RESUMO
BACKGROUND: Quinine oxidoreductase 1 (NQO1) plays a vital role in protecting normal cells against oxidative damage and electrophilic attack. It is highly expressed in many solid tumors, suggesting a role in cancer development and progression. However, the role of NQO1 in gastric cancer and its effect on cancer development and prognosis have not been fully investigated. AIM: To investigate the clinical relevance of NQO1 protein expression in gastric cancer and to explore the potential of NQO1 to serve as a prognostic biomarker and therapeutic target. METHODS: In this retrospective study, gastric cancer specimens of 175 patients who were treated between 1995 and 2011 were subjected to immunohistochemistry analyses for NQO1. The correlation of NQO1 expression with gastric cancer prognosis and clinical and pathological parameters was investigated. RESULTS: NQO1 protein was overexpressed in 59.43% (104/175) of the analyzed samples. Overexpression of NQO1 was associated with a significantly inferior prognosis. In addition, multivariate analysis suggested that NQO1 overexpression, along with tumor stage and patient age, are prominent prognostic biomarkers for gastric cancer. Moreover, NQO1 overexpression was correlated to a better response to 5-fluorouracil (5-FU)-based adjuvant chemotherapy. CONCLUSION: NQO1 overexpression is associated with a significantly poor prognosis and better response to 5-FU in patients with gastric cancer. These findings are relevant for improving therapeutic approaches for gastric cancer patients.