The epidemiology of thyroid cancer in Scotland, 1960 - 1999
J Weir1, DH Brewster1 & MWJ Strachan2
Background : The aim of this study was to investigate trends in incidence, mortality and survival for thyroid cancer, in Scotland.
Methods : Thyroid cancer registration data (for the period 1960-1997) were obtained from the Scottish Cancer Registry and death registration data (1960-1999) were provided by the General Register Office, Scotland. Trends were examined using rate calculations and relative survival analysis.
Results : During the period 1960-1997, the age-standardised incidence rate was two to three times higher in females than males, and rose more markedly in females during the 1990s. However, death rates gradually decreased between 1960 and 1999, in both sexes.
Males and females showed different age-related patterns of incidence. Female incidence increased steadily from the early twenties to middle age, then rose more sharply in those aged over 70 years. Male incidence increased steadily from middle age onwards.
Females aged over 70 and diagnosed during the latter stages of the study period had lower age-specific incidence rates than those diagnosed during the earlier years.
Since the mid-1970s, when the collection of information on tumour morphology began, the incidence of papillary thyroid cancer has increased in both sexes, especially since the mid-1980s in females.
Thyroid cancer survival increased for both males and females (patients diagnosed between 1976 and 1995, aged 15-99 years). This improvement in survival was most striking in males diagnosed between 1976 and 1985.
Conclusions: Overall the incidence of thyroid cancer has increased, particularly in females during the 1990s, although death rates have fallen in both sexes over the last three decades. Age-specific incidence differed between the sexes and over the study period. Much of the recent increase has occurred in papillary carcinoma. Since the 1970s, thyroid cancer survival has improved for both sexes.