Prognostic Significance of Preoperative Urine Cytology in Low-grade Non-muscle-invasive Bladder Cancer.
To examine the clinical significance of preoperative urine cytology in patients with low-grade bladder cancer. We retrospectively investigated the records of 155 patients diagnosed with primary low-grade (Ta) urothelial carcinoma of the bladder between January 2000 and September 2014. Patients with class III or greater cytology had significantly higher-grade (G2) (p=0.01), larger tumors (≥15 mm, p=0.0009) and significantly shorter recurrence-free survival compared to patients with class II or lower cytology (p<0.0001). However, Cox proportional hazards analysis for recurrence-free survival only identified tumor size (≥15 mm) (hazard ratio=5.97, 95% confidence interval=2.39-17.29; p<0.0001) as a predictor of poor prognosis, although patients with class III or higher preoperative cytology showed a tendency towards frequent intravesical recurrence (hazard ratio=1.98, 95% confidence interval=0.96-4.2; p=0.063). Preoperative urine cytology, in addition to tumor size, might be a useful predictor of intravesical recurrence of bladder cancer.