Incidence of tumors of urinary organs in a focus of Balkan endemic nephropathy.

A prospective follow-up study which included a 25% sample of the population of Petka, a hyperendemic village located in the vicinity of Belgrade, was conducted over a 15 year period (1974 to 1988). The cohort consisted of 416 members who made up the denominator of 5,723 person-years of observation. Incidence of deaths, either from or with tumors of urinary organs, was taken as a measure of outcome. The diagnosis of tumor was based on pathohistological confirmation. Incidence density of urinary tract tumors was 1.75 per 1,000 person-years. Six individuals had upper urothelial tumors (incidence density = 1.40 per 1000 person-years of observation). These tumors occurred in 32% of the cases who had Balkan endemic nephropathy.