C-MYC Locus Amplification as Metastasis Predictor in Intestinal-type Gastric Adenocarcinomas: CGH Study in Brazil

Background: The genetic events involved in gastric cancer, the third most frequent cancer in the world with a high incidence in Pará State, Brazil, remain largely unknown. Materials and Methods: Twenty-one primary gastric adenocarcinomas were investigated by comparative genomic hybridization (CGH) and the relationships between genomic abnormalities and histopathological features were evaluated. Results: Eighty-one percent of cases presented DNA copy-number changes. Chromosomal gains were the most frequent finding, losses occurring only in the diffuse type. The main copy-number gains were on chromosome 8, principally on 8q24.1 (8/21 cases), 8p21 (3/21) and 8p23.2-8p12 (2/21). Gain of region 8q24.1, where C-MYC is located, was the main finding, exclusively in the intestinal type with metastasis. Conclusion: C-MYC locus amplification may be predictor of aggressiveness in intestinal-type gastric cancer, playing an important role in its development and progression. Moreover, other genes on 8q24 should be investigated. Gastric adenocarcinomas of differing histopathological features were associated with distinct genetic alterations, supporting the hypothesis that they evolve through distinct genetic pathways.