Treatment Outcomes in Stage I Lung Cancer: A Comparison of Surgery and Stereotactic Body Radiation Therapy.

INTRODUCTION: The relative roles of surgery and stereotactic body radiation therapy in stage I non-small-cell lung cancer (NSCLC) are evolving particularly for marginally operable patients. Because there is limited prospective comparative data for these treatment modalities, we evaluated their relative use and outcomes at the population level using a national database.
METHODS: Patient variables and treatment-related outcomes were abstracted for patients with clinical stage I NSCLC from the National Cancer Database. Patients receiving surgery were compared with those undergoing stereotactic body radiation therapy (SBRT) in exploratory unmatched and subsequent propensity matched analyses.
RESULTS: Between 1998 and 2010, 117,618 patients underwent surgery or SBRT for clinical stage I NSCLC. Of these, 111,731 (95%) received surgery, whereas 5887 (5%) underwent SBRT. Patients in the surgery group were younger, more likely to be males, and had higher Charlson comorbidity scores. SBRT patients were more likely to have T1 (versus T2) tumors and receive treatment at academic centers. Thirty-day surgical mortality was 2596 of 109,485 (2.4%). Median overall survival favored the surgery group in both unmatched (68.4 versus 33.3 months, p < 0.001) and matched analysis based on patient characteristics (62.3 versus 33.1 months, p < 0.001). Disease-specific survival was unavailable from the data set.
CONCLUSION: In a propensity matched comparison, patients selected for surgery have improved survival compared with SBRT. In the absence of information on cause of death and with limited variables to characterize comorbidity, it is not possible to assess the relative contribution of patient selection or better cancer control toward the improved survival. Rigorous prospective studies are needed to optimize patient selection for SBRT in the high-risk surgical population.