Superoxide dismutase 2 expression can predict prognosis of renal cell carcinoma patients

BACKGROUND AND OBJECTIVE: Renal cell carcinoma (RCC) is the urological malignancy with the highest mortality rate and is increasing in incidence. The prognostic and predictive biomarkers are highly desired. This study aims to investigate the significance of superoxide dismutase 2 (SOD2) as a clinical biomarker in patients with renal cell carcinomas. METHODS: A cohort of 97 patients with RCC was analyzed retrospectively using various clinical parameters and SOD2 expression by immunohistochemistry. RESULTS: Cases with stronger SOD2 positivity of the tumor in comparison to the adjacent normal renal tubule by immunohistochemistry were categorized as high SOD2 and were associated with worse overall survivals (p = 0.005). In particular, in cases with metastatic RCC, high SOD2 expression in the tumors was significantly associated with a worse overall survival (p = 0.001), and the maximum critical risk. Treatment with current molecular targeting therapies did not improve the prognoses of cases with metastatic or recurrent RCC. CONCLUSIONS: High SOD2 expression can be predictive of a poor clinical outcome and be clinically useful in the follow-up of metastatic RCC. Therapeutics for metastatic RCCs require further improvement, such as supplementary administration of agents targeting mitochondrial SOD2.