Comparison of lobe-specific mediastinal lymphadenectomy versus systematic mediastinal lymphadenectomy for clinical stage T1aN0M0 non-small cell lung cancer

Objective: This study was to explore the appropriate extent of mediastinal lymph node dissection for clinical stage T1aN0M0 non-small cell lung cancer (NSCLC) by comparison between two modes of mediastinal lymph node dissection. Materials and Methods: A total of 96 clinical stage T1aN0M0 NSCLC cases received radical surgery were randomly divided to lobe-specific mediastinal lymphadenectomy (LL) group and systematic mediastinal lymphadenectomy (SL) group from the year 2004 to 2008. The effects of SL and LL on morbidity, N staging, overall survival (OS) and disease-free survival (DFS) were investigated. Meanwhile, associations between clinicopathological parameters and metastasis of lymph nodes were analyzed. Results: The mean operating time and blood loss in LL group were significantly less than that in the SL group (135.48 +/- 25.44 min vs. 180.85 +/- 39.36 min, 155.11 +/- 25.17 ml vs. 161.32 +/- 28.20 ml, P < 0.05), the mean numbers of dissected lymph nodes of the SL group was significantly greater than that in the LL group (17.1 +/- 3.7 vs. 9.4 +/- 2.1, P < 0.05). The post-operative overall morbidity rate was higher in the SL group than that in the LL group (P < 0.05). There were no significant difference in migration of N staging, OS and DFS between two groups. The post-operative N staging, the tumor cells differentiation and the ratio of ground glass opacity (GGO) in tumor were the independent factors influencing long-term survival. Moreover, the significant correlation was seen between the metastasis of lymph nodes and clinicopathological parameters including tumor location and the GGO ratio. Conclusion: The LL group had similar efficacy as the SL group in the clinical stage T1aN0M0 NSCLC and there was unnecessary to perform systematic lymphadenectomy in such patients with a high ratio of GGO.