Survival benefit of post-operative chemotherapy for intermediate-risk advanced stage head and neck cancer differs with patient age

Abstract

Objectives: The National Comprehensive Cancer Network (NCCN) guidelines state that surgical patients with advanced-stage head and neck cancer (HNC) and risk factors other than extranodal extension (ENE) or positive margins should consider post-operative chemoradiation (POCRT). The goal of our study was to determine if POCRT is associated with overall survival (OS) compared with post-operative radiation therapy (PORT) and whether this varies with patient age.

Material and methods: We conducted a retrospective study of 5319 adult patients with stage III-IV HNC who received primary surgical treatment with POCRT or PORT in the National Cancer Database (2010-2013). Patients with distant metastases, ENE, and positive margins were excluded. Intermediate risk features included pT3-T4, pN2-N3 disease, and lymphovascular invasion. Our main outcome was overall survival (OS). Statistical analysis included chi-squared tests and Cox proportional hazards regressions.

Results: On multivariable analysis for non-oropharyngeal cancer patients <70 years, POCRT was associated with improved OS for T1-4N2-3 disease (hazard ratio [HR], 0.73, 95% confidence interval [CI]; 0.58-0.93) but was not associated with OS for T3-4N0-1 disease (HR, 0.92; 95% CI, 0.71-1.19). For patients ≥70 years, POCRT was not associated with improved OS for patients with T1-4N2-3 disease (HR, 1.21; 95% CI, 0.79-1.86) or T3-4N0-1 disease (HR, 1.08; 95% CI, 0.71-1.65). For oropharyngeal cancer patients with HPV-positive disease, POCRT was associated with decreased OS (HR, 9.52; 95% CI, 2.38-38.08).

Conclusion: Chemoradiation may offer a survival benefit for non-oropharyngeal intermediate-risk advanced-stage HNC patients <70 years of age with T1-4N2-3 disease, but may not benefit those ≥70 years of age or those with T3-4N0-1 disease.

Keywords: Chemoradiation; Chemotherapy; Head and neck cancer; Hypopharyngeal cancer; Laryngeal cancer; Oral cancer; Oral cavity cancer; Oropharyngeal cancer; Post-operative; Radiation therapy.