Relationship between insulin-like growth factor axis gene polymorphisms and clinical outcome in advanced gastric cancer patients treated with FOLFOX.

The insulin-like growth factor (IGF) axis plays a crucial role in proliferation, differentiation, migration, angiogenesis, and apoptosis. The present study evaluated the associations between IGF axis single-nucleotide polymorphisms (SNPs) and clinical outcomes in advanced gastric cancer (AGC) patients treated with oxaliplatin, 5-fluorouracil, and leucovorin (FOLFOX). A total of 190 patients undergoing FOLFOX chemotherapy for AGC were considered eligible for this study. Forty-four SNPs of 10 IGF axis genes were genotyped. Levels of serum IGF1 were measured using enzyme-linked immunoassays. SNPs of the IGF1R (rs12423791), and IGF1 (rs2162679, rs5742612, rs35767) genes were significantly associated with tumor response to FOLFOX. SNPs of rs4619 and rs17847203 were significantly associated with PFS (hazard ratio [HR] 0.575, 95% CI 0.385-0.858, P = 0.007; and HR 2.530, 95% CI 1.289-4.966, P = 0.007; respectively). SNPs of rs2872060 were significantly associated with OS-OS was shorter in patients carrying the TT variant than in those with the GG/GT genotypes (HR, 1.708, 95% CI 1.024-2.850, P = 0.040). The GT genotype of rs12847203 was also identified as an independent prognostic factor (HR 2.087, 95% CI 1.070-4.069, P = 0.031). These results suggest that IGF axis-pathway SNPs could be used as prognostic biomarkers of the outcome of FOLFOX chemotherapy in AGC patients. This information may facilitate identification of population subgroups that could benefit from IGF1R-targeted agents.