Epidemiologic data for environmental determination of urinary system tumours and nephropathy in an endemic region

One hundred and thirty-eight patients diagnosed for urinary system tumours (UST), 714 patients with endemic nephropathy (EN) and 55 cases of UST and EN combined, all from endemic villages of Vratza district, Bulgaria were investigated for their familial pattern and time of diagnosis compared with the age at diagnosis. There were 144 spouses among these patients and nearly half of them came from non-endemic families and villages. The familial pattern followed the size of the population found to be at greater risk, i.e. people 40-60 years old, in particular women. Among the investigated 91 pairs of parents and children and 166 pairs of siblings the mean diagnostic interval was shorter than the mean difference of age at diagnosis. Therefore the epidemiologic data provide support to the hypothesis that possibly environment plays a predominant role in the familial aggregation and in the etiology of UST and EN in the endemic region.