c-myc Amplification Is Frequent in Esophageal Adenocarcinoma and Correlated with the Upregulation of VEGF-A Expression

Abstract

BACKGROUND: Deregulation of c-myc plays a major role in the carcinogenesis of human malignancies. We investigated the amplification of the c-myc gene in a surgical series of Barrett cancers. METHODS: Primary resected esophageal (Barrett) adenocarcinomas (n = 84) were investigated for c-myc amplification using chromogene in situ hybridization. Tumor samples were assembled in a tissue microarray. c-myc gene dosage was correlated with clinicopathologic parameters, including the survival and gene expression of cyclooxygenases (COX-1 and COX-2) and proangiogenic growth factors (VEGF-A and VEGF-C). RESULTS: The majority (70 of 84; 83.3%) exhibited amplification of the c-myc gene. There were low-level amplifications in 63 (75.0%) cases and high-level amplifications in 7 (8.3%) cases. No amplification was found in 14 (16.7%) cases. Tumors without c-myc amplification had lower VEGF-A, VEGF-C, and COX-2 expression levels than tumors with low-level and high-level c-myc amplification (statistically significant for VEGF-A; P = .0348). c-myc amplification was not correlated with clinicopathological parameters or survival. Only diffuse and mixed-type tumors, according to Lauren classification, exhibited c-myc amplifications more frequently (P = .0466). CONCLUSIONS: Amplifications of the c-myc gene are frequent in Barrett cancer. c-myc may be involved in the regulation of angiogenesis.

Keywords

• c-myc
• esophageal adenocarcinoma
• Barrett cancer
• angiogenesis
• VEGF