The effects of vitamin E status on the risk of prostate cancer may be modulated by genetic differences in enzymes that control oxidative stress, according to new research.
Researchers investigated the associations between serum vitamin E
(alpha- and gamma- tocopherols), their effect on oxidative stress
regulation, and the risk of prostate cancer.
The researchers found that patients with prostate cancer had lower serum alpha- tocopherol levels than non-cancer controls. They studied the interaction of genetic differences (polymorphisms) in four enzymes, including myeloperoxidase (MPO), with serum alpha- and gamma- tocopherol levels and prostate cancer risk in 18.314 heavy smokers and asbestos-exposed workers.
The authors reported that among current smokers, higher serum alpha-tocopherol levels were associated with lower cancer risk, reporting a 34 per cent decrease in cancer risk between highest and lowest groups of vitamin E status.
Genetic variations in the four enzymes were associated with nearly two-fold increase in the risk of agressive prostate cancer among current somkers with low serum alpha-tocopherol levels.
They noted that polymorphisms in genes controlling the enzyme myeloperoxidase may alter aggressive prostate cancer risk.
The researchers found that higher levels of serum alpha-tocopherol may be particularly import among men with certain, high risk, myeloperoxidase genotypes to reduce the risk of prostate cancer.