OBJECTIVETo 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.

METHODSSera 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.

RESULTSThe 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.

CONCLUSIONSThe 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.