A 20-year retrospective study of tonsil cancer incidence and survival trends in South East England: 1987-2006.

Background: There has been an increasing incidence of tonsil cancer worldwide. Documenting these changes is crucial to cancer prevention and control measures, resource allocation and understanding disease aetiology. Objective: To analyse the changing epidemiology of tonsil cancer in South East England over a 20-year period between 1987 and 2006. Design: A retrospective, quantitative study using secondary anonymised data obtained from the Thames Cancer Registry, London. Data were analysed using spss v.17 and survival analyses with Kaplan-Meier and Cox regression. Setting: This study was conducted in South East of England comprising London, Kent, Surrey and Sussex counties with an average population of 12 million. This population increased from 10.7 to 11.8 million (a 10% increase) between 1987 and 2006. Participants: All patients with tonsil cancer in South East England registered with the Thames Cancer Registry (ICD-10 code C09) between 1987 and 2006. A total of 1794 patients' data were analysed. Ethical Considerations: Ethical approval was granted by the Kent Research Ethics Committee. Main outcome measures: Data were analysed for demographic trends including gender, age at diagnosis, yearly incidence and survival. Results: Tonsil cancer incidence has increased significantly from 0.60 to 1.45 per 100000 in the 20years (P<0.001). This increase is mainly amongst men and age groups 40-59years with a significant reduction in age at diagnosis by 2years from 61.6years in the first decade to 59.6years in the second decade (P<0.001). Survival was worse in men, older age groups and in the presence of synchronous tumours (P<0.001). There has been a statistically significant increase in median survival times from tonsil cancer by about 3years from 2.7years in the first decade to 5.7years in the second decade of this study (P<0.001). Conclusions: Tonsil cancer incidence has increased in the 20years of this study in South East England, especially amongst men and age groups 40-59years. There has also been significant reduction in the mean age at diagnosis and an increase in median survival times for tonsil cancer. Further studies are needed to explain these trends.