BACKGROUNDIntrathoracic lymph node metastasis including hilus and mediastinum is one of important prognosis factors of lung cancer. The aim of this study is to investigate the characteristics and patterns of lymph node metastasis in non-small cell lung cancer and to provide evidence for determining the range of lymph node dissection.

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

RESULTSA total of 1553 lymph nodes were dissected from 155 lung cancer patients. The positive ratios of N1 and N2 were 20.0% (31/155) and 38.7% (60/155) respectively. Fifteen patients (9.7%) were found with skipping N2 which were located in lymph node groups 2, 4, 5, 6 and 7 respectively. There was close correlation between lymph node metastasis and T stage (P < 0.01). The metastatic rate of lymph node in different histology had no significant difference. Skipping mediastinal lymphatic metastasis was found more frequently in lung cancer.

CONCLUSIONSLymph node metastasis of non-small cell lung cancer may occur in multiple groups and regions, even in a skipping pattern. Systematic lymph node dissection may be routinely performed in pulmonary resection for non-small cell lung cancer except stage T1.