Androgen Suppression Plus Radiation Therapy in Treating Patients With Prostate Cancer

OBJECTIVES:

• Determine the feasibility of androgen-suppression therapy combined with external-beam radiotherapy and boost brachytherapy (EBRT+BT) in patients with intermediate-risk localized prostate cancer.
• Determine the safety of EBRT+BT in these patients.
• Determine, in a preliminary manner, the efficacy of EBRT+BT in terms of rate of local recurrence at 5 years, time to prostate-specific antigen failure, and time to first rectal/bladder injury, in these patients.

OUTLINE: Patients receive either leuprolide intramuscularly or goserelin subcutaneously once every 12 weeks for a total of 24 weeks. Patients also receive either oral flutamide three times daily or oral bicalutamide once daily for 4 weeks.

Within 4 weeks after initiation of androgen-suppression therapy, patients undergo external-beam radiotherapy (EBRT) once daily, 5 days a week, for 5 weeks. At 2-4 weeks after completion of EBRT, patients undergo transrectal ultrasound-guided boost brachytherapy with implanted iodine I 125 or palladium Pd 103 seeds.

Patients are followed every 3 months for 2 years and then every 6 months for 4 years.

PROJECTED ACCRUAL: A total of 60 patients will be accrued for this study.

DISEASE CHARACTERISTICS:

• Histologically confirmed adenocarcinoma of the prostate

• Must have one of the following prognostic factors:

• Stage T1-2, N0; prostate-specific antigen (PSA) ≤ 10 ng/mL; and Gleason score > 6
• Stage T1-2, N0; PSA > 10 ng/mL and < 20 ng/mL; and Gleason score ≤ 6
• Stage T3a, N0; PSA ≤ 10 ng/mL; and Gleason score ≤ 6
• Prostate volume < 60 cc by transrectal ultrasound
• No distant or nodal metastases

• No metastatic disease by bone scan, CT scan, or MRI

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• ECOG 0-2

Life expectancy:

• Not specified

Hematopoietic:

• Absolute neutrophil count ≥ 1,500/mm^3
• Platelet count ≥ 100,000/mm^3

Hepatic:

• Bilirubin ≤ 1.5 times upper limit of normal

Renal:

• Not specified

Other:

• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• No prior immunotherapy for prostate cancer

Chemotherapy:

• No prior chemotherapy for prostate cancer

Endocrine therapy:

• Prior androgen-suppression therapy for up to 4 weeks duration allowed if initiated within 4 weeks of study radiotherapy
• No other prior hormonal therapy

Radiotherapy:

• No prior radiotherapy for prostate cancer

Surgery:

• No prior surgery for prostate cancer
• No prior transurethral resection of the prostate

Other:

• No prior alternative therapy (e.g., PC-SPES) for prostate cancer