Delaying postoperative radiation therapy past 6 weeks lowers survival in head and neck squamous cell carcinoma
Initiating postoperative radiation therapy later than 6 weeks after surgery appeared associated with decreased survival in patients with head and neck cancer, according to findings published in Cancer.
“The only measure of timely care incorporated into NCCN guidelines for patients with head and neck squamous cell carcinoma is the time interval between surgery and postoperative radiation therapy, for which the ‘preferred interval between resection and postoperative [radiation therapy] is ≤ 6 weeks,’” Evan M. Graboyes, MD, of the Medical University of South Carolina, Charleston, and colleagues wrote. “Delays in initiating adjuvant therapy and care not adherent to NCCN guidelines are nevertheless common. The oncologic effect of NCCN guideline-adherent care for timely adjuvant therapy remains uncertain.”
The researchers reviewed the National Cancer Data Base for patients with head and neck squamous cell carcinoma who underwent surgery and postoperative radiation therapy between 2006 and 2014 (n = 41,291). Graboyes and colleagues used Kaplan-Meier survival estimates, propensity score matching and Cox regression analysis to evaluate possible effects of the timing of postoperative radiation therapy.
Starting postoperative radiation therapy more than 6 weeks after surgery appeared associated with decreased OS (adjusted HR = 1.13; 99% CI, 1.08-1.19). This held true in a propensity score-matched subset of patients (HR = 1.21; 99% CI, 1.15-1.28).
However, compared with starting radiation therapy 5 to 6 weeks after therapy, beginning adjuvant treatment earlier did not appear associated with improved survival (HR = 0.93; 99% CI, 0.85-1.02 for starting therapy at ≤4 weeks; HR = 0.92; 99% CI, 0.84-1.01 for 4 to 5 weeks). Each increasing delay after 7 weeks was associated with “small, progressive” decrements in survival (HR = 1.09 for 7 to 8 weeks; 1.10 for 8 to 10 weeks; 1.12 for >10 weeks), according to the researchers.
“Care not adherent to NCCN guidelines for initiating postoperative radiation therapy within 6 weeks of surgery is associated with decreased survival,” the researchers wrote. “There is no OS benefit to initiation postoperative radiation therapy earlier within the recommended 6-week timeframe. Increasing durations of delay beyond 7 weeks are associated with small, progressive survival decrements.” – by Andy Polhamus
Disclosures: The researchers report no relevant financial disclosures.