The impact of radiation treatment time on survival in patients with head and neck cancer

Abstract Purpose To assess the impact of radiation treatment time (RTT) in head and neck cancers on overall survival (OS) in the era of chemoradiation. Materials & Methods Patients diagnosed with tongue, hypopharynx, larynx, oropharynx, or tonsil cancer were identified using the National Cancer Database. RTT was defined as date of first radiation treatment to date of last radiation treatment. In the definitive setting, prolonged RTT was defined as >56 days, accelerated RTT was defined as < 47 days, and standard RTT was defined as 48–56 days. In the post-operative setting, prolonged RTT was defined as >49 days, accelerated RTT was defined as < 40 days, and standard RTT was defined as 41-49 days. Chi-squared tests were used to identify predictors of RTT. The Kaplan-Meier method was used to compare OS amongst groups. Cox proportional hazards model was used for OS analysis in patients with known comorbidity status. Results 19,531 patients were included; 12,987 (67%) had a standard RTT, 4,369 (34%) had an accelerated RTT, and 2,165 (11%) had a prolonged RTT. On multivariable analysis, accelerated RTT (HR 0.84 95% CI 0.73-0.97) was associated with an improved OS while prolonged RTT (HR 1.25 95% CI 1.14-1.37) was associated with a worse OS relative to standard RTT. When examining the 9,200 (47%) patients receiving definitive concurrent chemoradiation, prolonged RTT (HR 1.29 95% CI 1.11-1.50) was associated with a worse OS relative to standard RTT while there was no significant association between accelerated RTT and OS (HR 0.76 95% CI 0.57-1.01). Conclusion Prolonged RTT is associated with worse OS in patients receiving radiotherapy for head and neck cancer, even in the setting of chemoradiation. Expeditious completion of radiation should continue to be a quality metric for the management of head and neck malignancies.