Fish Oil and Green Tea Extract in Preventing Prostate Cancer in Patients Who Are at Risk for Developing Prostate Cancer

OBJECTIVES: * Determine the cancer preventing effects of fish oil supplementation and green tea extract use on markers of alteration in lipid metabolism in prostate tissue samples. OUTLINE: This is a randomized, double-blind, placebo-controlled study. Patients are stratified according to age (under 65 vs 65 and over). Patients are randomized to 1 of 4 treatment arms. * Arm I: Patients receive oral fish oil three times daily and oral green tea extract twice daily. * Arm II: Patients receive an oil placebo three times daily and oral green tea extract twice daily. * Arm III: Patients receive oral fish oil three times daily and a placebo twice daily. * Arm IV: Patients receive an oil placebo three times daily and another placebo twice daily. Treatment in one of the above-listed arms continues for up to 20 weeks in the absence of disease progression or unacceptable toxicity. All patients undergo a prostate biopsy on the last day of study treatment. After completion of study treatment, patients receive a follow-up phone call at/around 30 days later. PROJECTED ACCRUAL: A total of 144 patients will be accrued for this study.