Prognostic effect of number of lymph nodes sampled in patients with stage Ⅰ non-small cell lung cancer

Objective To investigate the prognostic effect of quantity of lymph node(LN)resected in operations of patients with stage Ⅰ non-small cell lung cancer(NSCLC).Methods The clinical, pathological and follow-up data of 74 patients with stage Ⅰ NSCLC who were treated with surgery from January 1998 to December 2002 Beijing Friendship Hospital, Affiliated to Capital Medical University were reviewed retrospectively.Grouping the patients, according to the quantity of lymph node resected, the Kaplan-Meier method and Cox proportional hazards model was used for univariate analysis and multivariate analysis of factors with prognostic effect.Results The five year survival rate and disease-free survival(DFS)rate of these 74 patients were 64.9% and 47.3%.The univariate analysis showed that tumor size(P =0.016),T-staging (P =0.008)and extent of lymph node dissection(P =0.013)could influence the survival rate.The 5-year OS and DFS rates of patients with less than 6 LNs resected were less than the other group(more than 6 LNs)apparently.The multifactorial analysis indicated that other than staging, the quantity of lymph node resected was also an influence factor of prognosis.Conclusions The OS rate of patients has positive correlation with quantity of lymph node resected in operations.Six LNs must be resected leastways in operations of patients with stage Ⅰ NSCLC.