Objectives: Delays in the initiation of postoperative radiation have been associated with worse outcomes; however, the effect of the overall treatment package time (interval from surgery through the completion of radiation) remains undefined. The purpose of this study was to determine the impact of package time on survival and to evaluate this effect among different subgroups of head and neck cancer patients.
Patients and methods: In this observational cohort study, the National Cancer Database was used to identify 35,167 patients with resected nonmetastatic head and neck cancer who underwent adjuvant radiation from 2004 to 2014. Kaplan-Meier survival estimates and multivariate Cox regression analyses were performed to determine the effect of treatment package time on overall survival.
Results: Median package time was 96 days (interquartile range, 85-112 days). After adjusting for covariates, package times of 11 weeks or less were associated with improved survival (adjusted hazard ratio (aHR), 0.90; 95% confidence interval, 0.83-0.97) compared to an interval of 12-13 weeks, whereas package times of more than 14 weeks were associated with worse survival (aHR, 1.14, 1.14, and 1.22 for 14-15, 15-17, and >17 weeks, respectively). A significant interaction was identified between package time and disease site, nodal status, and stage. Specifically, patients with oropharyngeal tumors, advanced stage (III or IV) disease, or nodal involvement experienced more pronounced increases in mortality risk with delays in treatment time.
Conclusions: Treatment package time independently impacts survival. This effect may be strongest for patients with oropharyngeal tumors or advanced stage disease.
Keywords: Head and neck cancer; National Cancer Database; Package time; Postoperative radiation; Squamous cell carcinoma.
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