Numerical aberrations of chromosome 8 detected by conventional cytogenetics and fluorescence in situ hybridization in individuals from northern Brazil with gastric adenocarcinoma.

Gastric cancer is the third most frequent type of neoplasia and the second most important cause of cancer-related death in the world. In northern Brazil, the state of Pará shows a high incidence of this disease and the capital ranks among cities with the highest incidence of stomach cancer in the world. To evaluate chromosomal aberrations implicated in gastric carcinogenesis, we analyzed 16 samples of gastric adenocarcinoma by fluorescence in situ hybridization using a chromosome 8 alpha-satellite probe and by direct chromosomal analysis techniques. All lesions were classified as at advanced stages according to the recommendations of the Union Internationale Contre le Cancer (UICC). Trisomy 8 was the main finding of this study, observed in all cases. There was no significant difference between chromosome 8 ploidy and localization, stage, or histological type of adenocarcinoma in our sample. The high incidence of alterations we found in chromosome 8 may be a regional characteristic, related to the high incidence of this neoplasm in Pará state and a strong influence of external factors, such as eating habits. This aberration may comprise a cytogenetic subgroup of this neoplasm. Additional investigations are necessary to confirm the involvement of chromosome 8 and to identify genes in this chromosome related to gastric carcinogenesis.