Predictive Value of Thymidylate Synthase and Dihydropyrimidine Dehydrogenase Expression in Tumor Tissue, Regarding the Efficacy of Postoperatively Administered UFT (Tegafur+Uracil) in Patients with Non-small Cell Lung Cancer

Background: UFT (tegafur + uracil) has been reported to be effective as an adjuvant in postoperative chemotherapy for non-small cell lung cancer (NSCLC) in a randomized prospective study. Thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) expression were investigated in resected tumors and the relationship between their expression and clinical factors in NSCLC patients was examined. Patients and Methods: Fifty-four NSCLC patients had undergone complete surgical resection and lymph node dissection, and had been administered UFT post-surgery. The TS and DPD expression in the tumor tissues was evaluated by immunohistochemical staining. The relationship between TS and/or DPD expression and clinicopathological factors was examined. Results: There were 38 TS-negative and 16 TS-positive cases, and 22 DPD-negative and 32 DPD-positive cases. There was no significant difference between the patients with TS or DPD and those without TS or DPD in age, gender, histological type or p-stage. The 5-year survival rates of patients positive and negative for TS were 50.0 and 89.5%, while 10-year survival rates were 23.3 and 79.7%, respectively (p