[An enzyme involved in pyrimidine catabolism. Increased DPD levels can influence tumor response to 5-fluorouracil-based chemotherapy through increased inactivation of the agent in tumor cells. Increases of the DPD mRNA level in cancerous tissue seem to reflect tumor progression. High DPD mRNA levels in liver metastasis and advanced colorectal cancer may have clinical importance for 5-fluorouracil-based chemosensitivity. (from Ann Surg Oncol 2002;9:599-603) ( NCI )]