Increased polysomy 3 and 17 detected by fluorescence in situ hybridization (FISH) in oral squamous cell carcinoma

Numerical chromosome aberrations were studied by fluorescence in situ hybridization (FISH) using pericentromeric DNA probes specific for chromosomes 3 and 17 in 18 oral squamous cell carcinomas (SCCs) and 3 lymph nodes as control. Disomy 3 and 17 was detected in approximately 90% of control cells, and in 60.9 +/- 4.0% and 62.7 +/- 3.6% of SCCs, respectively. Polysomy 3 and 17 significantly increased in SCCs when compared to controls. The pattern of chromosome aberrations varied considerably between cases. There was no obvious relationship between the degree of polysomies and clinicopathological factors such as tumor-differentiation, stage of the disease and clinical outcome. Chromosome aberrations by FISH did not correlate with DNA aneuploidy by flow cytometry. Our results indicate that oral SCCs are more frequently associated with the increased copy number of chromosomes 3 and 17 than previously thought, and that a correlation between chromosome aberrations by FISH and DNA aneuploidy by flow cytometry is not obvious.