoma. Skipping mediastinal lymphatic metastasis was found more frequently in lower lobar tumors than that in upper lobar ones.

CONCLUSIONSLymph node metastasis of lung cancer may occur in multiple groups and multiple regions, even in a skipping pattern. Systematic lymph node dissection should be routinely performed in pulmonary resection for lung cancer.