Microsatellite analysis - DNA test in urine competes with cystoscopy in follow-up of superficial ladder carcinoma - A phase II trial

BACKGROUND. It has been shown that microsatellite analysis (MA) is able to detect bladder carcinoma in urine. Relatively small groups of patients ofte n with high stage and grade disease were investigated. However, greater tha n 85% of cystoscopies are performed for follow-up of superficial bladder ca rcinoma. The authors evaluated this DNA-based method in a group of consecut ive patients in follow-up after transurethral resection of superficial dise ase. METHODS. Matched blood and urine samples from 109 patients were obtained be fore cystoscopy and subjected to MA. The BTA scat test (Bard Diagnostic Sci ences, Inc., Redmond, WA) and cytology were used for comparison. RESULTS. Sixteen patients were excluded: the DNA was of insufficient qualit y for 7 patients and leukocyte abundance rendered the result of MA unreliab le for 9 patients. For the remaining 93 patients, MA detected 18 of the 24 recurrent tumors. The six undetected tumors were small pTaG1 lesions for wh ich immediate surgery was not necessary. Conversely, 5 of 9 patients with a positive MA and a negative cystoscopy had a tumor recurrence within 6 mont hs after urine collection. In contrast, a recurrence occurred in only 7 of 60 patients who were negative in both MA and cystoscopy (P = 0.006). The MA (74%) appeared more sensitive than the BTA stat test (56%) or urine cytolo gy (22%). CONCLUSIONS. Microsatellite analysis is a DNA test in urine that reliably s ignals the presence of recurrent bladder carcinoma, sometimes even before c ystoscopic evidence of the disease. This noninvasive diagnostic tool has th e potential to replace cystoscopy in many cases. The authors' results warra nt the need for randomized trials. (C) 2001 American Cancer Society.