[Cancer of the bladder after cystitis due to cyclophosphamide. Apropos of a case].

Since 1960, cyclophosphamide has been widely used in the treatment of solid malignant tumors, certain hematological and systemic diseases and indeed even in renal transplantation. However, while the efficacy of the product is certain, it became rapidly apparent that this molecule had a definite toxicity for urinary endothelium, in particular that of the bladder. This toxicity is due to certain metabolites of the molecule and to the fact that urine stagnates in the bladder reservoir. It is manifested principally by hemorrhagic cystitis which is always difficult to treat and which is sometimes life threatening for the patient. However, cyclophosphamide can also induce malignant bladder tumors with a poor prognosis. Since 1971, 56 cases of bladder cancer due to cyclophosphamide have been published. It is therefore a rare lesion generally manifesting itself by hematuria and sometimes occurring a long time after discontinuation of treatment. At the time of first examination, 2/3 of these tumors were widely infiltrating and despite major surgery (50% of cases required immediate total cystectomy) the prognosis was very poor due to the fact that the bladder cancer added its own degree of gravity to that of the initial disease which justified the introduction of treatment. All the authors who have studied this problem therefore stress the necessity of avoiding cyclophosphamide when another molecule may be effective and especially when it is not a malignant condition which is being considered.