Effect of Urinary Cytology for Detecting Recurrence in Remnant Urothelium After Radical Cystectomy: Insights From a 10-year Cytology Database

Recurrence in the remnant urothelium is observed in ≤ 8% of cases, depending on the type of urinary diversion, with higher rates of urethral recurrence in heterotopic diversions. Thus, the diagnosis of recurrence in the remnant urothelium is challenging. In our series, urinary cytology had a sensitivity and specificity of 75.0% and 98.8% for detecting urethral recurrence, respectively. Approximately 70% of urethral recurrence cases were detected by cytology alone before the patients developed clinical symptoms, thus influencing consecutive survival. We evaluated the diagnostic accuracy of urinary cytology (UCy) for detecting recurrence in the remnant urothelium (RRU) after radical cystectomy (RC) for urothelial cancer. We conducted a 10-year retrospective analysis of a prospectively collected, single-center RC database comprising 177 patients who had undergone follow-up examinations at our department with ≥ 1 available postoperative UCy specimen. UCy specimens were classified using the Papanicolaou scheme. In total, 957 cytology specimens were collected. Negative UCy results were noted in 927 (96.8%), atypical urothelial cells in 19 (2.0%), and suspicious/positive for malignancy in 11 (1.2%) cases. RRU was diagnosed in 16 patients (9.1%) during a mean follow-up period of 37 months (range, 1-118 months). The mean interval from RC to RRU was 34.7 months. Only 2 of 11 positive UCy specimens (18.2%) were falsely positive, for an overall sensitivity and specificity of 56.3% and 98.8% for predicting RRU, respectively. Urethral recurrence was diagnosed by UCy alone before the patients had developed symptoms in 8 of 12 cases (66.7%). Patients with clinical symptoms at the diagnosis of RRU had poorer cancer-specific survival rates than those of asymptomatic patients, although this trend was not statistically significant (P = .496). Moreover, positive UCy findings were associated with significantly lower overall survival (P < .001) and cancer-specific survival (P = .04) compared with negative UCy findings. Our results underline the predictive value of UCy in the surveillance of the remnant urothelium, with early detection of urethral recurrence before the development of clinical symptoms.