Expression of insulin-like growth factor 1 and its receptors in colorectal cancer and their significances / 肿瘤研究与临床

ABSTRACT

Objective To investigate the expression of insulin-like growth factor 1 (IGF-1), insulin growth factor receptor 1(IGF-1R)and insulin growth factor receptor 2(IGF-2R)in colorectal cancer, and their relationship with the relevant clinicopathological factors. Methods Immunohistochemical SP method was used to detect the expression of IGF-1,IGF-1R and IGF-2R in 154 cases of colorectal cancer tissues,58 cases of benign disease tissues (colorectal adenoma, polyps) and 90 normal tissues. Results The positive rate of IGF-1 and IGF-1R expression in colorectal cancer tissues [93.5%(144/154), 70.1%(108/154)] was higher than that in benign diseases [51.7%(30/58), 51.7%(30/58)] and adjacent normal tissues [18.9%(17/90), 35.6%(32/90)] (P=0.001). The positive expression rate of IGF-1 and IGF-1R in colorectal cancer tissue, benign disease tissue and adjacent normal tissues decreased gradually, and there was significant difference between any two groups (P<0.05). The positive expression rate of IGF-2R had no significant difference between any two groups (P>0.05). IGF-2R was significantly different between any two groups (P<0.05). The expression of IGF-1R and IGF-2R in colorectal cancer tissues were not significantly correlated with gender, location, tumor size, family history, depth of tumor invasion and local lymph node metastasis (all P>0.05).IGF-1 was positively correlated with the body mass index(r=0.169,P=0.036).IGF-2R was negatively correlated with age (r=-0.196, P=0.015), and positively correlated with TNM staging in patients with colorectal cancer (r=0.227, P=0.005). The expression of IGF-1 was positively correlated with IGF-1R (r=0.281, P=0.000 1). There was no significant correlation between IGF-1 and IGF-2R in cancer tissues (P>0.05). Conclusion IGF-1 and IGF-1R may promote the occurrence of colorectal cancer, and IGF-2R may be associated with the progress of colorectal cancer,and obesity is a risk factor for incidence of colorectal cancer.