Calcitriol in Preventing Prostate Cancer in Patients With Prostatic Intraepithelial Neoplasia

You may be eligible if

• DISEASE CHARACTERISTICS:
• Histologically confirmed high-grade prostatic intraepithelial neoplasia
• * Diagnosed within the past 6 months
• No evidence of prostate cancer within the past 6 months
• No evidence of palpable nodules on digital rectal exam
• Prostate specific antigen ≤ 10 ng/mL within the past 3 months
• PATIENT CHARACTERISTICS:
• Age
• 18 and over
• Performance status
• ECOG 0-1
• Life expectancy
• Not specified
• Hematopoietic
• Absolute neutrophil count ≥ 1,500/mm\^3
• Platelet count ≥ 100,000/mm\^3
• Hepatic
• SGOT and SGPT ≤ 1.5 times upper limit of normal
• Renal
• No uncontrolled renal failure
• No cancer-related hypercalcemia or kidney stones within the past 5 years
• Cardiovascular
• No uncontrolled coronary artery disease
• No uncontrolled congestive heart failure
• Other
• Prior malignancy allowed provided patient was curatively treated and has been disease-free for an appropriate time period for the specific cancer
• No known HIV positivity
• No active infection
• No major depression or suicidal ideation
• No other condition that would preclude study compliance
• No other uncontrolled medical condition
• PRIOR CONCURRENT THERAPY:
• Biologic therapy
• Not specified
• Chemotherapy
• No prior chemotherapy for any malignancy
• Endocrine therapy
• At least 2 weeks since prior and no concurrent finasteride (Prosear® or Propecia®) or other androgen suppressor
• No concurrent corticosteroids
• Radiotherapy
• Not specified
• Surgery
• Not specified
• Other
• At least 2 weeks since prior phenytoin or phenobarbital
• At least 2 weeks since prior ketoconazole
• No concurrent administration of any of the following:
• * Magnesium-containing antacids
• * Thiazide diuretics
• * Calcium supplements
• * Digoxin
• * Herbal supplements
• * Pharmacological doses of cholecalciferol (vitamin D) or its derivatives