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The use of flow cytometry for the diagnosis of bladder cancer requires a urine specimen that is obtained by bladder irrigation. Bladder wash flow cytometry is reported to be as sensitive or superior to voided urine or bladder wash cytology. To determine the suitability of voided urine for flow cytometric analysis, 59 patients with histories of bladder cancer were evaluated. Each patient provided three serially collected specimens for voided urine cytology and voided urine flow cytometry within a 24-hour period prior to cystoscopy, bladder irrigation for flow cytometry, biopsy and, if appropriate, tumor resection. Freshly voided urine specimens from 80 urologically normal individuals served as controls for the voided urine flow cytometry tests and specificity calculations. Thirty-two cases of bladder cancer were confirmed as positive for bladder cancer by biopsy. Evaluations of the three serial urine specimens revealed a greater sensitivity, increasing from the first to the third urine specimen, in both flow cytometry and voided urine cytology. The sensitivity was greater in the cytology tests than in the flow cytometry tests. Results from the control group indicated the necessity to analyze not less than 1,500 cells by flow cytometry for a reliable histogram. Voided urine specimens are not appropriate for flow cytometry analysis because insufficient urothelial cells are collected. In addition, voided specimens from female patients are frequently heavily contaminated with squamous epithelial cells from the periurethral area; these cells interfere with the analysis of the urothelial cells. (Consumer Summary produced by Reliance Medical Information, Inc.)

DNA flow cytometry has become increasingly accepted in recent years for monitoring the progress of bladder cancer patients, their therapeutic responses, and the status of transitional cell carcinoma (TCC). This study assessed the use of DNA flow cytometry as a screening procedure for bladder cancer. Two studies were conducted; the first was designed to identify the rate of false-positives (positive results in the absence of disease) among patients with benign prostatic hypertrophy (BPH) or urinary tract stones and no history of bladder cancer. Sixty-six patients with upper urinary tract stones and 24 males with BPH participated; all were at low risk for bladder cancer. DNA flow cytometry results revealed 4.4 percent unsatisfactory specimens and 15.1 percent abnormal histograms. The second study examined the effects of smoking on the rate of false-positive results with the DNA flow cytometry test. (Smoking is a risk factor for bladder cancer.) Urine samples were collected from 20 persons who never smoked, 10 who stopped smoking at least 20 years earlier, and 24 current smokers. With DNA flow cytometry, the false-positive rate for smokers was more than twice as high as the rate for nonsmokers, 14 percent and 36 percent, respectively. This excessive rate makes the DNA flow cytometry procedure inappropriate as a general screening test for bladder cancer. The background false-positive rate needs to be reduced if the DNA flow cytometry procedure is to be considered for screening. (Consumer Summary produced by Reliance Medical Information, Inc.)