Comparison of Two Radiation Therapy Regimens in Treating Patients With Stage II or Stage III Prostate Cancer

OBJECTIVES:

• Compare the efficacy of conventional intensity-modulated radiotherapy (IMRT) vs hypofractionated IMRT, in terms of freedom from biochemical failure in men with intermediate- to high-risk prostate cancer.
• Compare the local control, freedom from distant metastasis, and overall survival of patients treated with these regimens.
• Determine local failure, using biopsy of the prostate, when objective tests (prostate-specific antigen, ultrasound, and digital rectal exam) suggest relapse in these patients.
• Compare the extent of disease eradication using biopsy of the prostate at 2 years after therapy in these patients.
• Compare the quality of life of patients treated with these regimens.
• Determine the impact of these regimens on patient preferences and utilities.

OUTLINE: This is a randomized study. Patients are stratified according to pretreatment prostate-specific antigen (no greater than 10 ng/mL vs greater than 10 to 20 ng/mL vs greater than 20 ng/mL), Gleason score (5-7 vs 8-10), and risk status (high risk vs intermediate risk). Patients are randomized to 1 of 2 treatment arms.

• Arm I: Patients undergo conventional intensity-modulated radiotherapy (IMRT) 5 days a week for 7.5 weeks in the absence of disease progression or unacceptable toxicity.
• Arm II: Patients undergo hypofractionated IMRT 5 days a week for 5 weeks in the absence of disease progression or unacceptable toxicity.

Patients with high-risk disease also undergo androgen deprivation therapy for 2 years.

Quality of life is assessed at baseline, every 6 months for 1 year, and then annually for 4 years.

Patients are followed at 3 months, every 6 months for 2 years, and then annually thereafter.

PROJECTED ACCRUAL: A total of 300 patients (150 per treatment arm) will be accrued for this study within 3 years.

DISEASE CHARACTERISTICS:

• Histologically confirmed adenocarcinoma of the prostate

• Clinical stage T1b-T3c disease
• No clinical or radiographic evidence of metastasis
• Prostate-specific antigen (PSA) less than 80 ng/mL
• Gleason score at least 5
• One of the following criteria must be met:

• PSA greater than 10 ng/mL
• Gleason score greater than 6
• T2b or greater palpable disease
• Three or more biopsy cores involved with a Gleason score of at least 5

PATIENT CHARACTERISTICS:

Age

• Not specified

Performance status

• Zubrod 0-1

Life expectancy

• Not specified

Hematopoietic

• Not specified

Hepatic

• Not specified

Renal

• Not specified

Other

• No other medical condition that would preclude study participation
• No other active malignancy within the past 5 years except nonmetastatic skin cancer or early stage chronic lymphocytic leukemia (well-differentiated small cell lymphocytic leukemia)
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Not specified

Chemotherapy

• Not specified

Endocrine therapy

• No more than 4 months of prior androgen deprivation therapy
• Neoadjuvant and adjuvant androgen deprivation therapy is allowed for high-risk disease only

Radiotherapy

• No prior pelvic radiotherapy

Surgery

• No prior or planned radical prostate surgery