Occupational cancer in Denmark. Cancer incidence in the 1970 census population

Abstract

Data sources and creation of data files. The cohort of persons who were 20-64 years of age at the time of the 1970 census has been followed for cancer incidence for a ten-year period. The study was made by linkage of individual records from the 1970 census, the Central Population Register, death certificates, and cancer registrations. Data were included on individual characteristics recorded in the census on prevalent cancer cases at the time of the census and on deaths, emigrations, and incident cancer cases during the ten-year follow-up period. The study includes a total of 2.8 million persons, of whom 2.0 million were economically active at the time of the 1970 census. A total of 115,000 incident cancer cases were registered during the follow-up period, and 77,000 of these occurred in persons who were economically active in 1970. The classifications used in the census included 218 codes for occupation and 245 codes for industry. The Cancer Registry data included 639 codes for diagnosis. Cancer incidence by social groups in Denmark. The cancer incidence was tabulated across 32 socioeconomic groups for 43 cancer sites among the men and 45 cancer sites among the women. The study showed an almost twofold difference in the overall cancer incidence between the socioeconomic groups of the men. Self-employed farmers were at low risk (RR 0.68), and unskilled workers in shipping/fishing were at high risk (RR 1.28) when the cancer incidence among all economically active men was used for the comparison. The social pattern in cancer incidence correlated well with the pattern for cancer mortality among men. As a rough estimate, the cumulative incidence for all cancer among persons under 75 years of age could be reduced by 32% if all Danish men had the cancer incidence of farmers. There was a fivefold or larger difference between the socioeconomic groups in the incidence for nine cancer sites. These nine cancer sites together represented 7% of the cumulative incidence for all cancer. Estimated in a similar way, the cumulative incidence could be reduced by 44% if all Danish men had the site-specific cancer incidence of the respective low-risk groups. The overall cancer incidence among the women varied from a relative risk of 0.71 for unskilled workers in agriculture to a relative risk of 1.18 for self-employed women in other industries I (dentists, lawyers, etc) when the cancer incidence among all economically active women was used for the comparison.(ABSTRACT TRUNCATED AT 400 WORDS)