[Importance of segmental lymph nodes in the pathological staging of non-small cell lung cancer]

Objective: To explore the role of the segmental lymph node dissection in the pathologic staging of non-small cell lung cancer. Methods: A total of 370 consecutive non-small cell lung cancer patients who underwent radical resection between August 2008 and July 2016 were retrospectively reviewed. All the operations were performed by the same group of surgeons. The relationship of the segmental lymph nodes with pathological stages after radical resection was analyzed in order to explore the role of the lymph node dissection in the pathologic staging of non-small cell lung cancer (using the 7th edition of the American Joint Committee on Cancer and Union for International Cancer Control TNM classification for lung cancer ). Results: The detection rates of hilar nodes, interlobar nodes, lobar nodes and segmental nodes were 69.7%, 86.8%, 84.0%, 67.0%, respectively. The metastasis rates of hilar nodes, interlobar nodes, lobar nodes and segmental nodes were 6.5%, 10.8%, 15.7% and 10.3%, respectively. There were 238 cases of N0 disease, 62 cases of N1 disease, 69 cases of N2 disease and 1 case of N3 disease. If the analysis of segmental lymph nodes had been omitted, 16 patients (25.8% of N1 disease) would have been down-staged to N0, and 5 cases of multiple-station N1 disease would have been misdiagnosed as single-station N1 disease, 2 patients would have been misdiagnosed as N2 disease with skip metastases. Conclusion: Segmental nodes play an important role in the accurate staging of non-small cell lung cancer.