“…With the use of banding techniques, aberrations can be assigned to specific chromosomes and significant non-random abnormalities have been identified on chromosomes 1, 3, 5 , 7, 9, 11 and 17.52 Cairns et al examined 162 bladder cancers for evidence of structural alterations to the RB gene; 94 were informative, and 28 (29%) of these showed loss of heterozygosity (LOH) . 52 Of the 28 tumors with LOH, 26 were muscleinvasive, while only two out of 48 (14%) superficial tumors showed RB allele loss, one progressing rapidly to invasive disease. These results show that LOH at the RB locus is a frequent genetic event in bladder cancers and may identify a subset of more aggressive tumors.…”