Potential Benefit of Effective Implementation of Timely Postoperative Radiation for Head and Neck Cancer

OBJECTIVE: This study aimed to investigate the potential benefit of survival of receiving timely postoperative radiation therapy (PORT) for head and neck cancer. STUDY DESIGN: Retrospective cohort. SETTING: National Cancer Database from 2004 to 2020. METHODS: Patients with a diagnosis of human papilloma virus (HPV)-negative head and neck squamous cell carcinoma who received adjuvant radiation were included. Exposure groups included timely PORT or delayed PORT (≤42 or >42 days from surgery to radiotherapy, respectively). The primary outcome was 5-year overall survival (OS). Inverse probability weighted models were used to estimate OS in the counter-factual scenario that all patients started radiation within 6 weeks while adjusting for confounding. Observed OS was for the entire cohort, while predicted OS was for the generated model of universal timely PORT within 6 weeks. Survival analyses were replicated for demographic and clinical subgroups. RESULTS: In total, 58,184 patients were included. Patients were mostly male, white, and non-Hispanic. The observed average 5-year OS was similar to the predicted OS (observed 0.58, 95% CI: 0.57-0.578; predicted 0.58, 95% CI: 0.57-0.59). The largest predicted benefit for timely PORT was seen in privately insured, white, rural, males, and with hypopharyngeal and stage IV cancer, though confidence intervals included the null hypothesis. Conversely, black patients were predicted to have a decline in OS with timely PORT (observed 0.54, 95% CI 0.53-0.56; predicted 0.50, 95% CI 0.46-0.52). CONCLUSION: For the overall cohort and other subgroups, even if optimally implemented, timely PORT is not predicted to improve OS. Modeling outcomes can guide resource allocation to the most impactful interventions.