The clinical significance of urine cytology after a radical cystectomy for urothelial cancer

Objectives: To evaluate the impact of urine cytology on the prediction of the upper urinary tract recurrence (UTR) of urothelial cancer after a radical cystectomy (RC) with urinary diversion. Methods: A total of 125 patients who underwent RC from 1987 to 2005 were retrospectively identified. The median follow-up period was 64 months. The specimens for urine cytology were obtained from the urine voided or obtained through a catheter or a conduit. The relationship between a positive urine cytology result and UTR detection was determined. Results: UTR was diagnosed in eight patients (6.4%) at a median follow-up of 63.3 months. The overall rate of a positive urine cytology result was 12.3% for the urine in an ileal conduit, 18.8% in a continental reservoir and 10.5% in an orthotopic neobladder. The overall sensitivity and specificity of the urine cytology for the detection of UTR were 75.0% and 90.6%, respectively. However, UTR could be diagnosed earlier by using urinary cytology, rather than by radiological examinations and/or related symptoms in only 5.9% (1/17 positive urine cytology) of cases. Eleven (64.7%) of 17 patients with positive urine cytology were false positive and eight (72.7%) of the 11 patients with no UTR had a positive urine cytology result only once. Conclusions: Urine cytology after RC was not a potent screening tool for the early detection of UTR because of the difficulty in distinguishing the cancer cells from degenerated intestinal epithelial cells in the urinary diversion urine.