Impact of different mediastinal lymphadenectomy on clinical-stage IA non-small cell lung cancer

Abstract

To study the role of different lymphadenectomy in the treatment of selected clinical-stage IA non-small cell lung cancer. All 115 postoperative patients admitted from January 1997 to May 2002 with pathologic-stage T1 who had been preoperatively diagnosed as clinical-stage I A non-small cell lung cancer were divided into a radical systematic mediastinal lymphadenectomy (LA) group and a mediastinal lymph node sampling (LS) group. Impacts on morbidity, N staging, overall survival (OS) and disease-free survival (DFS) were evaluated in each group respectively. Associations between clinical-pathological parameters (age, sex, tumor location, tumor size, pathological type and lymph node metastases) and OS, DFS were analyzed. The cumulative OS and DFS was calculated by the Kaplan-Meier method and compared by the Log-rank test. The mean number of dissected lymph nodes was (15.98 +/- 3.05) in LA group and (6.48 +/- 2.16) in LS group with a significant difference (P < 0.01). No statistically significant difference existed in modification of N staging, OS and DFS between LA group and LS group. However, for patients with lesions of a diameter more than 2 cm, 5-year OS in LA group was significantly higher than that in LS groups (LA vs. LS = 78.2% vs. 54.5% ,P < 0.05), also 5-year DFS was significantly higher (LA vs. LS = 75.1% vs. 51.3%, P < 0.05). For patients with lesions of 2 cm or less, 5-year OS and 5-year DFS were similar in both groups. The early surgery-related parameters (duration of surgery, drain secretion and morbidity) indicated a slighter invasion in LS group. In addition, patients with large cell carcinoma and adenosquamous carcinoma were associated with significantly poor 5-year OS (P < 0.05) , and patients with lymph node metastases were associated with poor 5-year OS as well as 5-year DFS (P < 0.01). After being intraoperatively identified as T1 stage, patients with lesions of more than 2 cm in clinical-stage IA non-small cell lung cancer should be performed with LA to get a better survival, and patients with lesions of 2 cm or less should be performed with LS to decrease invasion.