[Prediction of prognosis of patients with gastrointestinal cancer based on thymidine uptake].

In 173 patients with operable gastric cancer and in 127 patients with colorectal cancer, the relations between thymidine uptake by cancer cells in semi-solid media, their clinico-pathologic features and survival times, were studied. Multivariate analysis using Cox proportional hazard model showed that thymidine uptake is one of the variables most highly correlated with the probability of patient death. Thus, the availability of thymidine uptake information in the perioperative period may be useful for selecting patients who would benefit from more intensive therapy. Thymidine kinase (TK) is the only enzyme by which thymidine is introduced into the DNA metabolism. In 64 specimens, including gastric and colorectal cancers, TK levels in the serum and tumors were measured accordingly. However, there was no correlation between thymidine uptake and the TK levels, suggesting the necessity of measuring thymidine phosphorylase activity as well.