INTESTINAL METAPLASIA IS NOT A STRONG RISK FACTOR FOR BLADDER-CANCER - STUDY OF 53 CASES WITH LONG-TERM FOLLOW-UP

Objectives. Intestinal metaplasia often coexists with adenocarcinoma o f the urinary bladder, suggesting to some investigators that it is pre malignant. However, the natural history and long-term outcome of intes tinal metaplasia in isolation are unknown. We report 53 cases of intes tinal metaplasia of the urinary bladder followed for more than 10 year s. Methods. We reviewed the Mayo Clinic surgical pathology files betwe en 1926 and 1996 and all patients with exstrophic bladder recorded in the files of the Hospital for Sick Children (Toronto, Ontario, Canada) and Dallas Children's Hospital (Dallas, Texas) between 1953 and 1987, and identified all patients with intestinal metaplasia of the bladder . Results. A total of 53 cases were identified from both series, and n one of the patients developed adenocarcinoma of the bladder. The Mayo Clinic series consisted of 24 patients. Nineteen of the 24 (79.1 %) we re alive without evidence of cancer (median follow-up 14 years, range 0.9 to 53), and 5 patients died of intercurrent disease (at 0.9, 4, 8, 11, and 53 years after diagnosis) without evidence of bladder cancer. The Dallas Children's Hospital and the Hospital for Sick Children ser ies consisted of 29 patients. Twenty-seven of the 29 (93.1%) were aliv e without evidence of cancer (median follow-up 13 years, range 3 to 23 .9). Two patients died of trauma (at 10.9 and 12 years after diagnosis ) and at autopsy had no evidence of bladder cancer. Conclusions. Intes tinal metaplasia of the urinary bladder is not a strong risk factor fo r adenocarcinoma or urothelial cancer. (C) 1997, Elsevier Science Inc. All rights reserved.