Analysis of the mRNA expression levels of thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD) and orotate phosphoribosyl transferase (OPRT) in liver metastases from colorectal cancer.

BACKGROUND/AIMS: We measured the mRNA expression levels of thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD) and orotate phosphoribosyl transferase (OPRT) in liver metastases from colorectal cancer and retrospectively analyzed their association with other clinicopathological factors and the prognosis of these patients. METHODOLOGY: The study involved 55 patients of colorectal cancer with liver metastasis who underwent surgery at our department between February 1988 and April 2003. RESULTS: Analysis of the mRNA expression levels of each of the aforementioned enzymes in the liver metastases revealed no significant differences in the mRNA expression levels of the enzymes depending on the timing of development of the liver metastasis, histological type of the cancer, or the patient gender. In the analysis of the survival period, no association was observed between the survival prognosis and the mRNA expression level of DPD or OPRT in the liver metastases; on the other hand, the prognosis was better in the group showing low TS mRNA expression (median survival period: 3.77 years) than in the group showing high TS mRNA expression (median survival period: 2.39 years) (p=0.0134). CONCLUSIONS: These results suggest that the mRNA expression level of TS in the liver metastases in colorectal cancer patients is a useful prognostic indicator.