Surgery versus stereotactic body radiotherapy for clinical stage I non-small-cell lung cancer: propensity score-matching analysis including the ratio of ground glass nodules

Purpose To investigate whether surgery and stereotactic body radiotherapy (SBRT) yield comparable outcomes for clinical stage (c-stage) I non-small-cell lung cancer (NSCLC), propensity score-matching (PSM) analysis was conducted. Methods This single-institutional retrospective study included patients who underwent surgery (n = 574) or SBRT (n = 182) between 2004 and 2014. PSM was performed based on tumor diameter, age, sex, performance status, forced expiratory volume, Charlson comorbidity index, and ground glass nodules (GGN) defined as cTis or cT1mi according to the 8th TNM classification. Results The median follow-up durations for the surgery and SBRT groups were 66 and 69 months, respectively. The multivariate analysis revealed that non-GGN was a significant factor for poorer overall survival (OS) and disease-free survival (DFS): hazard ratio (HR) 19.95% confidence interval (CI) 4.7-79,P < 0.001; and HR 28, 95% CI 6.9-110,P < 0.001, respectively. PSM identified 120 patients from each group. The 5-year OS and DFS rates of the surgery vs SBRT groups were 71% (95% CI 61-79) vs 64% (95% CI 54-72) (P = 0.41) and 63% (95% CI 53-72) vs 55% (95% CI 45-63) (P = 0.23) after PSM, respectively. Conclusion The PSM analyses including the ratio of GGN demonstrated that the OS and DFS for patients with c-stage I NSCLC in the surgery group were slightly superior to those for those in the SBRT group, although both survivals were not significantly different between the two therapeutic approaches.