Correlation between expression levels of thymidine phosphorylase (dThdPase) and clinical features in human gastric carcinoma.
OBJECTIVE
dThdPase (thymidine phosphorylase) is an enzyme that is involved in pyrimidine nucleoside metabolism. It has been recently reported that dThdPase is identical to platelet-derived endothelial cell growth factor. Previous studies demonstrated that the immunohistochemical expression of dThdPase was related with disease progression. The purpose of this study was to examine the expression levels of dThdPase and their prognostic significance in gastric carcinoma, prospectively.


METHODS
We obtained fresh samples (tumors and adjacent normal mucosa) from 263 patients with gastric cancer who underwent gastrectomy between April 1998 and March 2000. dThdPase was analyzed by the enzyme-linked immunosorbent assay method.


RESULTS
The expression levels of dThdPase in tumors (98.4 +/- 62.5 U/mg protein) was significantly higher than that in normal mucosa (46.5 +/- 27.8 U/mg protein) (P < 0.0001). Intratumoral dThdPase levels were significantly higher in Borrmann types II and III macroscopically (P < 0.01), in poorly differentiated type histologically (P < 0.05), and in the tumor-invading serosa (P < 0.001). The expression levels of dThdPase were also significantly higher in tumor tissue from patients with lymph node metastasis (P < 0.01) and in that from patients with lymphatic invasion (P < 0.05). The survival rate of patients with tumor of high dThdPase (> or = 100 U/mg protein) was significantly poorer than that of patients with tumor of low dThdPase (< 100 U/mg protein) (P < 0.05).


CONCLUSIONS
These findings indicate that the measurement of dThdPase may provide useful information for predicting prognosis in gastric carcinomas.
Kimura
Hironobu
H
Department of Surgery, Toyama Prefectural Central Hospital, Toyama, Japan. kimu-chan@mtb.biglobe.ne.jp
Konishi
Kohji
K
Kaji
Masahide
M
Maeda
Kiichi
K
Yabushita
Kazuhisa
K
Miwa
Atsuo
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D013274:Stomach Neoplasms / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D013939:Thymidine Phosphorylase / Q000378:metabolism*
D013939:Thymidine Phosphorylase