Does an extended mediastinal lymphadenectomy improve outcome after R0 resection in lung cancer?

This retrospective study was conducted to investigate the impact of more extended mediastinal lymphadenectomy on the outcome of lung cancer patients treated with R0 resection.

During the investigation period, 325 lung cancer cases were enlisted and 278 cases entered the analysis. The patients were divided into Control group (n=116) and Research group (n=162) according to the different extents of mediastinal lymph node clearance at different time periods. Three major parameters were retrospectively assessed to compare the quality of surgical care: extent of lymph node clearance, resection volume, and postoperative recovery process and common complications. Comparison of the outcome between two groups was carried out.

Research group showed a significant quality improvement of lymphadenectomy, such as more mediastinal node stations investigated (more than 3 N2 stations investigated: Research group, 90.7% vs. Control group, 55.2%; P=0.001) and more nodes collection (total nodes 26.1±10.0 vs. 19.1±8.3, P=0.000; N2 nodes 15.5±7.2 vs. 9.8±5.6, P=0.000). However, overall survival (OS) and disease-free survival (DFS) were not significantly different either between two groups (5-year OS: Control group, 56.4±4.6% vs. Research group, 62.6±4.3%; P=0.271) or between subgroups from stage I to IIIa. TNM stage and histology were significant factors associated with OS and DFS in multivariate analysis; extent of mediastinal lymphadenectomy was not associated with OS or DFS.

More radical mediastinal lymphadenectomy may not lead to an improved oncological outcome for lung cancer treated with R0 resection.