Inclusion Criteria

DISEASE CHARACTERISTICS:

- Pathologically (histologically or cytologically) proven diagnosis of prostatic
adenocarcinoma within 180 days of registration at moderate- to high-risk for
recurrence as determined by one of the following combinations:

- Gleason score 7-10 + T1c-T2b (palpation) + prostate-specific antigen (PSA) < 50
ng/mL (includes intermediate- and high-risk patients)

- Gleason score 6 + T2c-T4 (palpation) or > 50% (positive) biopsies + PSA < 50
ng/mL

- Gleason score 6 + T1c-T2b (palpation) + PSA > 20 ng/mL

- History and/or physical examination (to include at a minimum digital rectal
examination of the prostate and examination of the skeletal system and abdomen)
within 90 days prior to registration

- Clinically negative lymph nodes as established by imaging (pelvic and/or abdominal CT
or MR), (but not by nodal sampling, or dissection) within 90 days prior to
registration

- Patients with lymph nodes equivocal or questionable by imaging are eligible if
the nodes are ≤ 1.5 cm

- Patients status post a negative lymph node dissection are not eligible

- No evidence of bone metastases (M0) on bone scan within 120 days prior to
registration

- Equivocal bone scan findings are allowed if plain films (or CT or MRI) are
negative for metastasis

- Baseline serum PSA value performed with an FDA-approved assay (e.g., Abbott,
Hybritech) within 12 weeks (90 days) prior to registration

- Study entry PSA should not be obtained during the following time frames:

- Ten-day period following prostate biopsy

- Following initiation of hormonal therapy

- Within 30 days after discontinuation of finasteride

- Within 90 days after discontinuation of dutasteride

PATIENT CHARACTERISTICS:

- Zubrod performance status 0-1

- ANC ≥ 1,500/mm³

- Platelet count ≥ 100,000/mm³

- Hemoglobin (Hgb) ≥ 8.0 g/dL (transfusion or other intervention to achieve Hgb ≥ 8.0
g/dL is acceptable)

- No prior invasive (except non-melanoma skin cancer) malignancy unless disease-free
for a minimum of 3 years (1,095 days) and not in the pelvis

- E.g., carcinoma in situ of the oral cavity is permissible; however, patients
with prior history of bladder cancer are not allowed

- No prior hematological (e.g., leukemia, lymphoma, or myeloma) malignancy

- No severe, active co-morbidity, defined as any of the following:

- Unstable angina and/or congestive heart failure requiring hospitalization within
the last 6 months

- Transmural myocardial infarction within the last 6 months

- Acute bacterial or fungal infection requiring intravenous antibiotics at the
time of registration

- Chronic obstructive pulmonary disease exacerbation or other respiratory illness
requiring hospitalization or precluding study therapy at the time of
registration

- Hepatic insufficiency resulting in clinical jaundice and/or coagulation defects
or severe liver dysfunction

- Acquired immune deficiency syndrome (AIDS) based upon current CDC definition

- Protocol-specific requirements may also exclude immuno-compromised patients

- HIV testing is not required for entry into this protocol

- No patients who are sexually active and not willing/able to use medically acceptable
forms of contraception

- No prior allergic reaction to the hormones involved in this protocol

PRIOR CONCURRENT THERAPY:

- See Disease Characteristics

- No prior radical surgery (prostatectomy) or cryosurgery for prostate cancer

- No prior pelvic irradiation, prostate brachytherapy, or bilateral orchiectomy

- No prior hormonal therapy, such as luteinizing hormone-releasing hormone (LHRH)
agonists (e.g., leuprolide, goserelin, buserelin, triptorelin) or LHRH antagonist
(e.g., degarelix), anti-androgens (e.g., flutamide, bicalutamide, cyproterone
acetate), estrogens (e.g., diethylstilbestrol [DES]), or surgical castration
(orchiectomy)

- No prior pharmacologic androgen ablation for prostate cancer unless the onset of
androgen ablation is ≤ 45 days prior to the date of registration

- No finasteride within 30 days prior to registration

- No dutasteride or dutasteride/tamsulosin (Jalyn) within 90 days prior to registration

- No prior or concurrent cytotoxic chemotherapy for prostate cancer

- Prior chemotherapy for a different cancer is allowable

- No prior radiotherapy, including brachytherapy, to the region of the study cancer
that would result in overlap of radiation therapy fields