RATIONALE: Studying samples of blood and tissue from patients with prostate cancer after receiving implant radiation therapy and luteinizing hormone-releasing hormone agonist may help doctors identify biomarkers related to cancer and help doctors predict how patients will respond to treatment.

PURPOSE: This laboratory study is looking at PSA levels and biopsy samples after undergoing implant radiation therapy and luteinizing hormone-releasing hormone agonist therapy in patients with stage I or stage II prostate cancer.

OBJECTIVES:

• To analyze biopsy results at 36 months after permanent iodine I 125 implantation therapy and luteinizing hormone-releasing hormone (LHRH) agonist therapy for patients with untreated intermediate-risk prostate cancer.

OUTLINE: Patients received luteinizing hormone releasing-hormone (LHRH) agonist therapy and permanent iodine I 125 implantation on protocol JUSMH-BRI-GU05-01.

Patients undergo blood sample collection and tissue biopsy for biomarker/laboratory analysis at 36 months after receiving brachytherapy and releasing-hormone agonist therapy. PSA levels and biopsy results are compared.

DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed prostate cancer

  • Previously untreated disease prior to participation on protocol JUSMH-BRI-GU05-01

• Intermediate-risk disease as defined by the following:

  • Clinical stage < T2c
  • Prostate-specific antigen (PSA) ≤ 20 ng/mL
  • Gleason score < 8

• Previously enrolled on protocol JUSMH-BRI-GU05-01

PATIENT CHARACTERISTICS:

• ECOG performance status 0-1
• Life expectancy ≥ 3 months
• WBC ≥ 2,000/μL
• Hemoglobin ≥ 10.0 g/dL
• Platelet count ≥ 100,000/μL
• Serum creatine level ≤ 2.0 mg/dL
• ALT and AST ≤ 100 IU/L
• No other cancer requiring treatment
• No poorly controlled hypertension (i.e., diastolic blood pressure ≥ 120 mm Hg)
• No severe psychiatric disorders, including schizophrenia or dementia
• No poorly controlled diabetes
• Considered appropriate for study participation, as determined by the Principal Investigator or Clinical Investigator

PRIOR CONCURRENT THERAPY:

• No prior drugs for benign prostatic hyperplasia (other than antiandrogen therapy)
• No prior surgery for prostate cancer
• No concurrent steroid drugs (except for ointment)
• No other concurrent antiandrogen therapy

Previously enrolled on protocol JUSMH-BRI-GU05-01 and 36 month after treatement of brachytherapy.