Relative and absolute cancer mortality of women in agriculture in northern Italy

Abstract

Most studies of cancer risk related to agricultural exposures have focused on male operators. Cancer mortality in a cohort of 38 962 women engaged in agriculture (Province of Forlì, 1969-1993) was compared with that of the rest of the female residents using the ratio of age-standardized (Europe) mortality rates (ASR) with 95% confidence interval (CI). Moreover, mortality time trends in both subsets of the population were evaluated. The cohort yielded 798 439 person-years with 2397 cancer deaths. Total ASR ratio was 0.86 (95% CI 0.80-0.92). Only gastric cancer was associated with a significant but declining excess mortality (ASR ratio 1.26; 95% CI 1.11-1.43). Total ASR ratio decreased from 1.07 (95% CI 0.95-1.20) in 1969-1976 to 0.74 (95% CI 0.66-0.82) in 1985-1993. This resulted from a downward mortality trend restricted to the cohort. In particular, mortality from cancers of the oesophagus, stomach and colon/rectum decreased more steeply in the cohort. Mortality from liver cancer decreased only in the cohort. Mortality from cancers of the pancreas, lung, breast, bladder and skin melanoma remained stable in the cohort whilst increasing in the rest of the population. In conclusion, risk excesses previously reported were not confirmed. Agricultural workers qualified as a subset of the female population with atypical, favourable epidemiologic characteristics.