Aneuploidy of chromosome 8 and C-MYC amplification in individuals from northern Brazil with gastric adenocarcinoma.

BACKGROUND Gastric cancer is the third most frequent type of neoplasia. In northern Brazil, the State of Pará has a high incidence of this type of neoplasia. Limited data are available so far on the genetic events involved in this disease. MATERIALS AND METHODS Dual-color fluorescence in situ hybridization (FISH) for the C-MYC gene and chromosome 8 centromere was performed in 11 gastric adenocarcinomas. RESULTS All cases showed aneuploidy of chromosome 8 and C-MYC amplification, in both the diffuse and the intestinal histopathological types of Laurén. No correlation was found between polysomy 8 and the histopathological characteristics of the tumors. C-MYC amplification, like homogeneously-stained regions (HSRs) and double minutes (DMs), was observed only in the intestinal-type. Translocation of C-MYC was observed only in the diffuse-type. CONCLUSION Chromosome 8 can be used as a marker in the diagnosis of gastric adenocarcinoma. The C-MYC oncogene requires further studies in order to verify if it is, when amplified, an etiological cause of transformation or a consequence of the proliferation process.