Analysis of polymorphisms in EGF, EGFR and HER2 genes in pancreatic neuroendocrine tumors (PNETs).

OBJECTIVES: Pancreatic neuroendocrine tumors (NETs) are rare and account for about 7% of all cancers occurring in the pancreas. The epidermal growth factor family of receptors and their ligands play an important role in the growth and progression of tumors but their role in PNET development remains unknown. We hypothesized that functional single nucleotide polymorphisms (SNPs) in the EGF, EGFR, and HER2 genes might affect individual susceptibility to PNETs development and invasion like it was shown for various other tumors. METHODS: We genotyped 68 patients with unresectable PNETs and 300 controls to evaluate the association between EGF, EGFR, and HER2 polymorphisms and susceptibility to PNETs and presence of metastases. RESULTS: Genotype analysis of three SNPs EGF +61A/G (rs4444903), EGFR +1562 G/A (rs11543848), and HER2 +1963 A/G (rs1136201) showed that carriers of EGFR +1562 AG genotype and AA/AG EGF +61/HER2 +1963 genotype combination are at risk of developing PNET. Furthermore, EGFR +1562 AA genotype could be associated with the susceptibility to insulinoma development. CONCLUSIONS: Our results suggest involvement of EGFR signaling pathway in etiology of PNET development.