Disparities in guideline-concordant treatment for non-positive, non-small cell lung cancer following surgery

Objectives: To examine guideline concordance across a national sample and determine the relationship between socioeconomic factors, use of recommended postoperative adjuvant therapy, and outcomes for patients with resected pN1 or pN2 non-small cell lung cancer. Methods: All margin-negative pT1-3 N1-2 Mo non-small cell lung cancers treated with lobectomy or pneumonectomy without induction therapy in the National Cancer Database between 2006 and 2013 were included. Use of guideline-concordant adjuvant treatment, defined as chemotherapy for pN1 disease and chemotherapy with or without radiation for pN2 disease, was examined. Multivariable regression models were developed to determine associations of clinical factors with guideline adherence. Survival was estimated using Kaplan-Meier and Cox proportional hazard analyses. Results: Of 13,462 patients, 10,113 had pN1 disease and 3349 had pN2 disease. Guideline-concordant adjuvant therapy was used in 6844 (67.7%) patients with pN1 disease and 2622 (78.3%) patients with pN2 disease. After multivariable adjustment, insurance status, older age, pneumonectomy, readmission, and longer postoperative stays were associated with lower likelihood of guideline concordance. Conversely, increased education level, later year of diagnosis, and greater nodal stage were associated with greater concordance. Overall, patients treated with guideline-concordant therapy had superior survival (5-year survival: 51.6 vs 36.0%; hazard ratio, 0.66; 95% confidence interval, 0.62-0.70, P < .001). Conclusions: Socioeconomic factors, including insurance status and geographic region, are associated with disparities in use of adjuvant therapy as recommended by National Comprehensive Cancer Network guidelines. These disparities significantly impact patient survival. Future work should focus on improving access to appropriate adjuvant therapies among the under insured and socioeconomically disadvantaged.