[Association of insulin, insulin-like growth factor and insulin-like growth factor binding proteins with the risk of colorectal cancer].

OBJECTIVE:To study the association of the changes of serum insulin, insulin-like growth factor (IGF-1), insulin-like growth factor binding proteins(IGFBPs), body mass index (BMI), waist and hip circumference ratio(WHR) with the genesis of colorectal cancer. METHODS:Sera from 244 colorectal cancer patients before operation, 371 patients after operation and 150 healthy subjects were assayed for insulin, leptin, IGF-1, IGFBP-1 and IGFBP-3 by the enzyme-linked immunosorbent assay. SPSS 13.0 statistics software was applied to analyze the data. RESULTS:The serum levels of insulin, IGF-1 and the ratio of IGF-1/ IGFBP-3 in colorectal cancer patients before and after surgical treatment were significantly higher than those in controls. The serum levels of IGFBP-3 in patients before and after operation were significantly lower than those in controls, and the differences were significant(P=0.015,P=0.001, respectively). The BMI in colorectal carcinoma patients was not significantly different to the healthy controls(P>0.05). The WHR in colorectal carcinoma patients was higher than that in healthy subjects, and the difference was significant(P=0.003, P=0.035 respectively). The WHR in colon cancer patients was different to that in rectal cancer patients(P=0.046). The WHR and BMI in colon carcinoma patients were positively correlated with the serum insulin level and the value of IGF/IGFBP3. The WHR and BMI were negatively correlated with IGFBP3. The WHR and BMI were not correlated with IGF-1 and IGFBP1. CONCLUSIONS:The serum insulin, IGF-1 levels and the value of IGF-1/IGFBP-3 are significantly increased in colorectal cancer patients, and serum IGFBP-3 level is markedly decreased, which may be related to the genesis of colorectal cancer, but are not correlated with the progress and improvement of colorectal cancer. Central adipositas may be a risk factor for the genesis of colon cancer.