[Expression of thymidine phosphorylase in human colorectal carcinoma and its clinical significance]

Angiogenesis has been well known to be a factor related to the tumor growth and metastasis. Recent studies have reported that thymidine phosphorylase (TP) is identical with platelet-derived endothelial cell growth factor. It not only plays a role in the induction of the tumor angiogenesis, but also enhances the chemotherapeutical sensitivity of the tumor cells to prodrug of 5-fluorouracil. However, until now, the complete identity of view about the function of TP expression in colorectal carcinoma and its prognostic significance has not been reached. The present study was to explore the TP expression level in human colorectal carcinoma and its clinical significance.

Seventy archived samples of the patients with colorectal carcinoma were detected by immunohistochemical staining. These patients had undergone radical surgical treatment at the First Hospital of Xi'an Jiaotong University and had been followed up for 5 years after operation.

TP expression was predominantly observed in the cytoplasm of the tumor cells. The positive rate was 57.14%(40/70). TP expression levels in the patients with different Dukes, stages and histopathological grades showed obvious difference (P=0.007 and 0.002, respectively). By Kaplan-Meier methods, the survival of TP positive expression group was shorter than that of TP negative expression group, and the five-year survival rates of TP positive expression group and TP negative expression group were 33.33% and 73.33% (P=0.000). The results indicated that the prognosis of the patients with TP positive expression was poorer than that of patients with TP negative expression.

These findings suggest that TP expression might be one of the important prognostic indicators for colorectal carcinoma patients, and TP detection in colorectal carcinoma patients might served as a parameter for designing therapeutic schedule and choosing prodrug of 5-fluorouracil.