Low Accrual

RATIONALE: Bortezomib may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Androgens can cause the growth of prostate cancer cells. Drugs, such as goserelin, leuprolide, flutamide, or bicalutamide, may stop the adrenal glands from making androgens. Giving bortezomib with hormone therapy may kill more tumor cells.

PURPOSE: This phase II trial is studying how well giving bortezomib with or without hormone therapy works 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

from start of treatment until end of study visit, about 6 months