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. 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 five-fold 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. Both the men and the women in agriculture thus had a low risk of cancer. There was, however, a difference between the men and the women at the high-risk end of the scale, as self-employed and well-educated women were among the groups of women with a relatively high cancer incidence. These groups of women had an excess risk of breast cancer and of other skin cancers, whereas unskilled women had an excess risk of lung cancer. The cumulative incidence for all cancer among persons under 75 years of age could, with a rough estimate, be reduced by 25-28% if all women were under the cancer risk recorded for women in agriculture. The cancer incidence was tabulated across 492 detailed occupational groups for 43 cancer sites among the men and across 447 detailed occupational groups for 45 cancer sites among the women. The validity of the linked register was assessed through the inspection of the data on classic associations between occupational exposures and cancer sites. The register showed an excess risk of lip cancer among farmers and fishermen, an excess risk of primary liver cancer among waiters and brewerey workers, an excess risk of pleural mesothelioma among occupations with potential exposure to asbestos, and an excess risk of nasal cancer among furniture makers. The use of the linked register as a library for the further elucidation of associations between occupations and cancers reported in the literature was illustrated throught the use of examples. An excess risk of bladder cancer among hairdressers found in Geneva was also found in Denmark. A suspected risk of malignant melanoma among lithographers could not be found in Denmark. Leukemia was not elevated among the majority of farmers in Denmark, but there was an indication of an excess risk for a subgroup of farms. An excess risk of brain tumors was been observed among dentists and dental nurses in Sweden, but this observation could not be confirmed in Denmark.
|Tidsskrift||Scandinavian Journal of Work, Environment and Health|
|Udgave nummer||SUPPL. 2|
|Status||Udgivet - 11 okt. 1990|