Abstract 2795: Serum IGF-I, IGF-II, IGFBP-3, and IGF-I/IGFBP-3 molar ratio and risk of pancreatic cancer in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial

Abstract

Abstract Experimental evidence suggests that an overexpression of insulin-like growth factor-I (IGF-I) is implicated in human pancreatic tumors. Moreover, increased IGF-II and decreased insulin-like growth factor binding protein-3 (IGFBP-3) concentrations are found in a number of cancers. We conducted a nested case-control study in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial cohort of men and women 55-74 years of age at baseline, to test whether pre-diagnostic circulating IGF-I, IGF-II, IGFBP-3, and IGF-I/IGFBP-3 molar ratio concentrations were associated with exocrine pancreatic cancer risk. Between 1994 and 2006, 187 incident cases of pancreatic adenocarcinoma occurred (follow-up to 11.7 years). Two controls (n=374),who were alive at the time the case was diagnosed, were selected for each case and matched by age, race, sex and date of blood draw. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) using conditional logistic regression, adjusting for smoking. In the multivariable adjusted model, IGF-I, IGF-II, and IGFBP-3 concentrations were not associated with pancreatic cancer (highest compared with lowest quintile, OR=1.23, 95% CI 0.67-2.25, p-trend=0.12; OR=0.98, 95% CI 0.52-1.85, p-trend=0.52; and OR=1.15, 95% CI 0.62-2.16, p-trend=0.90). However, a significant positive trend was observed with high IGF-I/IGFBP-3 molar ratio levels in the smoking-adjusted model (OR=1.46, 95% CI 0.78-2.74, p-trend=0.04). A higher IGF-I/IGFBP-3 molar ratio may represent increased free IGF-I and be a risk factor for pancreatic cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2795.