Survival and recurrence rates following SBRT or surgery in medically operable Stage I NSCLC

Objectives: Surgery is the standard of care for early-stage non-small cell lung cancer (NSCLC), with SBRT reserved for patients who are not surgical candidates. We hypothesized overall survival (OS), lung cancer-specific survival (LCSS), progression free survival (PFS), and recurrence rates following SBRT or surgery in medically operable patients with Stage I NSCLC from the Veterans' Health Care System (VAHS) would be equivalent. Materials and methods: Medically operable patients diagnosed with Stage I NSCLC between 2000-2020 from the VAHS, determined by an FEV1 or DLCO > 60 % of predicted and Charlson comorbidity index (CCI) of 0 or 1, treated with SBRT or surgery were identified. SBRT patients were propensity score matched in a 1:1:1 ratio to those undergoing resection (SBRT:lobectomy:sub-lobar resection). OS, LCSS, and PFS and site of recurrence were determined. Results: 103 patients were included in each cohort. With a median follow-up of 7.9 years 5-year OS for all patients was 51 % (95 % CI 46-57 %). After propensity score matching, OS (HR 2.08, 1.59), LCSS (HR 2.28, 1.97), and PFS (1.97, 1.45) were significantly worse with SBRT compared to either lobectomy or sub-lobar resection, respectively, (p < 0.05 for each comparison). Regional recurrence was significantly higher following SBRT (15.5 % vs 6.8 % or 4.9 %; p < 0.05), but there was no significant difference in local (28.2 % vs 21.4 % or 21.4 %; p > 0.05) or distant recurrence (10.7 % vs 9.7 % or 13.6 %; p > 0.05) when compared to lobectomy or sub-lobar resection, respectively. Conclusion: In medically operable patients, OS, LCSS, and PFS following either lobectomy or sub-lobar resection were superior to that for SBRT for Stage I NSCLC, likely due in part to higher regional recurrence following SBRT. This suggests that pulmonary function test results and CCI alone are insufficient to define a cohort of medically operable patients suited for SBRT. These data support strategies to overcome regional recurrences seen with SBRT.