Gastroenterology: Insulin-like growth factor 1 and insulin-like growth factor binding protein 3 linked to colorectal cancer risk

Background and objectives: Human studies have shown a correlation between the circulatory levels of insulin-like growth factor 1 (IGF1) and insulin-like growth factor binding protein 3 (IGFBP3) and the risk of colorectal cancerTherefore, this study performed complementary serological and Mendel random (MR) analyses to determine whether changes in IGF1 or IGFBP3 circulatory levels were associated with the onset of colorectal cancermethod: Between 2006 and 2010, researchers measured serum IGF1 levels from blood samples from 397,380 participants at Biobank UK and identified patients with cancerFull follow-up until March 31, 2016For MR analysis, the researchers identified genetic variations associated with cyclic IGF1 and IGFBP3 levelsresults: 2,665 cases of colorectal cancer were recorded 7.1 years after the study followedIn the multivariate adjustment model, the cyclic level of IGF1 is associated with the risk of colorectal cancer (the risk ratio of 1.11 per standard deviation increment for IGF1 is 1.11; 95% confidence interval (CI) 1.05-1.17)Similar associations were found through gender, follow-up time and tumor subsitesIn the MR analysis, an increase in the 1 standard deviation of IGF1 levels based on genetic factors was associated with a higher risk of colorectal cancer (OR1.08; 95% CI 1.03-1.12; P was 3.3 x 10-4)The level of IGFBP3 predicted based on genetic factors was associated with the risk of colorectal cancer (1.12 per 1 standard deviation increase; 95% CI 1.06-1.18; P - 4.2 x 10-5)The risk of colorectal cancer was associated with only one variant of the IGFBP3 gene region (rs111977526) and to anthrometric characteristics and the circulatory level of IGF2Conclusion: This study found a link between the circulatory levels of IGF1 and colorectal cancer