Genetic detection of bladder cancer by microsatellite analysis of p16, RB1and p53 tumor suppressor genes

Purpose: We investigated the incidence of genetic alterations in urine spec imens from patients with bladder cancer. Materials and Methods: A total of 28 cytological urine specimens were asses sed for microsatellite alternations, and 15 microsatellite markers were loc ated on p53, RB1 and p16 regions. In 15 patients DNA from tumor specimens w as also available. Results: Loss of heterozygosity was detected in 26 of 28 patients (93%) in at least 1 microsatellite marker. Allelic losses were found in 18 patients (64%) for the p16 locus, in 8 (29%) for the RE 1 locus and in 17 (61%) for the p53 region. In contrast, no microsatellite alterations were found in th e normal group without evidence of bladder cancer. In 11 cases genetic alte rations in the cytological urine specimens were not detectable in the corre sponding tumor specimen, suggesting heterogeneity of bladder cancer. Conclusions: The detection of loss of heterozygosity in cytological urine s pecimens may be a prognostic indicator of early detection of bladder cancer . Our results suggest that microsatellite analysis of urine specimens repre sents a novel, potentially useful, noninvasive clinical tool to detect blad der cancer.