Systematic lymph node dissection is necessary for T1a non-small cell lung cancer

AimWith the development of computed tomography, the number of surgical interventions for small-sized lung cancer has increased. It still remains controversial whether a systematic lymph node dissection is necessary in such cases. MethodsFrom 2004 to 2010, a total of 138 patients with non-small cell lung cancer (NSCLC) of 2cm or less in diameter were operated on in our institution. The clinical data were retrospectively analyzed using the Kaplan-Meier method and compared using the log-rank test in surgical approaches, lymph node involvement, histology and survival rates. ResultsLymph node metastasis was found in 24 of 138 (17%) patients. The 5-year survival rate for patients without lymph node metastasis was 83%, whereas it was 75 and 48% for those with pN1 and pN2 disease (P=0.001). Patients receiving lobectomy had a significantly better survival rate than patients receiving limited resection (P=0.02). The 5-year survival rates for patients with stage I, stage II and stage III were 90, 78 and 43%, respectively (P<0.001). Lymph node metastasis was found in 1 of 11 (9%) patients with tumors sized less than 1cm, 7 of 39 (18%) patients with tumors sized from 1.1 to 1.5cm, and 16 of 64 (25%) patients with a tumor larger than 1.5cm (statistically not significant). ConclusionThe survival of patients with small-sized lung cancer is closely related to the nodal involvement, stage of disease and surgical approaches. Our study supports that systematic lymph node dissection should be performed in patients with T1a NSCLC.