Prognostic significance of oxidative DNA damage evaluated by 8-hydroxy-2′-deoxyguanosine in patients undergoing radical nephrectomy for renal cell carcinoma

To determine whether the degree of oxidative DNA damage in renal cell carcinoma (RCC) can be used as a useful prognostic predictor for patients who undergo radical nephrectomy.We measured 8-hydroxy-2′-deoxyguanosine (8-OHdG), one of the most commonly used markers for evaluating oxidative stress, in DNA isolated from 72 RCC specimens, as well as adjacent normal kidney tissue using a quantitative sandwich enzyme-linked immunosorbent assay.The mean value of 8-OHdG in RCC was significantly greater than that in the adjacent normal tissue. The level of 8-OHdG in RCC compared with that in normal tissue (8-OHdG ratio) was significantly associated with other prognostic parameters, including mode of detection, maximal tumor size, distant metastasis, pathologic stage, tumor grade, and microscopic venous invasion. Furthermore, cancer-specific survival in patients with an elevated 8-OHdG ratio was significantly lower than that in patients with a normal 8-OHdG ratio; however, multivariate analysis using a Cox proportional hazards model showed that maximal tumor size and distant metastasis could be used as independent predictors of cancer-related death.These findings suggest that despite the lack of independent significance, the 8-OHdG ratio could be a useful prognostic indicator for patients with RCC; therefore, careful follow-up should be considered in those with an elevated 8-OHdG ratio. [Copyright &y& Elsevier]