Outcomes of stereotactic body radiotherapy versus lobectomy for stage I non-small cell lung cancer: a propensity score matching analysis

BACKGROUND: Lobectomy is the standard treatment for patients with stage I non-small cell lung cancer (NSCLC). Recent studies have shown promising results of stereotactic body radiation therapy (SBRT) in these patients. We retrospectively compared the outcomes of lobectomy and SBRT in these patients from our therapeutic center. METHODS: Patients who underwent lobectomy or SBRT for clinical T1–2a (T size≤5 cm), N0 M0, NSCLC between December 2011 and August 2016 were reviewed. Patient characteristics, treatment-related outcomes and toxicities were analyzed. Propensity score matching (PSM) was performed to improve comparability between the two groups. RESULTS: Median follow-up period in the lobectomy (n = 246) and SBRT (n = 70) group was 31.4 months and 24.9 months, respectively. Three-year local recurrence-free survival (LRFS) was comparable in the two groups (97% vs. 91.7%, respectively; P = 0.768). Recurrence-free survival (RFS) at 3-year in the lobectomy and SBRT groups was 85.4 and 69.5%, respectively (P = 0.014). Three-year overall survival (OS) after lobectomy and SBRT was 88.2 and 79.7%, respectively (P = 0.027), while 3-year cancer-specific survival (CSS) was 91.3 and 82.5% (P = 0.022). After PSM (45 matched patients in each group), there was no significant between-group difference with respect to 3-year LRFS (89.6% vs. 87.5%, P = 0.635), RFS (77.6% vs. 67.3%, P = 0.446), OS (78.5% vs. 79.5%, P = 0.915) or CSS (86.4 and 79.5%, P = 0.551). In matched subgroup, 30-day mortality after lobectomy was 2.2%, and no treatment-related death occurred after SBRT. CONCLUSIONS: Treatment-related outcomes of SBRT and lobectomy were comparable. SBRT was well tolerated and had a very low toxicity profile in our study. SBRT is a promising alternative treatment option for stage I NSCLC patients. This study indicates that matching these disparate cohorts of patients is challenging. Clinical trials are essential to define the indications and relative efficacy of lobectomy and SBRT in a selected population.