Manganese superoxide dismutase and glutathione peroxidase as prognostic markers in patients with buccal mucosal squamous cell carcinomas

Background. We investigated the relationship of the immunohistochemical expression status of manganese superoxide dismutase (MnSOD), catalase, glutathione peroxi- dase (GPx), and myeloperoxidase (MPO) in buccal mucosal squamous cell carcinoma (SCC) with clinicopathologic parame- ters and prognosis. Methods. The expression status of MnSOD, GPx, catalase, and MPO was evaluated by immunohistochemistry in a series of 216 surgically resected buccal mucosal SCC specimens, using tissue microarray slides. Results. MnSOD, GPx, catalase, and MPO were commonly expressed in buccal mucosal SCC. The high expression level of MnSOD was associated with better disease-specific survival (p ¼ .009), especially for patients in moderate or poor cell differentiation (p ¼ .045), pathologic stage I (p ¼ .002) and postoperative radiotherapy (p ¼ .048). The high expres- sion level of GPx was also correlated with better disease-specific survival (p ¼ .042), especially for patients in pathologic stage IV (p ¼ .010) and postoperative radiotherapy (p ¼ .018). Conclusions. MnSOD and GPx are significant prognostic factors for favorable survival in patients with buccal mucosal SCC. V C 2011 Wiley Periodicals, Inc. Head Neck 33: 1606- 1615, 2011