Androgen Blockade Therapy With or Without Zoledronic Acid in Treating Patients With Prostate Cancer and Bone Metastases

Inclusion Criteria: * Patients with definitive diagnosis of prostatic cancer by histopathological diagnosis or cytology * Androgen blockade therapy-, systemic chemotherapy-, bisphosphonates-naïve prostatic cancer patients * Patients who are sensitive to androgen blockade therapy * Patients with bone metastasis on bone scan (EOD ≥ 1) * Patients who have Eastern Cooperative Oncology Group performance status (ECOG: 0-2) * Patients who have prostate-specific antigen performance status (PSA ≧30 ng/mL) * Patients who demonstrate appropriate bone marrow, hepatic and renal functions in laboratory tests within four weeks before the registration. * Leukocyte count ≥ 3,000/μL * Hemoglobin ≥ 9.0 g/dL * Platelet count ≥ 7.5 × 10\^4/μL * Serum creatine level ≤ 3.0 mg/dL * 8.5 mg/dL ≤ corrected serum level of calcium ≤ 11.5 mg/dL * Total bilirubin ≤ 1.8 mg/dL * Aspartate aminotransferase (AST) Levels ≤ 90 IU/L * Alanine aminotransferase (ALT) Levels ≤ 100 IU/L * Patients who agreed to participate in this clinical study in writing after receiving sufficient explanation Exclusion criteria: * Patients with poorly-controlled dental caries * Patients with double cancer that requires treatment * Patients who are using following steroid drugs (except for topical ointment) * Patients with poorly-controlled hypertension or cardiovascular disease * Patients with active infectious diseases or HIV or hepatitis virus infections * Other patients whose participation in the present study is considered inappropriate by a Principal Investigator or Clinical Investigator PRIOR CONCURRENT THERAPY: * No prior androgen-blockade therapy * No prior or other concurrent anticancer therapy * No prior or concurrent immunologic adjuvant therapy * No prior or concurrent steroid drugs (except ointment) * No other prior or concurrent bisphosphonates (excluding zoledronic acid) * No prior systemic chemotherapy