The role of N-nitrosamine in carcinogenesis at the ureterocolic anastomosis.

Seven cases of colonic tumours occurring at the ureterocolic anastomosis (UCA) in patients diverted for benign disease are presented and comparisons made with existing literature. There appears to be a definite increase in the incidence of colonic malignancy in patients with this diversion. A theory of carcinogenesis involving bacterial activation of endogenously formed N-nitrosamine is suggested. Preliminary results of rectal urine analysis support this theory in that high concentrations of N-nitrosamine have been found mutagens demonstrated.