Background: The clinical value of postoperative radiotherapy (PORT) in stage N2 nonsmall-cell lung cancer (NSCLC) is controversy. The aim of this study is to analyze the efficacy of PORT in subgroup of stage N2 NSCLC, which can help clinicians to choose proper patients for PORT.
Methods: Clinical data of 359 patients with stage N2 NSCLC treated with radical surgery between Mar. 2000 and Jul. 2005 were retrospectively reviewed. Two hundred and seven patients received adjuvant chemotherapy and one hundred and four patients received adjuvant radiotherapy. First, the group of patients were analyzed to evaluate the factors affecting the overall survival. The all patients were divided based on tumor size and the number of lymph node metastasis station (single station or multiple station) so as to evaluate the role of PORT. The endpoint was overall survival (OS) and local recurrence-free survival (LRFS). Kaplan-Meier method was used to calculate the OS, LRFS and Log-rank was used to compare the difference in OS and LRFS between different groups.
Results: The median duration of follow-up was 2.3 years. 224 patients died. The median survival was 1.5 years and 1, 3, 5-year survival were 78%, 38% and 26%. Univariate analysis showed tumor size, the number of lymph node metastasis station and PORT were correlated with OS. Among patients, 5-year survival rates in PORT and non-PORT were 29% and 24% (P=0.047) respectively. In subgroups, PORT was related with high survival in patients with multiple station N2 compared to non-PORT: 36% vs 20% (P=0.013) and 33% vs 15% (P=0.002) in patients in patients with tumor size>3 cm. Also, it was related with low local recurrence compared to non-PORT: 65% vs 48% (P=0.006) and 62% vs 48% (P=0.033).
Conclusions: PORT can improve overall survival for N2 NSCLC, especially the patients with the factors as follows: tumor size>3 cm and multiple station N2 can benefit from PORT more or less.