Comparison of the outcomes of sublobar resection and stereotactic body radiotherapy for stage T1-2N0M0 non-small cell lung cancer with tumor size ≤ 5 cm: a propensity score matching analysis

BACKGROUND: Surgery and stereotactic body radiotherapy (SBRT) are both suitable treatment options for early stage Non-small cell lung cancer (NSCLC), which accounts for the majority of lung cancer. This study compared the outcomes of sublobar resection (SLR) and SBRT in patients with stage T1-2N0M0 NSCLC with tumor size ≤5 cm. METHODS: Patients with T1-2N0M0 lung cancer who underwent SLR or SBRT between January, 2012 and December, 2016 were included in this retrospective study. The survival outcomes and toxicity of the SLR and SBRT cohorts were compared using Kaplan-Meier survival plots. In a second exploratory analysis, propensity score matching (PSM) was applied to reduce selection bias between the two groups of patients. RESULTS: A total of 121 SLR and 109 SBRT cases were included. The average follow-up was 49.4 months. Prior to PSM, the 5-year overall survival (OS) and cancer-specific survival (CSS) rates in the SLR group (82.8% and 89.0%, respectively) were superior to those in the SBRT group (67.0% and 75.3%; P=0.001 and P=0.013, respectively). There were no statistically significant differences in the five-year locoregional control and disease-free survival (DFS) rates between the groups. PSM identified 40 patients from each treatment group who shared similar characteristics. At 5 years, the OS rates in the SLR and SBRT groups were comparable (79.9% vs. 66.5%, respectively; P=0.154). After PSM, the rates of CSS, locoregional control, and DFS were also similar between the groups (P=0.458, 0.369, and 0.698, respectively). In the SBRT group, one patient developed grade 3 radioactive pneumonitis. No grade >3 toxicities or treatment-related deaths occurred in either group. CONCLUSIONS: SBRT may be an alternative option to SLR for patients who cannot tolerate lobectomy because of medical comorbidities and has a similar level of effectiveness.