The impact of stereotactic body radiation therapy on the overall survival of patients diagnosed with early-stage non-small cell lung cancer

Background and purpose: Stereotactic Body Radiotherapy (SBRT) has emerged as a standard treatment for inoperable early-stage non-small cell lung cancer (NSCLC) with remarkable local control. However, it is not clear if this local control translates to overall survival (OS). The objective of this study is to investigate the impact of SBRT on the OS of early-stage NSCLC patients and examine if the extent of this impact changes with the era of diagnosis, T stage, age, and comorbidity status. Materials and methods: Using the National Cancer Database, we compared the OS of cT1–3 cN0 cM0 NSCLC patients with SBRT or observation. Multivariable analyses were adjusted for age, race, sex, income, education, place of living, hospital type, insurance status, comorbidity score, histology types, and diagnosis year. Results: Among 50,819 patients, 27,027 (53.18%) received SBRT and 23,792 (46.82%) were observed. Multivariable Cox Proportional-Hazards analysis demonstrated SBRT was associated with an improved OS compared to observation (HR:0.56, p < 0.001). Subset multivariable Cox Proportional-Hazards analyses stratified by T stage, year of diagnosis, age, or Charlson Score revealed that HRs of SBRT vs. observation decrease from cT1 to cT3 (0.73–0.68), from 2004 to 2015 (0.65–0.51), from <50 to ≥80 years old (1.04–0.58) and from a Charlson Score 0 to 2 (0.69–0.58). Conclusion: SBRT was associated with improved OS compared to no treatment in early-stage NSCLC. The magnitude of the impact of SBRT on OS increases in patients with advanced age, higher T stages, higher comorbidity scores and more recent treatment eras.