S9921, Hormone Therapy With or Without Mitoxantrone and Prednisone in Patients Who Have Undergone Radical Prostatectomy for Prostate Cancer

DISEASE CHARACTERISTICS:

Histologically confirmed stage T1-T3 adenocarcinoma of the prostate before radical prostatectomy and lymph node dissection

Must have undergone prostatectomy within the past 120 days

Must meet at least 1 of the following pathologic criteria:

Gleason sum at least 8
pT3b (seminal vesicle), pT4, or N1
Gleason sum of 7 and positive margin
Preoperative PSA greater than 15 ng/mL, Gleason score greater than 7, or PSA level greater than 10 ng/mL and Gleason score greater than 6
Must have an undetectable PSA (no greater than 0.2 ng/mL) documented after surgery or prior to adjuvant hormonal therapy (for patients initiating adjuvant hormonal therapy prior to study)
No evidence of metastatic disease on bone scan if PSA is 20 ng/mL or greater at clinical diagnosis
No distant metastatic disease

PATIENT CHARACTERISTICS:

Performance status:

SWOG 0-1

Life expectancy:

Not specified

Hematopoietic:

Not specified

Hepatic:

Not specified

Renal:

Not specified

Cardiovascular:

No uncontrolled congestive heart failure
If history of cardiac disease, LVEF at least 50% by MUGA scan or 2-D echocardiogram

Other:

No HIV positivity
No other prior malignancy within the past 5 years except adequately treated basal cell or squamous cell skin cancer or stage I or II cancer that is currently in complete remission

PRIOR CONCURRENT THERAPY:

Biologic therapy:

Not specified

Chemotherapy:

Not specified

Endocrine therapy:

Prior neoadjuvant hormonal therapy of no more than 4 months duration before radical prostatectomy allowed
Other concurrent adjuvant hormonal therapy allowed if initiated prior to study
Concurrent low-dose megestrol (less than 40 mg/day) for hot flashes allowed

Radiotherapy:

No prior radiotherapy
No concurrent whole pelvis irradiation
Concurrent radiotherapy allowed at the discretion of the physician

Surgery:

See Disease Characteristics
See Endocrine therapy
Recovered from prior surgery

Other:

No other prior or concurrent therapy for adenocarcinoma of the prostate