The prognostic value of polymorphisms in the insulin-like growth factor receptor (IGFR) pathway in patients with locally advanced pancreatic cancer (LAPC)

Abstract

4500 Background: The IGFR pathway is activated in pancreatic cancer and may result in aggressive disease course. The study of single nucleotide polymorphisms (SNPs) involved in this pathway may provide prognostic information and predict response to IGFR directed agents. We investigated IGFR pathway SNPs in patients with LAPC. Methods: We evaluated 39 SNPs from 7 candidate genes in the IGFR pathway (IGF1R, IGF2R, IGF1, IGF2, IRS1, IRS2, IGFBP3) in 105 LAPC patients. DNA extraction from whole blood was performed using the Qiagen Flexigene DNA and Promega Maxwell 16 kits. Genotyping was performed using the Sequenom method. Overall survival was measured from date of diagnosis to date of death or last follow-up. Kaplan-Meier plot, log-rank test, and Cox regression were used to compare survival of patients according to genotype corrected for previously identified prognostic factors, including induction chemotherapy, CA 19–9, albumin, LDH, hemoglobin and Karnofsky performance status (KPS). Results: Median survival time (MST) was 15 months (95% CI 13.3–16.7). Induction chemotherapy, LDH, CA 19–9 level, hemoglobin, and KPS were not significantly associated with survival. Serum albumin and three SNPs of the IGF pathway (IGF1R IVS20–3431A>G, IRS1 G971R, and IGF2 *4352A>G) were significantly associated with prognosis ( Table ). Two of the three genotypes remained as significant predictors for survival in Cox regression analysis when adjusted for clinical factors. A significant combined genotype effect was observed wherein patients with all three deleterious alleles had significantly worse survival than those with only two or one (10 vs. 16.3 vs. 21.3 months, p< 0.0001). Conclusions: These data suggest that SNPs in the IGFR pathway genes may have prognostic value for LAPC patients. This information may identify population subgroups that could benefit from IGFR-targeted agents. [Table: see text] No significant financial relationships to disclose.