RATIONALE: Radiation therapy uses high-energy x-rays to damage tumor cells. Giving radiation therapy in different ways may cause less damage to normal tissue and may improve quality of life and help patients live more comfortably. Androgens can stimulate the growth of prostate cancer cells. Drugs such as goserelin and bicalutamide may fight cancer by stopping the production of androgens. It is not yet known whether radiation therapy is more effective with or without goserelin and bicalutamide in treating prostate cancer.

PURPOSE: Randomized phase III trial to compare the effectiveness of high-dose radiation therapy with or without bicalutamide and goserelin in treating patients who have prostate cancer.

OBJECTIVES:

• Compare the quality of life of patients with high-grade intermediate-risk or unfavorable-risk adenocarcinoma of the prostate when treated with high-dose intensity-modulated radiotherapy alone versus with androgen deprivation comprising bicalutamide and goserelin.
• Compare the prostate-specific antigen relapse-free, distant metastases-free, and overall survival of patients treated with these regimens.
• Compare the toxicity of these regimens in these patients.
• Compare the local control in patients treated with these regimens, based on post-treatment sextant biopsies performed 4 years after study completion.

OUTLINE: This is a randomized study. Patients are stratified according to prostate-specific antigen level, Gleason score, and clinical stage. Patients are randomized to 1 of 2 treatment arms.

• Arm I: Patients undergo high-dose intensity-modulated radiotherapy (IMRT) 4-5 times per week for 10 weeks (a total of 48 treatments).
• Arm II: Patients receive oral bicalutamide once daily for 18.5 weeks. Three to seven days after the initiation of bicalutamide, patients also receive goserelin subcutaneously monthly for 2 years. Beginning after 10 weeks of hormonal therapy, patients undergo concurrent high-dose IMRT 4-5 times per week for 8.5 weeks (a total of 42 treatments). Patients discontinue bicalutamide on or near the end of radiotherapy.

In both arms, treatment continues in the absence of disease progression or unacceptable toxicity.

Quality of life is assessed at baseline, every 3 months for 1.5 years after the completion of radiotherapy, then 6 months later, and then annually for 2 years.

Patients are followed every 6-8 months for 4 years and then annually for 2 years.

PROJECTED ACCRUAL: A total of 400 patients (200 per treatment arm) will be accrued for this study within 4-5 years.

DISEASE CHARACTERISTICS:

• Histologically confirmed adenocarcinoma of the prostate

• Unfavorable-risk disease, including at least 2 of the following characteristics:

  • Prostate-specific antigen level greater than 10 ng/mL
  • Gleason score greater than 7
  • Stage T4

• Intermediate-risk disease with a Gleason score of at least 8 allowed

• Lymph nodes clinically negative by imaging studies or histologically negative by node sampling or lymph node dissection

• Prostate size less than 75 grams

• No distant metastases by bone scan, CT scan, or MRI

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• Karnofsky 80-100%

Life expectancy

• Not specified

Hematopoietic

• Not specified

Hepatic

• Bilirubin no greater than 1.5 times upper limit of normal (ULN)
• SGOT and SGPT no greater than 1.5 times ULN

Renal

• Not specified

Other

• No documented history of inflammatory bowel disease
• No bilateral hip replacements
• No other invasive cancer except localized basal cell or squamous cell skin cancer unless disease free for at least 5 years
• No major medical or psychiatric illness that would preclude study completion, compliance, or follow-up

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Not specified

Chemotherapy

• No prior chemotherapy for prostate cancer

Endocrine therapy

• No prior androgen-deprivation therapy

Radiotherapy

• No prior pelvic radiotherapy
• No prior prostate brachytherapy

Surgery

• No prior bilateral orchiectomy
• No prior radical prostatectomy
• No prior cryotherapy for prostate cancer