Diagnostic accuracy of DNA image cytometry and urinary cytology with cells from voided urine in the detection of bladder cancer

Abstract

Objectives. To assess the potential of DNA image cytometry in screening for bladder cancer, compare it with conventional urinary cytology, and evaluate its possible use in routine urinary evaluation. Urinary cytology is still the most common method for detection of bladder cancer in routine clinical use. The considerable shortcomings of urinary cytology include its low sensitivity in low-grade carcinomas and its poor reproducibility. Methods. Spontaneously voided urine specimens from 40 patients with grade 1 (n = 27), grade 2 (n = 10), and grade 3 (n = 3) histologically proven transitional cell carcinoma and 40 patients with symptomatic urologic disease of the bladder were analyzed by cytology and DNA image cytometry. The DNA content was determined by use of the CM-1 Cytometer according to the guidelines in the ESACP Consensus Report on Standardization of DNA Image Cytometry. Results. Urinary cytology yielded an overall sensitivity of 47.5%. Conventional analysis of DNA histograms measuring the presence of DNA stemline aneuploidy (1.8c > stemline ploidy [STP] > 2.2c) revealed a sensitivity of 62.5%; applying the stemline interpretation according to Böcking et al. increased the overall sensitivity to 75%. The specificity of both methods was 100%. DNA image cytometry demonstrated a high sensitivity in grade 1 tumors (70.4%) compared with cytology (26%). Conclusions. In light of its highly improved sensitivity compared with urinary cytology, DNA image cytometry should be used to evaluate suspect urothelial cells in urinary cytology specimens. Since the method provides more objective and reproducible results with a specificity comparable to that of cytology, we encourage its primary application in the screening for bladder cancer, provided these results can be confirmed in a multicenter evaluation study.