The role of the registry in the study of relation between cancer and environment experiences from Slovakia.

Highly complete and detailed data on cancer incidence collected in National Cancer Registry of Slovakia in the years 1968-1988 contributed largely to the study of the relations between cancer occurrence and environment. The study of temporal trends of age-adjusted rates revealed the rapid increase of overall cancer incidence and mortality rates in males influenced mainly by extreme increase and high proportion of lung cancer. The lower but increasing overall incidence rates in females could be related to the increase in breast, other skin and genital organs cancers, while the stabilized mortality trends were caused by improving prognosis of these major cancers in females. The possible role of environmental factors in adults could be stressed also by the temporal trends of childhood malignancies which remained fairly stable during the same period. The role of environmental factors in cancer etiology is further documented with the dramatically increasing incidence of malignant skin melanoma caused probably by the overexposition to the sunlight and with prevailing incidence of the majority of cancer sites in urban areas. Finally, the significantly increased incidence rates of other skin cancers are shown in two districts and in both sexes in relation to the environment, highly polluted with arsenic.