Microsatellite analysis--DNA test in urine competes with cystoscopy in follow-up of superficial bladder 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 often with high stage and grade disease were investigated. However, greater than 85% of cystoscopies are performed for follow-up of superficial bladder carcinoma. The authors evaluated this DNA-based method in a group of consecutive patients in follow-up after transurethral resection of superficial disease.


METHODS
Matched blood and urine samples from 109 patients were obtained before cystoscopy and subjected to MA. The BTA stat test (Bard Diagnostic Sciences, Inc., Redmond, WA) and cytology were used for comparison.


RESULTS
Sixteen patients were excluded: the DNA was of insufficient quality for 7 patients and leukocyte abundance rendered the result of MA unreliable 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 which immediate surgery was not necessary. Conversely, 5 of 9 patients with a positive MA and a negative cystoscopy had a tumor recurrence within 6 months 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 cytology (22%).


CONCLUSIONS
Microsatellite analysis is a DNA test in urine that reliably signals the presence of recurrent bladder carcinoma, sometimes even before cystoscopic evidence of the disease. This noninvasive diagnostic tool has the potential to replace cystoscopy in many cases. The authors' results warrant the need for randomized trials.
van Rhijn
B W
BW
Department of Pathology, Josephine Nefkens Institute, Erasmus University Rotterdam, 3000 DR Rotterdam, The Netherlands.
Lurkin
I
I
Kirkels
W J
WJ
van der Kwast
T H
TH
Zwarthoff
E C
EC
D000368:Aged; D003558:Cystoscopy; D004273:DNA, Neoplasm / Q000652:urine*; D005260:Female; D006801:Humans; D019656:Loss of Heterozygosity; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000473:pathology / Q000652:urine*; D012680:Sensitivity and Specificity; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000652:urine*
D004273:DNA, Neoplasm