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Test designed to help in bladder cancer diagnosis (8/10/95)A new, easy-to-use diagnostic test should prove valuable to urologists watching for recurrence of bladder cancer in patients, according to results of a multicenter trial. The Bard bladder tumor antigen test (BTA) is more sensitive than conventional urinary cytology studies in detecting recurrent bladder cancer, say researchers at The University of Texas Health Science Center at San Antonio and 11 other institutions nationwide. Their results are reported in this month's issue of *The Journal of Urology*. "This test is simple, rapid and inexpensive; it can be performed in the office and results are available almost immediately," said Michael F. Sarosdy, MD, professor of surgery at the Health Science Center and clinical coordinator of the nationwide BTA trial. He is lead author of the paper. More than 50,000 people are diagnosed with bladder cancer annually in the United States. Seventy-five percent have superficial or early cancer that can be treated without removal of the bladder, but the disease will recur in at least half of these patients. Cytology is a pathological test on voided urine and may detect cancer cells if they are shed from the tumor. This test takes one to two days or longer, and requires both a technician and a pathologist to interpret. The BTA test results, also from urine, are available much sooner. In one portion of the study, the two tests were performed in 151 patients who were found to have bladder cancer. The bladder tumor antigen test detected 40 percent of these cancers, compared to only 17 percent for the urinary cytology test. "An apparent advantage for the bladder tumor antigen test compared to voided urinary cytology is the much higher sensitivity of the former test for lower-grade tumors," the authors report. "Among the 61 patients with low-stage and low-grade tumors, the bladder tumor antigen test sensitivity was 30 percent compared to voided urinary cytology sensitivity of only 3 percent." The BTA test is easy to perform and interpret, the authors say. Following a chemical reaction, a visual color change distinguishes positive from negative results by use of a test strip. "In most cases, the disease is positively diagnosed by means of an invasive procedure called a cystoscopy," Dr. Sarosdy said. "Based on our study of 499 patients nationwide, we believe the BTA test may be used by urologists as a suitable adjunct to cystoscopy. In this trial, the BTA results were equivalent or superior to those of urinary cytology studies." The researchers still recommend that cystoscopy be performed, but add that "future studies will determine if, in fact, the bladder tumor antigen test will permit a reduction in the number of cystocopic studies by 50 percent or greater with no detriment to the patient." Contact: Will Sansom (210) 567-2570
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