RATIONALE: Chemoprevention therapy is the use of certain drugs to try to prevent the development of cancer. The use of selenium may be an effective way to prevent prostate cancer in patients who have neoplasia of the prostate. PURPOSE: Randomized phase III trial to study the effectiveness of selenium in preventing prostate cancer in patients who have neoplasia of the prostate.
OBJECTIVES: * Compare the effects of selenium versus placebo on the 3-year incidence rate of prostate cancer in patients with high-grade prostatic intraepithelial neoplasia. * Compare the toxicity of these regimens in these patients. * Compare the effects of these regimens on the rate of increase in prostate-specific antigen (PSA) in these patients. * Compare the effects of these regimens on prostatic cellular proliferation and apoptosis, degradation of basal cell integrity of prostatic ducts, and changes in nuclear chromatin patterns in these patients. OUTLINE: This is a randomized, double-blind, placebo-controlled, multicenter study. Patients are stratified according to age (40-60 vs 61 and over), race (African American vs other), baseline PSA (less than 4 ng/mL vs 4-10 ng/mL), concurrent vitamin E supplementation (yes vs no), and cores obtained from initial biopsy (10 or more vs less than 10). Patients are randomized to 1 of 2 arms. * Arm I: Patients receive oral selenium once daily. * Arm II: Patients receive oral placebo once daily. Treatment in both arms continues for 3 years in the absence of progression to prostate cancer or unacceptable toxicity. Patients are followed every 6 months for 2 years and then annually for 8 years. PROJECTED ACCRUAL: A total of 465 patients will be randomized for this study.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
TRIPLE
Enrollment
619
Randomization between active L-selenomethionine and placebo
Randomization between active L-selenomethionine and placebo
Presence of Carcinoma of the Prostate as Measured by Biopsy
The primary endpoint is biopsy-proven presence/absence of carcinoma of the prostate within 3 years after randomization to treatment. An end-of-study biopsy at 3 years after randomization will be used to determine presence/absence of prostate carcinoma in those patients not previously diagnosed with prostate carcinoma on study. Biopsies performed within ± 90 days of the 3-year anniversary will be considered end-of-study biopsies. Pathologically confirmed presence of prostate carcinoma may be determined at any time during the 3 years and 90 days after randomization, but absence can only be determined by the end-of-study biopsy.
Time frame: 3 years
Number of Patients With Grade 3 Through Grade 5 Adverse Events That Are Related to Study Drug
Adverse Events (AEs) are reported by the NCI Common Terminology Criteria for Adverse Events (CTCAE) version 2.0. For each patient, worst grade of each event type is reported. Grade 3 = Severe, Grade 4 = Life-threatening, Grade 5 = Fatal.
Time frame: 3 months after randomization and then every 3 months for 3 years
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