OUTLINE: Patients receive oral green tea extract six times daily for 4 months. Patients with a 50% decline in PSA, complete or partial response, or stable disease after 4 months continue treatment in the absence of disease progression or unacceptable toxicity. Patients with disease progression after 4 months receive no further treatment. Patients are followed every 3 months for 5 years or until disease progression. If disease progression, patients are followed every 6 months for 5 years.