Objective: To evaluate the expression of thymidylate synthase and dihydropyrimidine dehydrogenase in prostate tissue.
Materials and methods: Tissue from 79 patients with localized prostate cancer was used. Thymidylate synthase and dihydropyrimidine dehydrogenase expression were determined semiquantitatively by immunohistochemistry.
Results: Thymidylate synthase and dihydropyrimidine dehydrogenase immunostaining grades of benign tissue were significantly higher than those of cancer tissue (both P < 0.01). Cancer tissue with a primary Gleason grade of > or = 4 expressed a higher thymidylate synthase staining grade than those with a primary Gleason grade of <4 (P < 0.01). Cancer tissue spots from patients treated with neoadjuvant therapy revealed significantly higher thymidylate synthase and dihydropyrimidine dehydrogenase grades than those with no neoadjuvant therapy (P < 0.01).
Conclusion: High thymidylate synthase expression in localized prostate cancer might reflect an aggressive status. High expression in high-grade prostate cancers and prostate cancers after hormonal therapy suggest that thymidylate synthase could be a new therapeutic target for advanced prostate cancer.