Trial Information

Phase II Chemoprevention Trial of Selenium and Prostate Cancer (Watchful Waiting With Selenium Trial)

OBJECTIVES:

- To investigate the ability of selenium to prevent progression in patients with
adenocarcinoma of the prostate.

- To investigate the ability of selenium to effectively modulate biomarkers of prostate
cancer.

- To determine if selenium modifies the progression of prostate cancer based on an
analysis of initial biopsy, subsequent blood biomarkers, and urological symptoms.

- To further establish the safety of chronic supplementation with selenium in these
patients.

OUTLINE: Patients are stratified according to Gleason score (low vs moderate). Patients are
randomized to 1 of 3 treatment arms.

- Arm I: Patients receive oral placebo once daily for 48 months in the absence of disease
progression or unacceptable toxicity.

- Arm II: Patients receive low-dose oral selenium once daily for 48 months in the absence
of disease progression or unacceptable toxicity.

- Arm III: Patients receive high-dose oral selenium once daily for 48 months in the
absence of disease progression or unacceptable toxicity.

Blood and tissue samples are collected periodically for biomarker laboratory studies. Blood
samples are analyzed for levels of prostate-specific antigen, chromogranin A, alkaline
phosphatase, alpha tocopherol, lycopene, and other vitamins; levels of selenium by atomic
absorption spectrometry; and oxidative damage to DNA. Tissue samples are analyzed for levels
of Bcl-2, p53, Ki-67, thioredoxin reductase, thioredoxin, and glutathione peroxidase by
immunohistochemistry and for apoptotic index by TUNEL assay.

Patients complete urological symptom questionnaires and other questionnaires periodically.