Impact of intratumoral thymidylate synthase expression on prognosis after surgical resection for ampullary carcinoma

Background and Objectives This study evaluated possible prognostic value of expression level of intratumoral thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), and orotate phosphoribosyltransferase (OPRT) in patients with resected ampullary carcinoma. Methods Immunohistochemical staining evaluated intratumoral TS, DPD, and OPRT expression in 52 surgical specimens of patients with ampullary carcinoma. Relationships between clinicopathological factors including intratumoral TS, DPD, or OPRT expressions and survival was evaluated by univariate and multivariate analysis. Results High intratumoral DPD, OPRT, and TS expressions were found in 19 (37%), 30 (58%), and 23 (44%) of cases, respectively. Patients with high TS expression had more advanced‐stage disease than those with low TS expression. Univariate analysis revealed that gender, perineural invasion, lymph node status, UICC pT factor, UICC stage, OPRT expression, and TS expression correlated significantly (P