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.