The role of S100A4 in the progression of human bladder cancer

The calcium-binding protein S100A4 promotes metastasis in several experimental animal models, and S100A4 protein expression is associated with patient outcome in a number of tumor types. In the present study, we studied the S100A4 expression and the clinical importance of protein product (S100A4) in association with patient outcome (n=128) by immunohistochemistry. We demonstrated that positive immunoreactivity of protein S100A4 was detected in 48 (37.3%) of the tumor cases. S100A4 was positively related to staging classification (P < 0.05), with the most significant difference being observed between pTa tumors and those of pT1-pT3 bladder cancer (P < 0.01). Increased S100A4 tended to have a higher risk of tumor metastasis (P = 0.057) or poor longtime survival(P = 0.087). In the subset of grade 2 bladder tumors, induced S100A4 significantly correlated with the occurrence of tumor metastasis or poor patient survival (P < 0.05). These findings overall suggest that S100A4 is associated with tumor recurrence, metastasis and poor overall survival in patients with bladder cancer. A prospective study is required to clarify the potential of the molecular marker in prediction of disease progression.