Manganese superoxide dismutase polymorphism, prediagnostic antioxidant status, and risk of clinical significant prostate cancer

Oxidative stress may enhance prostatic carcinogenesis. A polymorphism [valine (V) ! alanine (A)] of manganese superoxide dismutase (MnSOD), the primary antioxidant enzyme in mitochondria, has been recently associated with prostate cancer. We examined the relationship between prostate cancer and the MnSOD polymorphism and its interactions with baseline plasma antioxidant levels (selenium, lycopene, and a-tocopherol) and h-carotene treatment among 567 cases and 764 controls nested in the prospective Physicians ’ Health Study. We found little overall association between MnSOD polymorphism and prostate cancer risk; however, this polymorphism significantly modi-fied risk of prostate cancer associated with prediagnostic plasma antioxidants (P interaction < _ 0.05). Among men with th