The relationship between survival and the expression of dihydropyrimidine dehydrogenase in patients with colorectal cancer

Dihydropyrimidine dehydrogenase (DPD) is considered to be a key enzyme affecting the prognosis for patients with colorectal cancer. We investigated whether a correlation exists between the expression of DPD and survival in patients with colorectal cancer. The present study was designed to quantify the DPD level using an enzyme-linked immunosorbent assay in tumors and normal tissue specimens obtained from 22 colorectal cancer patients. There were no significant differences in the preoperative features, neither in the intra- and post-operative findings of patients between the high DPD and low DPD groups in tumor tissue. In patients showing an expression of DPD in tumor tissue, the overall survival in the low DPD group tended to be longer than that in the high DPD group (P=0.076). In contrast, in patients showing an expression of DPD in normal tissue, no significant difference was observed in the overall survival between the high DPD and low DPD groups (P=0.358). In patients showing an expression of DPD in tumor tissue, the disease-free survival in the low DPD group was longer than that in the high DPD group (P=0.046), whereas in patients showing an expression of DPD in normal tissue, no significant difference was seen in the disease-free survival between the high DPD and low DPD groups (P=0.473). There tended to be a correlation between the DPD expression in tumor tissue and that in adjacent normal tissue (R=0.390, P=0.073). Based on these findings, we demonstrated the importance of DPD expression in tumor tissue as a prognostic factor in patients with colorectal cancer.