Vitamin E Supplements in Preventing Cancer in Patients at Risk of Prostate Cancer or Who Have Prostate Cancer

OBJECTIVES:

- Determine the effect of tocopherol supplementation on plasma and urine levels of α-,
γ-, and δ-tocopherols, PSA, and prostaglandin E_2 by comparing the blood and urine
samples collected before and after the supplementation in patients with prostate
cancer.

- Test the hypothesis that the supplementation reduced oxidative and nitrosative stress
by measuring plasma levels of F_2-isoprostane, C-reactive protein, and 3-nitrotyrosine
as well as urinary levels of 8-hydroxy-2-deoxyguanosine (8-OHdG).

- Determine the levels of α-, γ-, and δ-tocopherols in prostate tissues and analyze
immunohistochemically (IHC) for cell proliferation, apoptosis, cyclooxygenase-2,
8-OHdG, and 3-nitropyrosine levels in prostate cancer/tissue slides.

OUTLINE: Patients are randomized into 1 of 3 arms.

- Arm I: Patients receive no supplementation.

- Arm II: Patients receive oral high γ-tocopherol vitamin E supplementation once daily
for 1 week.

- Arm III: Patients receive oral high γ-tocopherol vitamin E supplementation once daily
for 2 weeks.

Blood, urine, and tissue samples are collected periodically and analyzed for
oxidative/nitrosative stress and other markers (i.e., F2-isoprostane, 8-OHdG,
3-nitrotyrosine, prostaglandin E2, C-reactive protein, and PSA), biomarkers in prostate
tumors and nontumorous tissues (i.e., 8-OHdG, 3-nitrotyrosine, and cyclooxygenase-2) by IHC,
and pharmacokinetics by high-performance liquid chromatography.