Trends in oral cavity cancer incidence, mortality, survival and treatment in the Netherlands.

Information on epidemiology is essential to evaluate care for the growing group of oral cancer patients. We investigated trends in incidence, mortality and relative survival rates for oral cavity cancer (OCC) and its subsites in the Netherlands from 1991 to 2010, and relate these to changes in stage and treatment. Patient (age, sex), tumour (subsite, stage) and treatment characteristics of patients diagnosed with OCC (ICD-O-3: C02-C06) in 1991-2010 were extracted from the Netherlands Cancer Registry. Incidence, mortality and 5-year relative survival rates over time are presented, as well as trends in type of treatment. The incidence of OCC increased with +1.2% (95%CI: +0.9%;+1.6%) per year: more strongly in women, stage I and IV disease, and in cancers of the tongue and gum. The mortality rate slightly rose (+0.8%, 95%CI: +0.3%;+1.3% per year), but differed by subsite. The 5-year relative survival improved from 57% in 1991-1995 to 62% in 2006-2010. The 5-year relative survival was better for women compared with men (64% and 55%, respectively), decreased with increasing stage, was the best for tongue cancer (63%) and the worst for cancer of the gum (56%) and floor of mouth cancer (55%). The relative excess risk of dying was higher for non-surgery-based treatments. Surgery was the main treatment option and the proportion of "surgery only" rose in stage I and III disease. The incidence and, to a lesser extent, mortality of OCC are increasing and therefore, even with slightly improving survival rates, OCC is an increasingly important health problem.