Urinary cytology in the detection of bladder tumours. Influence of concomitant urothelial atypia.

ABSTRACT

The role of urinary cytology in detection and follow-up of urinary bladder tumours is still evolving. However, considerable variations in the accuracy of detecting bladder tumours exist in published work on the subject. In this study the influence of concomitant urothelial atypia on urinary cytology was investigated. Further, the correlation of grading between cytology and tumour histology was examined, and finally the role of urinary cytology as a prognostic factor was investigated. 102 comparative studies of simultaneously achieved precystoscopic voided urine samples, tumour histology and 8 pre-selected site biopsies were available from patients having a Ta, T1 or T2 bladder tumour. The overall numbers of positive cytology were found to be 64%, but correcting for false positives caused by concomitant urothelial atypia the numbers were reduced to 55% (p less than 0.01). A considerable higher ability to detect high-grade than low-grade tumours was found. Correlation between grading of tumour histology and cytology was found to be only 50%. Patients were followed for 3 years. From the results of pre-cystoscopic cytology it was possible to define a low-risk group and a high-risk group. Patients with negative cytology had very low risk of future invasive tumour recurrence whereas all patients with grade III-IV cytologic changes were found to harbour either a grade III tumour or carcinoma in situ, both conditions predictive of aggressive tumour course.