Stereotactic body radiotherapy and treatment at a high volume facility is associated with improved survival in patients with inoperable stage i non-small cell lung cancer

Background This study examined the comparative effectiveness of no treatment (NoTx), conventional fractionated radiotherapy (ConvRT), and stereotactic body radiotherapy (SBRT) in patients with inoperable stage I non-small cell lung cancer. This population based cohort also allowed us to examine what facility level characteristics contributed to improved outcomes. Methods We included patients in the National Cancer Database from 2003 to 2006 with T1-T2N0M0 inoperable lung cancer (n = 13,036). Overall survival (OS) was estimated using Kaplan-Meier methods and Cox proportional hazard regression. Results The median follow up was 68 months (interquartile range: 35-83 months) in surviving patients. Among the cohort, 52% received NoTx, 41% received ConvRT and 6% received SBRT. The 3-year OS was 28% for NoTx, 36% for ConvRT radiotherapy, and 48% for the SBRT cohort (p < 0.0001). On multivariate analysis, the hazard ratio for SBRT and ConvRT were 0.67 and 0.77, respectively, as compared to NoTx (1.0 ref) (p < 0.0001). Patients treated at a high volume facility vs. low volume facility had a hazard ratio of 0.94 vs. 1.0 (p = 0.01). Conclusions Patients with early stage inoperable lung cancer treated with SBRT and at a high volume facility had a survival benefit compared to patients treated with ConvRT or NoTx or to those treated at a low volume facility.