Future Medicine, Pharmacogenomics, 9(11), p. 1247-1256, 2010
DOI: 10.2217/pgs.10.92
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Aim: IGF binding protein-3 (IGFBP-3) displays growth inhibitory/proapoptotic action and counteracts the IGF-1 tumor-promoting effects by downregulating its bioavailability. We investigated whether IGFBP-3 SNPs determining high IGFBP-3 circulating levels are associated with improved survival of patients with advanced gastric cancer treated with palliative chemotherapy. Materials & methods: A total of 185 patients undergoing combination chemotherapy for relapsed/metastatic disease were considered eligible for the present clinical investigation. Four functional IGFBP-3 SNPs (rs3110697, rs2854746, rs2864744 and rs2960436) were studied for association with overall survival (OS). Results: In the multivariate model including SNPs and clinicopathologic features, the rs285744 A allele and the rs2960436 A allele showed favorable association with survival. The hazard ratios for rs285744 C/A and A/A genotypes were 0.38 (95% CI: 0.18–0.66) and 0.20 (95% CI: 0.09–0.39), respectively. The hazard ratios for rs2960436 G/A and A/A genotypes were 0.41 (95% CI: 0.25–0.68) and 0.35 (95% CI: 0.16–0.58), respectively. Bonferroni-corrected p-values for the rs285744 A/A genotype and the rs2960436 A/A genotype were 0.012 and 0.024, respectively. There was linkage disequilibrium between the four variants and there were four common haplotypes (>5% estimated frequency). The most common haplotype (GCAA) included all alleles causing IGFBP-3 upregulation and their carriers demonstrated the best outcome in the log-rank comparison of survival curves. Conclusion: Genetic regulation of the IGFBP-3 impacts on survival of patients with advanced gastric cancer. This finding deserves additional studies because of its prognostic and therapeutic implications.