The relationship of genetic aberrations detected by comparative genomic hybridization to DNA ploidy and tumor size in human oral squamous cell carcinomas

We have examined genetic alterations in 11 surgically removed oral squamous cell carcinomas (OSCCs) using comparative genomic hybridization (CGH) and laser scanning cytometry (LSC), which allow quantitative analysis of chromo somal abnormalities. CGH analysis revealed gains and/or losses of DNA seque nce copy number in all tumors. Gains in DNA sequence copy number were detec ted frequently for chromosome arms 3q25-28 (6/11), 5p (6/11) and 8q (5/11), and losses in chromosome arms 18q (4/11), 19q (4/11), 17p (3/11), and 19p (3/11). Amplification of 5p was observed in two tumors. LSC detected DNA an euploidy with DNA indices ranging from 1.30 to 1.82 in 6 of 11 tumors. The number of chromosomal aberrations was higher in DNA aneuploid tumors than i n diploid tumors (8.17 vs 3.60/tumor, P<0.05). Furthermore, the average num ber of chromosomal aberrations was significantly higher in stage T2 tumors and larger tumors than in stage T1 tumors (7.71vs 3.25/tumor, P<0.05). Our results suggest that DNA aneuploidy and large tumor size reflect an underly ing chromosomal instability.