The aim of the present study was to investigate the clinicopathologic/prognostic significance of
thymidylate synthase (TS),
orotate phosphoribosyltransferase (OPRT), and
thymidine phosphorylase (TP)
proteins in postoperative
non-small cell lung cancer (NSCLC) patients. Microarray slides from a set of 178 NSCLC patients were used for the detection of TS, OPRT, and TP expression by immunohistochemistry. The correlation between clinicopathologic factors and
protein expression of three
proteins was analyzed. Ninety seven
carcinomas (57.4%) were TS-positive, 90
carcinomas (53.9%) were OPRT-positive, and 102
carcinomas (69.4%) were TP-positive. Compared with the TS-positive patients, the overall survival (OS) was significantly lower in the TS-negative patients (hazard ratio [HR] =1.766, 95% confidence interval [CI] =1.212-2.573, P=0.003). Significant differences between TS-positive and TS-negative patients was also observed in the following stratified analyses: 1)
adenocarcinoma subgroup (HR =2.079, 95% CI =1.235-3.500, P=0.006); 2) less than 60-year-old subgroup (HR =1.890, 95% CI =1.061-3.366, P=0.031); 3) stage II/III subgroup (HR =1.594, 95% CI =1.036-2.453, P=0.034); and 4) surgery plus adjuvant
therapy subgroup (HR =1.976, 95% CI =1.226-3.185, P=0.005). However, the OS was not significantly correlated with OPRT or TP
protein expression. This study demonstrates that the TS level in
tumor tissues may be a useful marker to predict the postoperative OS in NSCLC patients.