Expression of thymidylate synthase in cancer of the ampulla of Vater

The clinical and therapeutic significance of thymidylate synthase (TS) in cancers of the ampulla of Vater have not yet been reported. We immunohistochemically evaluated TS expression in 33 ampullary cancers using an anti-TS antibody. TS expression, clinicopathologic variables, and survival rates were examined and the correlations between these parameters were identified. Fifteen patients were found to express high levels of TS (high TS group), while 18 patients expressed low levels of TS (low TS group). No significant difference was found between TS expression and clinicopathologic factors. Univariate and multivariate analysis revealed that lymph node metastasis and pancreatic invasion are important variables for independently predicting postoperative survival. Although TS expression was not identified as an important factor for postoperative survival, recurrent cases in patients with chemotherapy existed only in the high TS group. In the present: study, it was found that TS expression itself in cancers of the ampulla of Vater has no impact in predicting the prognosis of ampullary cancers, but a chemotherapeutic benefit of evaluating TS expression may exist.