25 year survival outcomes for squamous cell carcinomas of the head and neck: population-based outcomes from a Canadian province.

OBJECTIVES: Long term outcomes of patients with head and neck cancer (HNC) are rarely reported, but of potential benefit to clinicians and researchers. Squamous cell carcinomas (SCC) of the head and neck represent a heterogeneous group of cancers. The purpose of this population based study is to describe primary site specific, long term outcomes of HNC.

METHODS: All patients from a Canadian province diagnosed between 1986 and 1990 with SCC of the oral cavity, pharynx, and larynx were identified. Chart review and patient data were abstracted through the provincial cancer registry database. Survival analysis was performed with Kaplan Meier methods, while differences in survival between groups were assessed with log-rank tests. Multivariable analysis was performed using Cox-regression.

RESULTS: 1657 patients were analyzed during the study period. Almost half (50.9%) of the cases were advanced stage (stage III IV) at presentation. Two, 5, 15 & 25year overall survival (OS) and HNC specific survival for all the patients were 64%, 46%, 21%, 11% and 74%, 63%, 53% & 49%, respectively. OS and HNC-specific mortality were statistically inferior among men, older age at diagnosis, advanced stages of disease, and was primary cancer site specific, with worse survival in oropharyngeal & hypopharyngeal sites, p<0.001.

CONCLUSIONS: Survival rates vary by primary HNC site, and the overall survival & HNC specific survival differ over this long follow up assessment. Head and neck cancer specific death is most common in the first five years, and is subsequently dominated by competing causes of mortality. These results are useful as a reference tool for clinicians, researchers, and trainees.