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