Comparison of comparative genomic hybridization, fluorescence in situ hybridization and flow cytometry in urinary...

Comparative genomic hybridization (CGH) was applied to screen the genetic events in six invasive urinary bladder cancers. These cases were also studied by flow cytometry (FCM) and fluorescence in situ hybridization (FISH). Four samples showed partial gain on chromosome 8, with the common region involved was on 8q23-qter. Full or partial deletion on chromosome 2 and 17p in addition to gain on 20q was found in two cases. Interestingly one diploid tumor with low mitotic index, stage and grade showed more genetic aberrations (8 gains and 7 losses) by CGH than other aneuploid tumors with high mitotic index, stage and grade. The numerical chromosomal aberration detected by FISH for chromosomes 7, 8, 9, 10, 11 and 17 were 50% in T1 cases and 100% in T2-T4 cases. FISH was performed on chromosome 8q and 17p to compare and validate the sensitivity of CGH. The agreement was 100% for 8q24 locus and 50% for p53 locus. This indicates that different molecular genetic techniques showed relatively different aspect of genomic aberrations.