Significance of thymidine phosphorylase in HCC with chronic liver disease for long-term postoperative recurrence

Background and Objectives: Little is known about the significance of thymidine phosphorylase (TP) levels in HCC. The authors investigated the TP activity of HCC and adjacent normal liver tissue in 70 HCC patients, and the prognostic significance of the TP levels. Methods: We obtained fresh samples (tumors with adjacent normal tissues) from 70 patients with HCC who have undergone curative hepatic resection. The levels of TP activity in unfixed, fresh, frozen HCC tissue, together with adjacent normal liver tissue specimens, were determined by the enzyme-linked immunosorbent assay (ELISA) method. Results: The mean TP activity in HCC was approximately 1.5-fold higher than that in adjacent liver tissues (P = 0.0013). Disease-free survival rates for patients with low and high TP levels in HCC were not significantly different. Although disease-free survival rates for low and high TP levels in adjacent normal liver tissue were also not significantly different, disease-free survival for patients with low and high TP levels in adjacent normal liver tissue, excluding cases of postoperative recurrence within 700 days of hepatectomy, showed a significant difference (P=0.0494). The group with high TP activity in adjacent liver tissue showed more frequent postoperative recurrence in the long-term than that with low TP activity. Conclusions: Measurement of TP activity of adjacent normal liver tissue to HCC may allow us to predict metachronous long-term postoperative recurrence.