Cervical cancer incidence in Denmark over six decades (1943-2002)

Introduction. The purpose of the study was to describe developments in the incidence of invasive cervical cancer in Denmark, focusing on histological types, over a period of 60 years. We also describe developments in the incidence of carcinoma in situ and mortality. Material and methods. The study is based on the Danish Cancer Registry database of 39,623 reported cases of invasive cervical cancer diagnosed among Danish women in the period 1943 - 2002. The most important variables and measures are age-specific and age-standardized incidence and estimated annual percent changes in incidence. Results. A significant reduction in incidence of invasive squamous cell carcinoma among women over 30 during the last 35 years and in incidence of invasive adenocarcinoma among women over 40 during the last 15 years has been seen. In both histological subgroups the relative estimated annual percent change in incidence was largest in the period 1988 - 2002 as compared to 1968 - 1987, coinciding with an increase in the number of Danish women covered by the organized screening program. Women 20 - 29 years old showed a relatively stable squamous cell carcinoma incidence but an increasing adenocarcinoma incidence throughout the study period. Conclusions. These results suggest that the increasing coverage of the Danish organized screening program is associated with a significant reduction in incidence of invasive squamous cell carcinoma among women over 30, and of invasive adenocarcinoma among women over 40. So far, squamous cell carcinoma incidence and adenocarcinoma incidence among women 20 - 29 years old seem quite unaffected by the organized screening program.