Radical systematic mediastinal lymphadenectomy versus mediastinal lymph node sampling in patients with clinical stage IA and pathological stage T1 non-small cell lung cancer.

Objective: To explore the appropriate method of mediastinal lymph node dissection for selected clinical stage IA (cIA) non-small cell lung cancer (NSCLC).

Methods: From 1998 through 2002, the curative-intent surgery was performed to 105 patients with cIA NSCLC who had been postoperatively identified as pathologic-stage T1. According to the method of intraoperative medistinal lymph node dissection, they were divided into radical systematic mediastinal lymphadenectomy (LA) group (n = 42) and mediastinal lymph-node sampling (LS) group (n = 63). The effects of LS and LA on morbidity, N staging, overall survival (OS) and disease-free survival (DFS) were investigated. Also, associations between clinicopathological parameters and survival were analyzed.

Results: The mean numbers of dissected lymph nodes per patient in the LA group was significantly greater than that in the LS group (15.59 +/- 3.08 vs. 6.46 +/- 2.21, P < 0.001), and the postoperative overall morbidity rate was higher in the LA group than that in the LS group (26.2 vs. 11.1%, P = 0.045). There were no significant difference in migration of N staging, OS and DFS between two groups. However, for patients with lesions between 2 and 3 cm, the 5-year OS in LA group was significantly higher than that in LS group (81.6 vs. 55.8%, P = 0.041), and the 5-year DFS was also higher (77.9 vs. 52.5%, P = 0.038). For patients with lesions of 2 cm or less, 5-year OS and DFS were similar in both groups. Multivariate analysis showed that lymph node metastasis was the unique unfavorable prognostic factor (P < 0.001).

Conclusions: After being intraoperatively identified as stage T1, patients with lesions between 2 and 3 cm in cIA NSCLC should be performed with LA to get a potentially better survival, and patients with lesions of 2 cm or less should be performed with LS to decrease invasion.