Oxidative DNA damage in patients with prostate cancer and its response to treatment

We evaluated the significance of oxidative DNA damage in patients with prostate cancer based on the measurement of urinary 8-OHdG (8-hydroxy-2'-deoxyguanosine) and analyzed changes in urinary 8-OHdG before and after initial treatment.

A total of 82 patients with prostate cancer were included in this study. Of these 82 patients 42 underwent radical prostatectomy and the remaining 40 received hormonal therapy as initial treatment. Urinary 8-OHdG and creatinine (Cr), and serum prostate specific antigen (PSA) in these 82 patients were assessed before and 2 months after the initiation of treatment.

The ratio of urinary 8-OHdG-to-Cr (8-OHdG/Cr) in patients with prostate cancer was significantly higher than in age matched healthy controls. Only age was significantly associated with 8-OHdG/Cr in prostate cancer cases among several clinicopathological factors, including serum PSA clinical T stage, metastasis and Gleason score. There was no significant difference in urinary 8-OHdG/Cr in 42 patients before and after radical prostatectomy, while urinary 8-OHdG/Cr in 40 patients after hormonal therapy was significantly lower than before hormonal therapy. In addition, changes in PSA after initial treatment were not related to changes in urinary 8-OHdG/Cr in either treatment group.

These findings suggest that oxidative stress may be involved in an early event in prostate cancer development and androgen suppression is capable of decreasing oxidative stress. Accordingly androgen withdrawal therapy combined with antioxidative agents may inhibit the progression of prostate cancer.