Surgical Outcomes for Early-Stage Non-Small Cell Lung Cancer at Facilities With Stereotactic Body Radiation Therapy Programs

Abstract

<h3>Purpose/Objective(s)</h3> Patients undergoing surgery for early-stage non-small cell lung cancer (NSCLC) may be at high-risk for post-operative mortality. Access to stereotactic body radiation therapy (SBRT), a less invasive alternative, may facilitate more appropriate patient selection for surgery. <h3>Materials/Methods</h3> An analysis of all patients with early-stage NSCLC reported to the National Cancer Database between 2004-2015 was performed. Post-operative mortality rates were derived using vital status data. Utilization of SBRT was defined by each facility's SBRT Experience in years and SBRT-to-Surgery Volume Ratios, defined by quartiles. Multivariable logistic regression with backward elimination was used to test for the associations between facility-level SBRT utilization and post-operative mortality. Interaction testing of independent covariates was performed to assess the effect of SBRT utilization across subgroups. <h3>Results</h3> The study cohort consisted of 202,542 patients who underwent surgical resection of clinical stage T1-T2 N0 M0 NSCLC between 2004-2015. The 90-day post-operative mortality rate declined significantly during the study period from 4.6% to 2.6% (p < 0.001). During this period, the proportion of facilities that utilized SBRT increased from 4.6% to 77.5% (p < 0.001) and the proportion of patients treated with SBRT increased significantly from 0.7% to 15.4% (p < 0.001). On multivariable analysis, lower 90-day post-operative mortality rates were observed among patients who underwent resection at facilities with greater than six years of SBRT Experience (OR 0.84, CI 0.76-0.94, p = 0.003) and SBRT-to-Surgery Volume Ratios above 17% (OR 0.85, CI 0.79-0.92, p < 0.001). Additional covariates associated with 90-day mortality included higher surgical volume, geographic region, year of diagnosis, age, sex, race, insurance status, facility type, Charlson-Deyo score, clinical T stage, histology, anatomic location, surgery type, and prior malignancy. Interaction testing between these covariates was negative, demonstrating that findings were consistent across subgroups. <h3>Conclusion</h3> Patients who underwent surgical resection for early-stage NSCLC at facilities with higher SBRT Experience and SBRT-to-Surgery Volume Ratios had lower rates of post-operative mortality. These findings suggest that the availability of SBRT may improve allocation of patients to surgery or SBRT, particularly for higher-risk patients. The observation of higher post-operative mortality rates at facilities without an SBRT program merits further investigation.