Evaluation of Quality Metrics for Surgically Treated Laryngeal Squamous Cell Carcinoma.

Importance: Quality metrics for patients with laryngeal squamous cell carcinoma (SCC) exist, but whether compliance with these metrics correlates with improved survival is unknown. Objective: To examine whether compliance with proposed quality metrics is associated with improved survival in patients with laryngeal SCC treated with surgery with or without adjuvant therapy. Design, Setting, and Participants: This retrospective cohort study included patients from a tertiary care academic medical center who had previously untreated laryngeal SCC and underwent surgery with or without adjuvant therapy from January 1, 2003, through December 31, 2012. Data analysis was performed from August 4, 2015, through December 13, 2015. Interventions: Surgery with or without adjuvant therapy. Main Outcomes and Measures: Compliance with quality metrics from the American Head and Neck Society (AHNS), National Comprehensive Cancer Network (NCCN) guidelines, and institutional metrics with face validity covering pretreatment evaluation, treatment, and posttreatment surveillance was evaluated. The association between compliance with the group of metrics and overall survival (OS), disease-specific survival (DSS), and disease-free survival (DFS) was explored using Cox proportional hazards analysis. The association between compliance with individual metrics and survival was similarly determined.
Results: A total of 243 patients (184 men and 59 women) were included in the study (median age, 62 years; age range, 23-87 years). No association was found between increasing levels of compliance with the AHNS or NCCN metrics and survival. The only AHNS or NCCN metric for which greater compliance correlated with improved survival on multivariable Cox proportional hazards analysis controlling for pT stage, pN stage, extracapsular spread, margin status, and comorbidity was pretreatment multidisciplinary evaluation for patients with stage cT3-4 or cN1-3 disease (OS adjusted hazard ratio [aHR], 0.47; 95% CI, 0.24-0.94; DFS aHR, 0.45; 95% CI, 0.23-0.85). For the institutional metrics, multidisciplinary evaluation for all patients (OS aHR, 0.51; 95% CI, 0.29-0.88; DFS aHR, 0.50, 95% CI, 0.32-0.80) and elective neck dissection yield of 18 lymph nodes or more (DFS aHR, 0.36; 95% CI, 0.14-0.99) were associated with improved survival on multivariable Cox proportional hazards analysis. Conclusions and Relevance: In this cohort of patients with surgically treated laryngeal SCC, multidisciplinary evaluation and elective neck dissection yield of 18 lymph nodes or more are associated with improved survival. Development of better quality metrics is necessary because increased compliance with metrics described by the AHNS and NCCN is not associated with improved survival. Previously described metrics for surgically treated oral cavity cancer are not prognostic for surgically treated laryngeal SCC. Future multi-institutional collaboration will be required to validate these findings, develop better quality metrics, and evaluate whether quality metrics for head and neck cancer are site specific.