[Significance of tissue thymidine phosphorylase and dihydropyrimidine dehydrogenase activities in ovarian cancer].

Thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) are important enzymes in the pyrimidine salvage pathway. In the meantime, TP and DPD are a converting enzyme of 5'-DFUR to 5-FU and the major catabolic enzyme of 5-FU, respectively. Because little is known about their protein expressions in ovarian cancers, we investigated TP and DPD protein expressions quantitatively in 24 ovarian cancers and their normal counterparts by ELISA. Higher TP expression was observed in ovarian cancers than in normal ovaries. The higher expression was also correlated with the histological grade and clinical stage. No relation was observed between the expression of DPD and the clinical and pathological parameters. The higher TP/DPD ratio, which appears to be a predictor of 5-fluorouracil sensitivity, was observed in ovarian cancers than in normal counterparts. In univariate analysis, a higher TP/DPD ratio was found to be a predictor of progression-free survival in ovarian cancer patients. This would suggest that capecitabine and 5'-DFUR are potential candidates for ovarian cancer chemotherapy.