Calcitriol and Zoledronate in Treating Patients With Progressive Prostate Cancer

DISEASE CHARACTERISTICS:

* Histologically confirmed prior localized adenocarcinoma of the prostate that has undergone definitive radiation or surgery and demonstrates progression biochemically with all of the following:

  * Baseline PSA at least 4 ng/mL
  * At least a 50% increase in PSA over at least 3 determinations taken at more than 2 week intervals
  * No radiographically evident disease
  * Neoadjuvant hormonal therapy prior to radical prostatectomy or radiotherapy allowed
  * Treatment in an intermittent approach allowed if off therapy for at least 12 weeks OR
* Histologically confirmed androgen-independent adenocarcinoma of the prostate with all of the following:

  * Progression on primary hormonal treatment (e.g., orchiectomy, estrogen therapy, gonadotropin-releasing hormone analog with or without an antiandrogen) with either new osseous lesions in bone, a greater than 25% increase in bidimensionally measurable tumor mass, or rising PSA values (rising PSA on any 3 determinations taken at at least weekly intervals, to greater than 50% above baseline PSA) despite castrate levels of testosterone (no greater than 30 ng/mL)
  * If receiving antiandrogen as part of primary hormonal therapy, must meet criteria above for progression after discontinuation of antiandrogen
  * No change in hormonal therapy (including prednisone or dexamethasone) within the past 2 weeks
  * If no prior surgical orchiectomy, must continue on medical therapies to maintain castrate levels of testosterone
  * Prior chemotherapy, palliative radiotherapy, or radioisotope treatment allowed

PATIENT CHARACTERISTICS:

Age:

* 18 and over

Performance status:

* Karnofsky 70-100%

Life expectancy:

* At least 3 months

Hematopoietic:

* WBC at least 3,500/mm\^3
* Platelet count at least 100,000/mm\^3

Hepatic:

* Bilirubin less than 2.0 mg/dL OR
* SGOT less than 3 times upper limit of normal

Renal:

* Creatinine less than 1.5 mg/dL OR
* Creatinine clearance at least 60 mL/min
* No history of nephrolithiasis
* Must have 2 functioning kidneys

Cardiovascular:

* No New York Heart Association class III or IV heart disease

Pulmonary:

* No severe debilitating pulmonary disease

Metabolic:

* No pre-existing endocrine or metabolic disorders that impact calcium regulatory axis including hypercalcemia (ionized serum calcium greater than 5.3 mg/dL or total calcium greater than 10.5 mg/dL) or hypercalciuria (greater than 300 mg urinary calcium/24 hours)

Other:

* No active secondary malignancy except nonmelanoma skin cancer
* Must maintain low calcium diet (less than 800 mg calcium daily)
* No uncontrolled serious active infection
* No history of malabsorption disorders
* No history of inflammatory bowel disease

PRIOR CONCURRENT THERAPY:

Biologic therapy:

* Not specified

Chemotherapy:

* See Disease Characteristics
* At least 4 weeks since prior chemotherapy and recovered
* No concurrent chemotherapy

Endocrine therapy:

* See Disease Characteristics
* Recovered from prior endocrine therapy

Radiotherapy:

* See Disease Characteristics
* At least 4 weeks since prior radiotherapy and recovered
* No concurrent radiotherapy to sole measurable lesion

Surgery:

* See Disease Characteristics
* Recovered from prior surgery
* No concurrent surgery to sole measurable lesion

Other:

* No other concurrent cholecalciferol