DISEASE CHARACTERISTICS:

• Histologically confirmed adenocarcinoma of the prostate
• No small cell, neuroendocrine, or transitional cell carcinomas

• At least 1 bone metastasis by bone scan, MRI, CT scan, or plain radiographs

  • Indeterminate lesions should be confirmed by a second imaging method
  • At least 1 bone metastasis with no prior irradiation

• Concurrent androgen deprivation therapy required, defined as any of the following:

  • Bilateral orchiectomy
  • Gonadotropin-releasing hormone (GnRH) agonist with or without an antiandrogen

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• ECOG 0-2

Life expectancy

• Not specified

Hematopoietic

• Not specified

Hepatic

• Not specified

Renal

• Creatinine clearance ≥ 30 mL/min
• Corrected calcium ≥ 8.0 mg/dL and < 11.6 mg/dL

Other

• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Concurrent standard biologic response modifiers allowed during open-label therapy only

Chemotherapy

• Concurrent standard cytotoxic chemotherapy allowed during open-label therapy only

Endocrine therapy

• See Disease Characteristics
• Prior neoadjuvant and/or adjuvant hormonal therapy allowed provided duration of therapy was no more than 6 months AND therapy was discontinued more than 6 months before study entry

• No more than 6 months since initiation of any of the following hormonal therapies:

  • Orchiectomy
  • GnRH agonist (e.g., leuprolide, goserelin, or triptorelin)
  • Estrogen therapy
  • Antiandrogens (e.g., bicalutamide, flutamide, or nilutamide)
  • Any other therapy known to lower testosterone levels or inhibit testosterone effect
• No intermittent androgen deprivation therapy except for patients concurrently enrolled on SWOG-9346
• Concurrent palliative corticosteroids allowed during open-label therapy only
• Concurrent standard hormonal agents allowed during open-label therapy only

Radiotherapy

• See Disease Characteristics
• No prior radiopharmaceuticals
• At least 4 weeks since prior radiotherapy
• Concurrent standard radiotherapy to extraskeletal and/or skeletal tumor sites allowed during open-label therapy only

Surgery

• See Disease Characteristics

Other

• No prior bisphosphonates
• No other concurrent agents expected to alter osteoclast activity (e.g., calcitonin, mithramycin, gallium nitrate, or any other bisphosphonate)
• Concurrent daily supplemental elemental calcium (500 mg) and a multivitamin containing cholecalciferol (Vitamin D) (400 IU) OR a combination tablet containing both recommended
• Concurrent standard marketed antineoplastic therapies allowed during open-label therapy only