Stereotactic Body Radiation Therapy Versus Surgery for Early Lung Cancer Among US Veterans

Abstract

Stereotactic body radiation therapy (SBRT) has been proposed as a potential alternative to surgery for early lung cancer, although we lack well-powered prospective randomized data comparing these treatments, and existing studies suffer from incomplete information on confounders that can bias results. Here, we evaluated the comparative effectiveness of surgery and SBRT in lung cancer treatment using a large extensively detailed database from the Veteran's Affairs system. We identified veterans with biopsy-proven clinical stage I non-small cell lung cancer diagnosed between 2006 and 2015 from within the Veteran's Affairs Informatics and Computing Infrastructure. We compared cancer-specific survival among patients receiving lobectomy, sublobar resection, or SBRT using univariable and multivariable competing risk analyses. Multivariable analyses adjusted for confounders including preoperative pulmonary function, smoking status, comorbidity, and staging workup procedures. In all, 4,069 patients were included (449 SBRT, 2,986 lobectomy, 634 sublobar resection). Unadjusted analysis found higher immediate postprocedural mortality in the surgery groups compared with the SBRT group. The multivariable analysis considering long-term survival found higher cancer-specific mortality for SBRT compared with lobectomy (subdistribution hazard ratio 1.45, 95% confidence interval: 1.09 to 1.94, p= 0.01), although no survival difference between SBRT and sublobar resection (subdistribution hazard ratio 1.25, 95% confidence interval: 0.93 to 1.68, p= 0.15). Among a large cohort of early stage lung cancer patients, we found that lobectomy had improved survival compared with SBRT, although we found no survival difference between sublobar resection and SBRT. Despite these findings, the potential for unmeasured confounding remains and prospective randomized trials are needed to better compare these treatment modalities.