Background: High expression of PyNPase (pyrimidine nucleoside phosphorylase) and DPD (dihydropyrimidine dehydrogenase) in breast cancer has been reported. Breast cancer patients with high expression of PyNPase reportedly have a poor prognosis.
Methods: We evaluated the relationship between postoperative prognosis, and clinicopathological factors including HER2 expression and the levels of PyNPase and DPD in breast cancer. PyNPase and DPD levels in tumors and nontumorous tissues were examined by enzyme-linked immunosorbent assay (ELISA).
Results: PyNPase and DPD levels in tumors were significantly higher than in non-tumorous tissues (p<0.001). The DPD levels in tumors associated with> or =2+expression of HER2 were significantly higher than in others (p=0.014). Disease-free survival in patients with<100 U/mg protein of PyNPase levels or<4 of PyNPase/DPD ratio was significantly better compared with others (p=0.022, p=0.014).
Conclusion: PyNPase/DPD ratio may be a new prognostic marker in breast cancer.