MICROSATELLITE INSTABILITY IN TRANSITIONAL-CELL CARCINOMA OF THE URINARY-TRACT AND ITS RELATIONSHIP TO CLINICOPATHOLOGICAL VARIABLES AND SMOKING

To determine whether microsatellite instability is involved in the dev elopment of transitional cell carcinoma (TCC) of the urinary tract, a microsatellite instability assay was carried out using PCR with 9 micr osatellite loci. Thirty-eight TCC samples (30 patients with bladder ca ncer, 5 with renal pelvic tumors and 3 with ureteral tumors) and 1 lym ph node with metastasis were examined. Microsatellite instability was found in 8 of 38 tumors examined, and 3 showed alterations in more tha n 2 microsatellite loci. All 8 tumors were beyond grade 2 and stage pT 2 advanced tumors. Stages pT1-2 and pT3-4 patients differed significan tly. Microsatellite instability was greater in smokers than non-smoker s, but the differences were not significant. Microsatellite instabilit y in TCC of the urinary tract is rare in superficial tumors but more c ommon in invasive tumors. Microsatellite alterations would thus appear to occur, and possibly be importantly involved, in the tumorigenesis of urinary tract TCC. (C) 1996 Wiley-Liss, Inc.