Zolendronate for the Prevention of Bone Loss in Men w/ Prostate CA on Long-Term Androgen Deprivation

DISEASE CHARACTERISTICS: * Histologically confirmed prostate cancer * Stage III or IV disease * Received at least 3 months of prior androgen deprivation therapy (no maximum amount/time) by either surgical or medical castration * Medical castration may be by intermittent or continuous androgen suppression via single- or combined-drug androgen blockade * Continued concurrent androgen deprivation therapy required throughout study participation * No bone metastases by baseline bone scan PATIENT CHARACTERISTICS: Age * 18 and over Performance status * ECOG 0-2 Life expectancy * At least 1 year Hematopoietic * Not specified Hepatic * Bilirubin less than 3 times upper limit of normal (ULN) * AST and ALT less than 3 times ULN * No chronic liver disease Renal * Creatinine no greater than 2.0 mg/dL Other * Fertile patients must use effective contraception * No Paget's disease * No Cushing's disease * No hyperthyroidism * No hyperprolactinemia PRIOR CONCURRENT THERAPY: Biologic therapy * Not specified Chemotherapy * Prior chemotherapy for prostate cancer allowed Endocrine therapy * See Disease Characteristics * More than 12 months since prior suppressive doses of thyroxine or calcitonin * More than 6 months since prior corticosteroids * Concurrent corticosteroids allowed (after enrollment on study) Radiotherapy * Prior radiotherapy for prostate cancer allowed Surgery * See Disease Characteristics Other * More than 12 months since prior bisphosphonate th…