Purpose: To evaluate the overall and cause-specific survival in patients with Stage III-IVb head and neck squamous cell carcinoma treated with radiotherapy (RT) as the primary local treatment modality.
Methods and materials: The survival of patients with American Joint Committee on Cancer Stage III-IVb head and neck squamous cell carcinoma treated with primary RT was queried using the Surveillance, Epidemiology and End Results database. The effect of the year of treatment on overall and cause-specific survival was analyzed as a categorical and continuous variable. The patterns of care for these patients were also evaluated.
Results: Between 1988 and 2004, 6,759 patients were identified. Survival was significantly improved in patients treated more recently. When analyzed as a continuous variable, each year was associated with a 3% and 4.1% reduction in the relative risk of overall and cause-specific mortality, respectively (p < 0.0001). Patients treated after 1998 had a 7.6% and 6.1% absolute improvement in overall and cause-specific survival, respectively, compared with patients treated before 1998 (overall survival, hazard ratio, 0.81; cause-specific survival, hazard ratio, 0.77; p < 0.0001). This benefit in survival was limited to tumors of the oral cavity, oropharynx, and hypopharynx. The use of RT increased among patients treated more recently. This shift in patterns of care was most pronounced for tumors of the larynx and hypopharynx.
Conclusions: The overall and cause-specific survival of patients with Stage III-IVb head and neck squamous cell carcinoma treated with primary RT has improved with time. The improvement is consistent with that observed in a large meta-analysis of randomized patients treated with concurrent chemoradiotherapy.