• Treatment-specific symptoms as measured on the four-item Medical Outcomes Study Short Form-36 (SF-36) and Vitality scale [ Designated as safety issue: No ]
  
• Physical functioning as measured by the SF-36 [ Designated as safety issue: No ]
  
• Emotional functioning as measured by the SF-36 Mental Health Inventory [ Designated as safety issue: No ]
  

• Symptoms as assessed by the Symptom Distress Scale [ Designated as safety issue: No ]
  
• Role functioning as assessed by the Role Functioning Scale SF-20 [ Designated as safety issue: No ]
  
• Social functioning as assessed by the General Health Survey SF-20 [ Designated as safety issue: No ]
  
• Global quality of life (QOL) and health-related QOL [ Designated as safety issue: No ]
  
• Comorbidity, social support, and demographic variables [ Designated as safety issue: No ]
  

OBJECTIVES:

Primary

• Compare the survival of patients with metastatic stage IV prostate cancer responsive to combined androgen-deprivation therapy (CAD) treated with intermittent vs continuous CAD.
• Compare the effects of these treatment regimens on impotence, libido, and vitality/fatigue as well as the physical and emotional well-being of these patients.

Secondary

• Compare general symptoms, role functioning, global perception of quality of life, and social functioning of patients treated with these regimens.
• Assess prostate-specific antigen (PSA) levels after continuous CAD administered before randomization and evaluate PSA changes throughout randomized treatment of these patients.

OUTLINE: This is a randomized, multicenter study. Patients are stratified according to SWOG performance status (0-1 vs 2), severity of disease (minimal vs extensive), and prior hormonal therapy (neoadjuvant hormonal therapy vs finasteride vs neither).

• Induction therapy: Patients receive combined androgen-deprivation (CAD) therapy comprising goserelin subcutaneously once a month and oral bicalutamide once daily for 8 courses (7 months).

• Consolidation therapy: Patients are randomized to 1 of 2 consolidation regimens.

  • Arm I (continuous CAD therapy): Patients continue CAD therapy as in induction therapy. Treatment continues in the absence of disease progression.
  • Arm II (intermittent CAD therapy): Patients undergo observation in the absence of rising prostate-specific antigen (PSA) or clinical symptoms of progressive disease. Patients with rising PSA or progressive disease begin CAD therapy as in induction therapy. Patients whose PSA normalizes after 8 courses return to observation. Patients whose PSA does not normalize after 8 courses continue CAD therapy.

Quality of life is assessed before induction therapy, at 3 months (before consolidation therapy), and then at 9 and 15 months.

Patients are followed every 6 months.

PROJECTED ACCRUAL: Approximately 1,500 patients will be accrued for this study.

DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed adenocarcinoma of the prostate

  • Metastatic stage IV (stage D2)

    • Any number of bone metastases by bone scan allowed
    • Unequivocal visceral organ metastases (liver, brain, or lung) allowed
  • No suspected second primary tumors unless metastases are histologically confirmed, including special stains (e.g., prostate specific antigen [PSA] and prostatic alkaline phosphatase [PAP])

• For entry into late induction therapy:

  • No more than 1 month from the beginning of antiandrogen therapy to the beginning of luteinizing hormone-releasing hormone (LHRH) agonist therapy
  • No more than 6 months since initiation of current combined androgen-deprivation therapy (LHRH agonist and antiandrogen)
  • The effectiveness of the current depot LHRH agonist would not extend beyond 8 months after initiation of combined androgen therapy
• PSA at least 5 ng/mL
• No acute spinal cord compression

PATIENT CHARACTERISTICS:

Age:

• Adult

Performance status:

• SWOG 0-2

Hematopoietic:

• Not specified

Hepatic:

• Not specified

Renal:

• Not specified

Other:

• Recovered from any major infection
• No active medical illness that would preclude study or limit survival

• No other malignancy within the past 5 years except:

  • Adequately treated basal cell or squamous cell skin cancer
  • Adequately treated carcinoma in situ of the bladder
  • Adequately treated other superficial cancer

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• No concurrent biological response modifier therapy

Chemotherapy:

• No concurrent chemotherapy

Endocrine therapy:

• See Disease Characteristics

• More than 1 year since any prior neoadjuvant or adjuvant hormonal therapy for a duration of no more than 4 months

  • Single or combination therapy allowed
• More than 1 year since prior finasteride for prostate cancer for a duration of no more than 9 months (less than 6 months for benign prostatic hypertrophy)
• Prior or concurrent megestrol for hot flashes allowed
• No other concurrent hormonal therapy

Radiotherapy:

• No concurrent radiotherapy other than palliation of painful bone metastases

Surgery:

• No prior bilateral orchiectomy
• Recovered from any prior major surgery