Radiation Therapy With or Without Androgen-Deprivation Therapy in Treating Patients With Prostate Cancer

OBJECTIVES:

Primary

- Demonstrate an overall survival (OS) advantage in patients with intermediate-risk
prostate cancer treated with dose-escalated radiotherapy (RT) with versus without
short-term androgen-deprivation therapy (ADT).

Secondary

- Determine whether the addition of ADT to dose-escalated RT versus RT alone improves
clinical failures, biochemical failure by the "nadir +2", freedom from failure, rate of
salvage ADT, and prostate cancer-specific mortality in these patients.

- Estimate the magnitude of benefit of ADT with respect to OS in patients treated with
different RT modalities (i.e., external-beam radiation therapy alone vs low-dose rate
brachytherapy boost vs high-dose rate brachytherapy boost).

- Compare acute and late treatment adverse events of these regimens and correlate these
events with the presence or absence of pre-existing comorbidity as documented by the
Adult Comorbidity Evaluation 27 assessment.

OUTLINE: This is a multicenter, dose-escalation study of radiotherapy. Patients are
stratified according to number of risk factors (1 vs 2-3), comorbidity (ACE-27 grade ≥ 2 vs <
2), and radiotherapy (RT) modality (dose-escalated external-beam RT [EBRT] vs EBRT and
low-dose rate brachytherapy boost vs EBRT and high-dose rate brachytherapy boost). Patients
are randomized to 1 of 2 treatment arms.

- Arm I: Patients undergo EBRT* once daily on days 1-5 for about 9 weeks (44 treatments).
Some patients instead receive EBRT with high-dose rate or low-dose rate brachytherapy
implant on days 1-5 for about 5 weeks (25 treatments). NOTE: *Type of RT is at
discretion of treating physician and may include either 3D-conformal RT or
intensity-modulated RT.

- Arm II: Patients receive androgen-deprivation therapy comprising luteinizing-hormone
releasing-hormone (LHRH) agonist (leuprolide, goserelin, buserelin, or triptorelin)
subcutaneously or as an injection every 1 to 3 months AND an oral antiandrogen therapy
(flutamide 3 times daily or bicalutamide once daily) for 6 months. Beginning 8 weeks
after the first LHRH injection, patients undergo radiotherapy as in arm I.

After completion of study therapy, patients are followed up periodically.

DISEASE CHARACTERISTICS:

- Histologically confirmed adenocarcinoma of the prostate diagnosed within the past 180
days and at intermediate-risk for recurrence by meeting 1 or more of the following
criteria:

- Gleason score = 7

- Prostate Specific Antigen (PSA) > 10 and ≤ 20 ng/mL

- Baseline serum PSA value performed within 60 days with an FDA-approved assay
(e.g., Abbott, Hybritech)

- Baseline PSA must not be obtained during any of the following time
frames:10-day period after prostate biopsy, after initiation of
androgen-deprivation therapy, or within the past 30 days after
discontinuation of finasteride (90 days for dutasteride)

- Clinical stage T2b or T2c disease

- Patients previously diagnosed with low-risk (Gleason score < 6, clinical stage <
T2a, and PSA < 10 ng/mL) prostate cancer undergoing active surveillance who are
re-biopsied and found to have intermediate-risk disease according to the protocol
criteria are eligible for enrollment within 6 months of the repeat biopsy
procedure

- Patients with Gleason Score ≥ 8, PSA > 20 ng/mL, OR clinical stage ≥ T3 are ineligible
for this trial

- If findings of extracapsular extension or seminal vesicle invasion are noted on
prostate MRI, this study, if used, will not render patients ineligible for
accrual to this protocol

- Primary tumor staging for eligibility purposes is to be based on palpable or core
biopsy evidence only with respect to extracapsular extension or seminal vesicle
involvement

- No patients with all 3 intermediate-risk factors who also have ≥ 50% of the number of
their biopsy cores positive for cancer

- The percentage of biopsy cores involved will only be considered with respect to
eligibility for those patients with all 3 of the above risk factors (i.e.,
patients with one or two of the above risk factors are eligible irrespective of
the percentage of biopsy cores involved)

- Clinically negative lymph nodes as established by imaging (pelvic and/or abdominal CT
scan or MRI), nodal sampling, or dissection within the past 60 days (required for
patients with 2-3 risk factors)

- Abdominal imaging not required for a single intermediate-risk factor (these
studies may be obtained at the discretion of the treating physician)

- Lymph nodes that are equivocal or questionable by imaging allowed without biopsy
if nodes ≤ 1.5 cm

- Any node > 1.5 cm on imaging requires a negative biopsy

- No evidence of bone metastases on bone scan within the past 60 days

- Bone scan not required for patients with a single intermediate-risk factor (scan
may be obtained at the discretion of the treating physician)

- Equivocal bone scan findings allowed if plain film x-rays negative for metastasis

PATIENT CHARACTERISTICS:

- Zubrod performance status 0-1

- Absolute neutrophil count (ANC) ≥ 1,800/mm^3*

- Platelet count ≥ 100,000/mm^3*

- Hemoglobin ≥ 8.0 g/dL (transfusion or other intervention to achieve level allowed)*

- NOTE: *For patients undergoing brachytherapy only.

- Fertile patients must use effective contraception during and for the 3 months after
cessation of protocol treatment

- No invasive malignancy or hematological malignancy (e.g., leukemia, lymphoma, myeloma)
within the past 5 years except adequately treated non-melanomatous skin cancer

- Prior diagnoses of carcinoma in situ allowed

- No severe or active co-morbidity with any of the following:

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

- Transmural myocardial infarction within the past 6 months

- Acute bacterial or fungal infection requiring intravenous antibiotics

- Chronic obstructive pulmonary disease exacerbation or other respiratory illness
requiring hospitalization or precluding study therapy, within the past 30 days

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

- Laboratory tests for liver function and coagulation parameters not required
for entry into this protocol

- AIDS based upon current Centers for Disease Control (CDC) definition

- HIV testing not required for entry into this protocol

- HIV-seropositive patients who do not meet criteria for diagnosis of AIDS
allowed

PRIOR CONCURRENT THERAPY:

- See Disease Characteristics

- No prior radical surgery (prostatectomy), high-intensity focused ultrasound, or
cryosurgery for prostate cancer

- No prior hormonal therapy, such as LHRH agonists (e.g., goserelin, leuprolide),
antiandrogens (e.g., flutamide, bicalutamide), estrogens (e.g., DES), or bilateral
orchiectomy

- No finasteride within past 30 days (90 days for dutasteride)

- No prior or concurrent cytotoxic chemotherapy for prostate cancer

- Prior chemotherapy for a different cancer allowed

- No prior radiotherapy (RT), including brachytherapy, to the region of the study cancer
that would result in overlap of RT fields

- Patients undergoing brachytherapy must have transrectal ultrasound confirmation
of prostate volume < 60 cc, American Urological Association (AUA) score ≤ 15
within the past 60 days of registration, and no history of prior transurethral
resection of the prostate (TURP)

- TURP allowed for patients who receive external-beam radiation therapy only