Urinary cytology for the detection of urothelial carcinoma of the bladder—a flawed adjunct to cystoscopy?

Abstract

ObjectivesTo test the sensitivity of urinary cytology at a tertiary academic institution and to assess the impact of pathologist' experience on detection of urothelial carcinoma of the bladder (UCB). Materials and methodsBetween April 1999 and September 2008, 8,574 cytology specimens were evaluated. There were 882 consecutive patients (612 males, 270 females) who underwent bladder biopsy or transurethral resection of bladder tumor for UCB. Sensitivity rates of prior urinary cytology were determined. We tested the influence of experience of pathologist on sensitivity. ResultsUrinary cytology detected 237 out of 503 UCB (overall sensitivity 47.1%). Cytology after bladder washing resulted in higher sensitivity than in voided urine (50.4% vs. 36.2%; P = 0.008). Sensitivity rates significantly increased by UCB stage; 30.6% in pTa (n = 245), 60.5% in patients with any form of CIS (n = 119), 62.9% in pT1 (n = 89), and 69.6% in ≥pT2 (n = 46; P < 0.001). Similarly, higher sensitivity was observed with increasing grade, ranging from 16.7% in low (n = 108) to 62.2% in high grade tumors (n = 283; P < 0.001). No statistically significant difference between more and less experienced investigators was observed. ConclusionsSensitivity rates of urinary cytology at our institution are not superior to those reported in the literature. Cytology missed many high grade cancers, pointing to inherent methodological limitations of urinary cytology. A higher experience level of the pathologist was not significantly associated with higher sensitivity rates. Urinary cytology represents a flawed adjunct to cystoscopy with limited potential of improvement even in the hands of experienced pathologists.