Urbanization gradients and cancer mortality in Uruguay, 1988-1992

Cancer deaths occurring in Uruguay in the period 1988-1992 were classified by site, sex and residence according to the ninth version of the International Classification of Diseases (ICD-9), in order to analyze gradients of urbanization. For this purpose, Uruguayan counties were classified as rural, suburban and urban, using population density as an ordinal indicator of the degree of urbanization. Significant increasing trends with urban excess were observed for cancers of the colon, rectum, lung and female breast. In addition, this study showed significant urban deficits for esophageal, gastric and uterine cancers, contrasting with previous studies. These differences seem to be real rather than artifactual due to misclassification. The study thus provides interesting new findings concerning urban differences between developed communities and a partially developing country.