Selenomethionine and Finasteride Before Surgery or Radiation Therapy in Treating Patients With Stage I or Stage II Prostate Cancer

RATIONALE: Selenomethionine may slow the growth of prostate cancer. Testosterone can cause the growth of prostate cancer cells. Finasteride may fight prostate cancer by lowering the amount of testosterone the body makes. Giving selenomethionine together with finasteride before surgery or radiation therapy may be an effective treatment for prostate cancer. PURPOSE: This randomized phase II trial is studying how well selenomethionine and finasteride work when given before surgery or radiation therapy in treating patients with stage I or stage II prostate cancer.

OBJECTIVES: Primary * To investigate the effects of selenomethionine and/or finasteride on key androgen receptor signaling biomarkers (prostate-specific antigen, kallikrein 2, and NKX3.1) in prostate tissue samples from patients with stage I or II prostate cancer. Secondary * To analyze the effects of selenomethionine and/or finasteride on apoptosis induction in benign prostate tissue samples from these patients. Tertiary * To determine whether responsiveness to selenomethionine and/or finasteride is related to the level of Prx1 in prostate cancer cells. OUTLINE: Patients are randomized to 1 of 4 treatment arms. * Arm I: Patients receive oral selenomethionine and oral finasteride once daily for 4-5 weeks. Patients then undergo prostatectomy or brachytherapy. * Arm II: Patients receive oral placebo and oral finasteride once daily for 4-5 weeks. Patients then undergo prostatectomy or brachytherapy. * Arm III: Patients receive oral selenomethionine and oral placebo once daily for 4-5 weeks. Patients then undergo prostatectomy or brachytherapy. * Arm IV: Patients receive two oral placebos once daily for 4-5 weeks. Patients then undergo prostatectomy or brachytherapy. Blood samples are collected at baseline and on the day of prostatectomy or brachytherapy. Samples are analyzed for testosterone and 5-α-dihydrotestosterone levels by capillary gas chromatography-mass spectrometry; genetic polymorphisms in the type 2 5-α reductase gene by PCR and sequencing analyses; and selenium levels by atomic absorption spectrophotometry. Additional blood samples will be stored for future analysis of alpha and gamma tocopherol, lycopene, and other vitamin levels. Toenail samples are also collected to provide an indicator of long-term selenium status. Prostate tissue samples are collected during and after prostatectomy or prior to brachytherapy. Samples are analyzed for expression of biomarkers (e.g., prostate-specific antigen, kallikrein 2, and NKX 3.1) by quantitative RT-PCR and apoptosis by TUNEL assay, immunohistochemistry, and ELISA.