DNA aberrations in urinary bladder cancer detected by flow cytometry and FISH

Detection of molecular alterations is of potential significance for diagnosis and prognosis in bladder cancer. Fluorescence in situ hybridization (FISH) allows visualization and quantitation of genes and chromosomes on a cell by cell level and can easily be applied to urinary cells. To evaluate the sensitivity of FISH for detection of DNA aberrations in bladder cancer, formalin-fixed tissues of 293 tumors were examined by FISH and flow cytometry (FCM). Centromere probes for the chromosomes X, Y, 1, 7, 9, and 17 were used for FISH analysis. FISH was more sensitive for detection of quantitative DNA aberrations than FCM. An aberration of at least one chromosome was found in 107 of 108 tumors (99%), which were tetraploid, aneuploid, or multiploid, and in 29 of 49 tumors (59%), which were diploid, by FCM. The frequency of FISH aberrations showed greater differences between pTa (47%) and pT1 tumors (85%;P