TRENDS IN NONEPITHELIAL CANCER INCIDENCE IN DENMARK, FINLAND AND SWEDEN, 1961-1990

Trends in the incidence of non-epithelial cancers are particularly lik ely to reflect environmental carcinogens, since these malignancies are not commonly the targets of screening efforts, and have generally not been closely associated with life style factors such as cigarette smo king and diet. We used data from nation-wide cancer registries in Denm ark, Finland, and Sweden to examine trends in non-epithelial cancers o ver the period 1961-1990. Linear regression analysis of age-standardiz ed rates, and age-period-cohort models were fit to assess the temporal patterns within each country. Within each of the 3 countries, there w as a similarly increasing incidence of both hematological malignancies and nervous system/bone/soft-tissue neoplasms. The increases were sma llest in children and adolescents (ages 0-14), moderate among young an d middle aged adults (ages 15-64), and most pronounced among the elder ly (ages 65+). Age-period-cohort modeling suggested that the dominant factor in the increases were birth cohort effects. It is not clear wha t factors underlie this increase in incidence; it seems most likely th at increases both in diagnostic efficiency and in exposure to environm ental carcinogens play a role. (C) 1996 Wiley-Liss, Inc.