Document Type

Article

Disciplines

Medicine and Health Sciences

Abstract

Background Dysregulation of the insulin-like growth factor (IGF) system, a common consequence of adiposity-induced insulin resistance, may be a key underlying mechanism linking excess body weight with colon cancer. Evidence has been derived from studies of cancer and polyps. Supporting data about aberrant crypt foci (ACF), putative pre-polyp changes, have been generated only from animal studies to date. Methods We randomly selected 26 patients with sex-specific elevated waist-hip-ratio (WHR) and 26 with normal values from a series of 150 patients seeking routine colonoscopy at the University of Connecticut Health Center. Cross-sectional analyses were performed of ACF number (<5, ≥5) in relation to total IGF1, IGF-binding protein-3 (IGFBP3), insulin, body mass index (BMI), WHR and waist circumference (WC). Visualized ACF in the 20 cm of the distal colon were counted using advanced endoscopic imaging. Results Patients with ≥5 ACF had higher BMI, WHR, and WC compared with patients with >5 ACF (p = 0.04, p = 0.03, and p = 0.01, respectively). IGFBP3 was reduced (p = 0.02) and IGF1:IGFBP3 molar ratio was greater (p = 0.03) in patients with ≥5 ACF. We did not observe significant associations between ACF number and insulin or total IGF1. Conclusions Our study provides the first report in humans of a possible association of ACF prevalence and IGF1 bioavailability as characterized by IGF1:IGFBP3 molar ratio and IGFBP3 level. More research is needed to determine whether this relationship is varied by ACF features (e.g., size, dysplasia, molecular changes), synchronous cancer and polyps, and is modified by colon cancer risk factors.

Comments

Cancer Causes Control. Author manuscript; available in PMC 2011 May 23. Published in final edited form as: Cancer Causes Control. 2009 July; 20(5): 653–661.
Published online 2008 December 9. doi: 10.1007/s10552-008-9278-7.

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