Etiology of bladder cancer - Facts and speculation

A carcinogenicity in the human bladder has been proven for the aromatic amines benzidine, 4-aminobiphenyl, 2-naphthylamine and 4-chlor-o-toluidine, the alkylating agent cyclophosphamide as well as the analgetic drug phenacetin. Inorganic arsenic is suspected to induce bladder cancer in humans whereas endogenously synthesized nitrosamines may play a role in the etiology of bladder neoplasms due to urinary tract infections and bilharziosis. Kidney-transplant patients with end-stage analgetic nephropathy have a high risk of developing urothelial carcinomas. 25% to 50% of all bladder cancers seem to be associated with smoking. Carcinogenic aromatic amines are known contents of cigarette smoke and could be responsible for the increased risk of bladder cancer among smokers. Epidemiologic studies have shown no evidence of an association between bladder tumors and abnormalities in tryptophan metabolism as well as artificial sweeteners or coffee.