Graboyes EM, et al. – This study delineated the effects of National Comprehensive Cancer Network (NCCN) guideline–adherent initiation of postoperative radiation therapy (PORT) and different time–to–PORT intervals on the overall survival (OS) of patients with head and neck squamous cell carcinoma (HNSCC). A link was observed between nonadherence to NCCN guidelines for initiating PORT within 6 weeks of surgery and decreased survival. No survival benefit to initiating PORT earlier within the recommended 6–week timeframe was noted.

Methods

• For the period of 2006-2014, the National Cancer Data Base was reviewed.
• This study determined patients with HNSCC undergoing surgery and PORT.
• In order to ascertain the effects of initiating PORT within 6 weeks of surgery and different time-to-PORT intervals on survival, Kaplan-Meier survival estimates, Cox regression analysis, and propensity score matching were used.

Results

• 41,291 patients were part of this study.
• Starting PORT >6 weeks postoperatively was associated with decreased OS (adjusted hazard ratio [aHR], 1.13; 99% confidence interval [CI], 1.08-1.19), after adjustments for covariates.
• Moreover, this finding remained in the propensity score–matched subset (hazard ratio, 1.21; 99% CI, 1.15-1.28).
• Initiating PORT earlier was not associated with improved survival (aHR for≤4 weeks, 0.93; 99% CI, 0.85-1.02; aHR for 4-5 weeks, 0.92; 99% CI, 0.84-1.01), as compared to starting PORT 5 to 6 weeks postoperatively.
• An association was observed between increasing durations of delay beyond 7 weeks and small, progressive survival decrements (aHR, 1.09, 1.10, and 1.12 for 7-8, 8-10, and >10 weeks, respectively).