Regional differences in smear-taking activity and cervical cancer incidence in Denmark 1943-1982

The cumulative incidence of cervical cancer in women aged 30-59 was studied for regions equivalent to the present counties based on data in the Danish Cancer Registry from the years 1943-82. Trends in the cumulative incidence are related to available data on number of smears taken in and outside the organized screening programmes for cervical cancer. The analysis shows, that the considerable geographic differences observed in cervical cancer in the 1940s have now disappeared and there is today no difference in the incidence of cervical cancer among women aged 30-59 in Copenhagen and in the Western part of Jutland. In 1978-82, however, the incidence for women aged 30-59 in Fyn county was twice the incidence in Frederiksborg county. In the mid 1970s, three times as many smears were taken in Frederiksborg county as in Fyn county. In 1978-82, the incidence for women aged 30-59 was also low in Storstrom county. In the mid 1970s, a considerably lower number of smears were taken in this region than in Frederiksborg county, but the same high proportion of the female population was screened. Based on the analysis, it seems reasonable to conclude that the smear-taking activity has had a considerable influence on the observed decline in the incidence of cervical cancer in Denmark.