IGF2/IGF2R expression in urothelial bladder cancer and its implications for tumor recurrence and prognosis

Insulin-like growth factor 2 (IGF2) is a secreted growth factor which has growth-regulating, insulin-like and mitogenic activities. Insulin-like growth factor 2 receptor (IGF2R) is a multifunctional receptor functioning by binding with many ligands such as IGF2, growth factor-beta and pro-cathepsin D, etc. To evaluate the expression and clinical significance of IGF2 and IGF2R in urothelial bladder cancer, 126 cases were collected in validation cohort for detection of IGF2 and IGF2R by immunohistochemistry. Moreover, the correlation of IGF2/IGF2R with clinicopathological factors was evaluated with Chi-square test. The association with recurrence and overall survival rate was analyzed with univariate and multivariate analysis. Consequently, the association between IGF2 and tumor recurrence or prognosis was not observed in our study. However, IGF2R overexpression was demonstrated to be significantly correlated with tumor recurrence (P = 0.006) and prognosis (P = 0.019). High expression of IGF2R was identified as an independent indicator of lower recurrence (P = 0.008) and more favorable prognosis (P = 0.010). In conclusion, IGF2R high expression was significantly associated with lower recurrence and better prognosis, suggesting that IGF2R could be considered as a suppressor of bladder cancer by reducing the recurrence rate and improving survival time.