• Effects of selenium on antioxidant enzyme activities at 1 and 6 months after completion of study treatment [ Designated as safety issue: No ]
• Threshold effect among patients with low baseline levels of selenium at 1 and 6 months after completion of study treatment [ Designated as safety issue: No ]

• Effects of selenium on antioxidant enzyme activities at 1 and 6 months after completion of study treatment
• Threshold effect among patients with low baseline levels of selenium at 1 and 6 months after completion of study treatment

RATIONALE: The use of nutritional supplements, such as selenium, may stop prostate cancer from growing. Internal radiation, such as brachytherapy, uses radioactive material placed directly into or near a tumor to kill tumor cells. Giving selenium before brachytherapy may be an effective treatment for prostate cancer.

PURPOSE: This randomized phase I trial is studying selenium to see how well it works compared to placebo in treating patients who are undergoing brachytherapy for stage I or stage II prostate cancer.

OBJECTIVES:

Primary

• Compare the effects of selenium vs placebo on tissue biomarkers of prostate cancer susceptibility, using tissue samples from biopsies before and after treatment, in patients undergoing brachytherapy for stage I or II prostate cancer.

Secondary

• Determine the effects of selenium on antioxidant enzyme activities in these patients.
• Determine, preliminarily, whether there is a threshold effect among patients with low baseline levels of selenium treated with this drug.

OUTLINE: Patients are randomized to 1 of 2 treatment arms.

• Arm I: Patients receive oral selenium for 3-6 weeks. Patients then undergo brachytherapy.
• Arm II: Patients receive oral placebo for 3-6 weeks. Patients then undergo brachytherapy.

After completion of study treatment, patients are followed at 1 and 6 months.

• Dietary Supplement: selenium
• Other: placebo

• Experimental: Patients receive oral selenium for 3-6 weeks.
• Placebo Comparator: Patients receive oral placebo for 3-6 weeks.

DISEASE CHARACTERISTICS:

• Histologically confirmed adenocarcinoma of the prostate

  • Must have undergone ≥ a sextant biopsy
  • Clinical stage T1a-T2a disease
• Gleason score < 8
• Prostate-specific antigen < 20 ng/mL

PATIENT CHARACTERISTICS:

Age

• Not specified

Performance status

• Not specified

Life expectancy

• More than 5 years

Hematopoietic

• Not specified

Hepatic

• Not specified

Renal

• Not specified

Other

• No other prior malignancy except nonmelanoma skin cancer

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Not specified

Chemotherapy

• Not specified

Endocrine therapy

• No prior hormonal therapy

Radiotherapy

• No prior radiotherapy

Surgery

• Not specified

Other

• More than 30 days since prior and no concurrent participation in another clinical trial involving a medical, surgical, nutritional, or lifestyle intervention (e.g., dietary modification or exercise)
• No selenium at doses > 50 mcg/day as a dietary supplement, including multivitamin supplements