Expression of Thymidylate Synthase and Thymidine Phosphorylase in Recurrence and Survival Rates of Advanced Gastric Cancer

Gastric Cancer. 1999 Nov;2(3):165-172. doi: 10.1007/s101200050041.

Abstract

BACKGROUND: The immunohistochemical expression of thymidylate synthase (TS) and thymidine phosphorylase (TP) was examined in a comparative study of the recurrence rates and prognoses of patients with advanced gastric cancer at the same stage.METHODS: We examined the resected specimens of 67 patients with stage IIIB gastric cancer (pT3, pN2, M0) under 70 years of age who had undergone curative gastrectomy followed by adjuvant chemotherapy with 5-fluoropyrimidines. Paraffin sections of the resected specimens were stained with human anti-TS polyclonal and anti-TP monoclonal antibodies by the avidin-biotin-peroxidase complex (ABC) method.RESULTS: The overall expression of TS and TP was 45.4% and 43.4%, respectively. The postoperative survival curve for the TS-positive group was significantly depressed compared with that for the TS-negative group ( P = 0.0480). The survival curves for TP-positive and TP-negative groups did not show any difference. In regard to the combination of TS and TP expression, the best survival curve was obtained for the TS(-)/TP(+) group, followed by those for the TS(-)/TP(-), TS(+)/TP(-), and TS(+)/TP(+) groups in descending order. With regard to the recurrence site, there was no significant difference in peritoneal recurrence in relation to positivity for TS or TP. Lymph node recurrence, however, was significantly higher in the TS-positive and TP-positive groups, with P-values being 0.0466 and 0.0058, respectively, versus the corresponding negative groups. The incidence of hepatic recurrence was higher in the TP-positive group than in the TP-negative group ( P = 0.0910). As for the total doses of 5-fluoropyrimidines given, more favorable survival curves were obtained for the high dose of negative TS and TP groups, but no significant differences were observed in their positivities.CONCLUSION: The expressions of TS and TP showed different characteristics in overall survival and recurrence rate or site. They should be used for predicting prognosis in comprehension on their properties.