Molecular and epidemiological approaches to the etiology of urinary tract tumors in an area with Balkan endemic nephropathy.

Recently, we completed a second biostatistical study of urinary tract tumors (UTT) in areas with Balkan endemic nephropathy (BEN) in the Vratza district, Bulgaria, during the period 1975 to 1991. We confirmed the positive correlation between the incidence of urinary tract tumors (UTT) and BEN demonstrated in our first population-based case control 1977 study. A UTT incidence of 98.