Cholecalciferol and Genistein Before Surgery in Treating Patients With Early Stage Prostate Cancer

PRIMARY OBJECTIVES:

I. To determine differences in prostate tissue steady state concentrations of calcitriol in participants treated with a single dose cholecalciferol (200,000 IU) and G-2535 (which provides 600 mg of genistein) and those receiving placebo.

SECONDARY OBJECTIVES:

I. To determine the effect of each intervention arm and resulting prostate tissue levels of calcitriol on down-stream related biomarkers and related mechanistic pathways in blood and tissue.

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

ARM I: Patients receive cholecalciferol orally (PO) on day 1 and genistein PO once daily (QD) on days 1-21 or 1-28. Patients then undergo prostatectomy.

ARM II: Patients receive placebo PO on day 1 and placebo PO QD on days 1-21 or 1-28. Patients then undergo prostatectomy.

Inclusion criteria

• Participants must have microscopic confirmation of adenocarcinoma of the prostate within three months of randomization; clinical stage T1 and T2 a, b, or c are allowed
• Participants' prostate cancer must be confined to the prostate (in the clinical judgment of the treating physician)
• Participants must be candidates for prostatectomy
• Participants must have Eastern Cooperative Oncology Group (ECOG) performance status =<1 (Karnofsky >= 70%)
• White blood cell (WBC) within normal limits
• Platelets >= 100 K/uL
• Hemoglobin >= 10 g/dL
• Thyroid-stimulating hormone (TSH) =< 4.20 uIU/mL
• Free T4 =< 12.5 ng/dL
• Bilirubin within upper limit of normal
• Aspartate aminotransferase (AST) =< 1.5 x upper limit of normal
• Creatinine =< 2.0 mg/dL
• Serum calcium: within institutional normal limits
• Participants must agree to stop taking nonsteroidal anti-inflammatory drugs (NSAIDS) during the course of the study, however, low dose aspirin (< 100 mg/day) will be allowed; no wash out period is required
• Participants must be willing to discontinue consuming soy products and ingesting vitamin supplements while participating in this study
• The effects of cholecalciferol and genistein on the developing human fetus at the recommended therapeutic doses are unknown; for this reason, participants must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) for the duration of study participation
• Participants must have the ability to understand and sign a consent form indicating the investigational nature of the treatment and its potential risks

Exclusion criteria

• Participants may not have received any prior therapy for prostate cancer including: chemotherapy, hormonal therapy, brachytherapy, or external radiation
• Participants may not be receiving concurrent systemic therapy for other cancers
• Participants may not be receiving any other investigational agents
• Participants may not be taking the following p450 inducers and inhibitors: carbamazepine, clarithromycin, fluconazole, fosphenytoin, itraconazole, ketoconazole, phenobarbital, phenytoin, rifabutin, rifampin
• Participants who took finasteride or dutasteride within 6 months of the pre-randomization biopsy, are currently taking finasteride or dutasteride, or are planning on taking these agents during study participation
• Participants with a history of allergic reactions attributed to genistein or placebo, or compounds of similar chemical or biologic composition
• Participants with uncontrolled intercurrent illness including, but not limited to ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements
• Participants requires thyroid replacement therapy; Note: participants with a history of thyroid disease > 5 years ago, with current normal thyroid function, will be considered eligible
• Participant has current, known nephrolithiasis or a history of nephrolithiasis within the past 5 years
• Participant has any history of sarcoidosis