Objective: Colorectal cancer (CRC) is one of the most common malignancies worldwide. Colorectal carcinogenesis has associated with the progressive acquisition of a variety of genomic alterations by neoplastic cells, some of these have been linked to early stages of CRC development. The aims of this study (1) to identify alterations of chromosome 8 in primary colorectal carcinomas from Turkish patients and (2) to determine which alterations of chromosome 8 are early events during the development of colorectal carcinoma using fluorescence in situ hybridization (FISH).

Materials and Methods: To reveal the significance of genetic abnormalities of the chromosome 8, 28 colorectal tumors were analyzed using FISH. The centromeric-probe for chromosome 8 was used for FISH. In each case, at least 200 nuclei were scored for each hybridization.

Results: Monosomy in 3.6%, disomy in 39.3%, trisomy in 53.6% and tetrasomy in 3.6% of the analyzed adenomas were determined. Chromosome 8 gain was found in 5 of 8 (62.5%) nonpolypoid and 3of 9 (33.3%) polypoid cancers. There was statistically significant correlation between chromosome 8 gain and stage of CRC.

Conclusions: There are several reports of chromosome 8 gain in solid tumors. FISH is a useful method to detect genetic abnormalities in solid tumors. It was shown that chromosome 8 gain FISH associated with the stage of CRC. Chromosome 8 monosomy may be a early event in CRC. Further studies involving more patients need to determine the importance of this alteration in CRC. ©2007, Firat University, Medical Faculty