Families with multiple cases of urinary system tumors: brief communication.

A study of three families living in villages with endemic nephropathy (EN) in Vratza district, Bulgaria, revealed 9 members with urinary system tumors (UST), 7 with UST and EN, and 7 with EN. Most cases were registered from 1962 to 1976. The predominant form was transitional cell neoplasms of the kidney pelvis and ureter in patients 40-60 years old. In about 40% of the patients more than one site in the urinary system was involved. One ovarian carcinoma was also registered in these families during this period. Persons related by marriage and coming from nonendemic families and villages were also affected by both diseases. In other branches of the three families living in other households or villages, only one case of EN was found.

Familial aggregation of urinary system tumors in a region with endemic nephropathy.

In hyperendemic villages in the Vratza district of Bulgaria, 193 patients with urinary system tumors (UST) were diagnosed during 1965 to 1976. A tendency towards familial aggregation was revealed when the patients were compared with two groups of controls, namely, patients with tumors other than UST and healthy persons. Each control group consisted of 193 persons matched by sex, age, and place of birth. This tendency was observed in all relatives who lived together as well as in those related by blood. The probability of having relatives with UST was 2.5 times higher than could be expected as chance occurrence among UST patients than among the controls. The UST cases also had significantly more relatives with endemic nephropathy than did the controls. The familial clustering of both UST and nephropathy in the endemic region is considered another clue to their common etiology.

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.

LDH isoenzymes in cell cultures from transplantable hamster tumors with dissimilar histogenesis and differentiation.

LDH isoenzymes were assayed by acrylamide disc electrophoresis in the following material: (a) cells from 4 transplantable hamster tumors; (b) cells from the same tumors cultured for 0, 4, 12 or 24 h as well as for 3, 7, 12 or 26 days; (c) tumors obtained after re-inoculation of cells cultured for 26 days. During the first days of culture, the cells retained LDH patterns similar to those of tumors in vivo. Then a progressive increase in the M/H ratio was observed in all cultures. This was followed by a complete disappearance of LDH 1,2,3. In the tumors appearing after re-inoculation of cultured cells, re-emergence of the patterns seen in the original tumors was noted. The mechanism of the observed changes remains hypothetical although an adaptive re-arrangement of gene activity controlling the production of M and H subunits and/or in vitro selection of clones with higher M/H ratio is postulated.

Geographic correlation between the occurrence of endemic nephropathy and urinary tract tumours in vratza district, Bulgaria.

Data on the occurrence of endemic nephropathy (EN) and urinary tract and other cancers in an endemic region of Vratza district, Bulgaria, for the years 1965-1974, are presented. In endemic villages a high incidence of urinary tract tumours, affecting in particular the renal pelvis and ureter, closely correlated with the EN incidence and mortality rates. In the villages with high and moderate EN incidences urinary tract tumours are the most common neoplasms. They account for 25% of all tumour sites in males and 30% in females. In hyperendemic villages age-adjusted incidences in EN and urinary tract tumours were 506/10(5) and 104/10(5) in females, and 315/10(5) and 89/10(5) in males respectively. EN mortality in these villages accounted for over 40% of all deaths in females and about 30% in males. Both diseases displayed peculiar geographic clustering. Females and middle-aged persons were most often affected. Urinary tract neoplasms were often multiple and nearly 90% of them originated in the uro-epithelium. In endemic and non-endemic villages of the region studied, the frequency and pattern of non-urinary tract cancers were rather similar, with statistical values close to those of the rural population of Vratza District and Bulgaria as a whole.