Pyrimidine nucleoside phosphorylase (PyNPase) converts
5'-deoxy-5-fluorouridine to 5'-fluorouracil, which exerts an anticancer effect before being catabolized by
dihydropyrimidine dehydrogenase (DPD). Recently, PyNPase has been shown to be identical to a potent
angiogenic factor,
platelet-derived endothelial cell growth factor. We analyzed the concentration of PyNPase and DPD in 33 patients with
esophageal squamous cell carcinoma in fresh-frozen samples by
enzyme-linked
immunosorbent assay. In addition, we evaluated the clinical significance and prognostic value of PyNPase expression in esophageal
carcinoma. The PyNPase concentration of
tumor tissue was statistically higher than that of normal tissue of the esophagus (248 +/- 146 U/mg
protein vs 73 +/- 63 U/mg
protein, P = 0.0001), whereas DPD showed no difference (90 +/- 62 U/mg
protein vs 88 +/- 62 U/mg
protein, P = 0.825). The ratio of PyNPase to DPD of
tumor tissue was statistically higher than that of normal tissue of the esophagus (3.3 vs 0.95, P = 0.0001). There were no significant differences between the group with high
tumor to normal tissue ratios of PyNPase concentration and the low-ratio group in terms of the
tumor length, depth,
lymph node metastasis, lymph vessel invasion, vascular invasion, stage and survival. In conclusion,
5'-deoxy-5-fluorouridine may be effective on esophageal
carcinoma and PyNPase concentration in esophageal
carcinoma may not be a useful prognostic marker for patients with
esophageal squamous cell carcinoma.