Descriptive epidemiology of thyroid cancer in France: incidence, mortality and survival

Describe time trends of incidence and mortality associated with thyroid cancer and provide 1 and 5-year survivals by histological group in French areas covered by cancer registries.

Data for 1975 to 2004 were provided by one thyroid-dedicated and 11 general registries. Incidence estimates were obtained by correction of incidence from areas with registries, then projections for 2008 were derived. Overall and relative survivals by sex and age (diagnosis period 1989-1997; cut-off date 1st January 2002) were obtained from the dedicated and nine other registries. Comparisons between areas or time periods used world-standardized rates.

Between 1980 and 2005, incidence increased but mortality decreased in men and women. Annual cases increased five times and projections for 2008 were 8,000 cases and 400 deaths. The main increasing subtype was papillary carcinoma. One-year overall and relative survivals were 92 and 94%, respectively. Five-year overall and relative survivals were 87 and 93%, respectively. The highest survival (>94%) concerned papillary carcinomas and the lowest (<15%) anaplastic carcinomas. Survivals were generally higher in women than in men; precisely, higher in women for papillary and follicular carcinomas but higher in men for medullary and anaplastic carcinomas. Survivals increased with age, but for medullary carcinomas. Survivals from anaplastic carcinomas were very low whatever the age.

The increase of thyroid cancer frequency is dramatic but survivals are improving. Though the prognosis of the most increasing histological subtype is generally good, it remains very important to identify the causes of this steady increase to implement adequate preventive measures.