Comparison between fluorescence in situ hybridization and classical cytogenetics in human tumors

Cytogenetic and fluorescence in situ hybridization (FISH) studies permit analyses of structural and numerical chromosome abnormalities. We compared modal chromosome count in cancer cells by FISH and classical cytogenetics (CC). Our cytogentic studies for chromosomes 3 and 17 on 134 human solid tumor cultures ¿57 small cell lung cancer (SCLC) and 77 non small cell lung cancers (NSCLC)¿, indicated a high incidence of numerical changes in these tumors. Using centromeric probes for chromosomes 3 and 17 we compared 15 tumor and 3 lymphoblastoid cultures, both by FISH (> 100 interphase nuclei) and by CC using trypsin-Giemsa G banding (> 20 metaphases). Although some intra-tumor heterogeneity was seen by FISH, we observed a high degree of concordancy (78%) in modal count by the two techniques.