Conditional relative survival in head and neck squamous cell carcinoma: Permanent excess mortality risk for long-term survivors.

BACKGROUND Dynamic predictions on head and neck cancer survival could offer, besides improved patient counseling, insight into long-term effects of tumor- and patient-based characteristics on survival. Theoretically, there could be a certain time period after diagnosis after which the patient returns to a population risk on survival. METHODS In all, 7255 patients with a primary head and neck squamous cell carcinoma (HNSCC) aged 25 to 90 years, diagnosed between January 1980 and January 2004 in The Netherlands, were included. Conditional 5-year relative survival for every additional year survived was computed. RESULTS The overall conditional relative prognosis reached a plateau after approximately 4 years; a permanent 20% to 25% excess mortality for long-term HNSCC survivors remained. CONCLUSIONS Conditional 5-year relative survival for patients with HNSCC remains poorer compared to age- and sex-matched counterparts in the general population, even when alive at 15 years after diagnosis. We assume that this is caused by an excess comorbidity in these patients, mainly due to smoking and alcohol abuse.