Survival outcome after stereotactic body radiation therapy and surgery for stage I non-small cell lung cancer: a meta-analysis

Purpose: This study compared treatment outcomes of stereotactic body radiation therapy (SBRT) with those of surgery in stage I non-small cell lung cancer (NSCLC).

Methods and materials: Eligible studies of SBRT and surgery were retrieved through extensive searches of the PubMed, Medline, Embase, and Cochrane library databases from 2000 to 2012. Original English publications of stage I NSCLC with adequate sample sizes and adequate SBRT doses were included. A multivariate random effects model was used to perform a meta-analysis to compare survival between treatments while adjusting for differences in patient characteristics.

Results: Forty SBRT studies (4850 patients) and 23 surgery studies (7071 patients) published in the same period were eligible. The median age and follow-up duration were 74 years and 28.0 months for SBRT patients and 66 years and 37 months for surgery patients, respectively. The mean unadjusted overall survival rates at 1, 3, and 5 years with SBRT were 83.4%, 56.6%, and 41.2% compared to 92.5%, 77.9%, and 66.1% with lobectomy and 93.2%, 80.7%, and 71.7% with limited lung resections. In SBRT studies, overall survival improved with increasing proportion of operable patients. After we adjusted for proportion of operable patients and age, SBRT and surgery had similar estimated overall and disease-free survival.

Conclusions: Patients treated with SBRT differ substantially from patients treated with surgery in age and operability. After adjustment for these differences, OS and DFS do not differ significantly between SBRT and surgery in patients with operable stage I NSCLC. A randomized prospective trial is warranted to compare the efficacy of SBRT and surgery.