Bortezomib With or Without Hormone Therapy in Treating Patients With Relapsed Prostate Cancer

DISEASE CHARACTERISTICS: Histologically confirmed adenocarcinoma of the prostate Relapsed disease after definitive local therapy, as documented only by a rise in prostate-specific antigen (PSA) Experienced PSA relapse after definitive local therapy Rising PSA (≥ 1.0 ng/mL after nadir < 1.0 ng/mL) PSA increase of ≥ 0.3 ng/mL (increase occurred between 2 separate measurements taken ≥ 4 weeks apart) The first of these two PSA values must rise above a previously recorded post-therapy nadir value Ineligible for curative therapy No clinical evidence of local recurrence (i.e., palpable induration or mass in the prostatic fossa) other than PSA elevation No evidence of palpable disease in the prostatic bed No metastatic disease (M0) No non-nodal (> N1) metastasis No evidence of osseous metastasis on bone scan within the past 28 days PATIENT CHARACTERISTICS: Age Over 18 Performance status ECOG 0-1 Life expectancy At least 1 year Hematopoietic Platelet count ≥ 30,000/mm^3 Absolute neutrophil count ≥ 1,000/mm^3 Hepatic No known hepatitis B or C positivity Renal Creatinine clearance ≥ 30 mL/min Immunologic No known human T-cell lymphotropic virus positivity No hypersensitivity to bortezomib, boron, or mannitol No known HIV 1 or 2 positivity No active, ongoing bacterial, viral, or fungal infection Other Fertile patients must use effective contraception No peripheral neuropathy ≥ grade 2 No other disease, condition, or social or geographic constraint that would preclude study participation No other malignancy within the past 5 years except basal cell or squamous cell skin cancer PRIOR CONCURRENT THERAPY: Biologic therapy Not specified Chemotherapy No concurrent chemotherapy Endocrine therapy See Disease Characteristics At least 6 months since prior hormonal therapy combined with radiation therapy as definitive therapy Neoadjuvant hormonal therapy prior to definitive therapy (e.g., surgery, radiation therapy, brachytherapy, or cryoablation) allowed No other concurrent hormonal therapy Radiotherapy See Disease Characteristics More than 12 months since prior radioactive seed therapy No concurrent radiotherapy Surgery See Disease Characteristics More than 4 weeks since prior surgery No concurrent surgery Other No concurrent second-line herbal preparations, including PC-SPES No other concurrent investigational agents