One of the features of Balcan endemic nephropathy (BEN) is higher frequency of urothelium malignant tumors, primarily of pyelon (Mtp) and urether (Mtu). Jablanica region is known for the presence of endemic, hypoendemic and non-endemic areas with BEN. The aim of our research was to analyze the appearance of MTUi n endemic settlements of Jablanica region with BEN and to see what the relation of tumor frequency between endemic and non-endemic settlements is. The appearance of MTU was analyzed on the basis of operative protocol data of Urology department, The Health Center in Leskovac and Urology Clinic of The Clinical Center in Nis for the period from 1978 to 2002. We collected data about our patiens regarding their sex, age, the place of living and the place of birth. In order to make classification of settlements we used data of the Institute for Nephrology and hemodialysis (INH) in Nis. Data on total number of population living in these settlements were obtained from the official registration data published in 1981 and 1991. The incidence rate was calculated in the sample of 100,000 people.The average annual incidence rate (AAIR) of MTU in endemic settlements for the considered period is 37.82 (tumors of urether and pyelon - 17.56; malignant tumors of urinary bladder (MTUB 20.26); in hypoendemic settlements the rate is 13.28 (MTp and Mtu - 5.06; MTUB - 8.22); and in non-endemic urban settlements it is 7.35 (Mtu and MTp - 1.04, MTUB - 6.31).AAIR of MTU in endemic areas is 2.85 times higher when compared to hypoendemic areas; it is 6.75 times higher than in non-endemic urban areas, and 5.15 times higher than the rate of non-endemic rural areas. Mtu and MTp are 18.68 times more frequent in endemic settlements than in non-endemic urban areas and 3.47 times more frequent when compared to hypoendemic settlements. The linear trend of the diseased from MTp and MTu in endemic areas of Jablanica region for 25-year period was slowly decreasing according to statistics (y= -0.0054x + 0.59; r2=0.0031.High frequency of Mtu, primarily of Mtu and MTp in areas with BEN, probably points to the common nephropathogenic and cancerogenic etiologic factor, confirming thus the existence of positive correlation between BEN and malignant tumors of upper urothelium (MTUU)
