RT Journal Article SR Electronic T1 The Relationship between Clinicopathological Factors and the Reduction of Pyrimidine Nucleoside Phosphorylase Activity after Preoperative Administration of 5′-Deoxy-5-fluorouridine JF Anticancer Research JO Anticancer Res FD International Institute of Anticancer Research SP 3207 OP 3211 VO 30 IS 8 A1 TERUKO HONDA A1 HIROYUKI INAGAWA A1 TAKASHI NISHIZAWA A1 HIROSHI YOSHIMURA A1 ISAMU YAMAMOTO A1 GEN-ICHIRO SOMA YR 2010 UL http://ar.iiarjournals.org/content/30/8/3207.abstract AB Aim: The response to fluoropyrimidine chemotherapeutic drugs is different in individual tumors. Predictive biomarkers of antitumor effects by these drugs are unknown. 5′-Deoxy-5-fluorouridine (5′-DFUR), a fluoro-pyrimidine chemotherapeutic drug, is converted to 5-fluorouracil (5-FU) by pyrimidine nucleoside phosphorylase (PyNPase). It is suggested that 5′-DFUR will efficiently exert antitumor effects via PyNPase in tumor tissues. The change of PyNPase activity in tumor tissues following 5′-DFUR administration may reflect antitumor effects, and may be useful for detecting predictive factors of antitumor effects. The aim of this study was to search for predictive factors of antitumor effects by analyzing the relationship between clinicopathological factors and the change of PyNPase activity in colorectal tumor tissues after preoperative 5′-DFUR administration. Patients and Methods: PyNPase activity in colorectal tissues from 45 patients with colorectal tumors was measured using an ELISA method. Results: The reduction rate of PyNPase activity in colorectal tumor tissues after preoperative 5′-DFUR administration was correlated with significant differences in lymphatic invasion, stage, and histologic classification. It is suggested that lymphatic invasion, stage (distant metastasis), and histologic classification may be predictive factors for evaluating antitumor effects and selecting 5-FU-based chemotherapeutic drugs for patients with colorectal tumors.