Calcitriol and Dexamethasone Before Radical Prostatectomy in Treating Patients With Localized Adenocarcinoma (Cancer) of the Prostate

OBJECTIVES:

- Determine the effect of calcitriol and dexamethasone before radical prostatectomy on
tumor vessel density in patients with localized adenocarcinoma of the prostate.

- Determine the effect of this regimen on the extent of prostatic intraepithelial
neoplasia in these patients.

- Determine the effect of this regimen on the expression of apoptosis markers, p21, p27,
prostate-specific antigen (PSA), prostate-specific membrane antigen, and VDR expression
in tumor-associated vascular endothelial cells and endothelium derived from
normal-appearing prostate and tumor in these patients.

- Determine the acute effects of this regimen on serum PSA in these patients.

- Determine the toxicity of this regimen in these patients.

OUTLINE: This is a two-stage, randomized, pilot study.

- Stage 1: Patients are randomized to 1 of 2 treatment arms.

- Arm I: Patients receive oral dexamethasone once daily on days 1-4 and oral
calcitriol once daily on days 2-4 weekly for 4 weeks before surgery. Within 48
hours of the last dose, patients undergo radical prostatectomy.

- Arm II: Patients receive no study drugs, but undergo radical prostatectomy.

- Stage 2: If sufficient activity is seen with the dexamethasone and calcitriol regimen
in stage 1, the study is expanded and additional patients are randomized to 1 of 4
treatment arms.

- Arm I: Patients receive dexamethasone and calcitriol as in stage 1, arm I.

- Arm II: Patients receive oral dexamethasone once daily on days 1-4.

- Arm III: Patients receive oral calcitriol once daily on days 2-4.

- Arm IV: Patients undergo radical prostatectomy as in stage 1, arm II. In arms I,
II, and III, patients undergo radical prostatectomy as in stage 1, arm I.

Patients are followed at 1, 3, and 12 months.

PROJECTED ACCRUAL: A total of 20-80 patients (20 for stage 1 [10 per treatment arm] and 60
for stage 2) will be accrued for this study within 2 years.

DISEASE CHARACTERISTICS:

- Histologically confirmed adenocarcinoma of the prostate

- Organ-confined disease

- cT1, cT2, or cT3 tumors

- Patients with cT1 tumors are eligible if ≥ 1 core biopsies have ≥ 50% of
the tumor OR if 50% of the cores examined contain the tumor

- No small cell carcinoma of the prostate

- Scheduled for radical prostatectomy

PATIENT CHARACTERISTICS:

Age

- 18 and over

Performance status

- Not specified

Life expectancy

- Not specified

Hematopoietic

- Platelet count ≥ 100,000/mm^3

- WBC ≥ 3,500/mm^3

Hepatic

- ALT and AST ≤ 4 times normal

- Bilirubin ≤ 2 mg/dL

Renal

- Creatinine ≤ 2 times upper limit of normal

- Calcium ≤ 10.5 mg/dL

- No detectable renal stones by CT scan or ultrasound

Other

- No history of diabetes mellitus requiring pharmacotherapy

PRIOR CONCURRENT THERAPY:

Biologic therapy

- Not specified

Chemotherapy

- Not specified

Endocrine therapy

- More than 5 years since prior antiestrogens, antiandrogens, luteinizing
hormone-releasing hormone agonists, estrogen, or progestational agents

Radiotherapy

- Not specified

Surgery

- See Disease Characteristics

- No prior nephrectomy

- No prior prostatic surgery

- No prior cryotherapy or transurethral resection of the prostate