Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed prostate cancer

- Stage D0 disease

- Disease limited to the prostate

- Seminal vesicle involvement allowed provided all visible disease was
removed by surgery

- Rising prostate-specific antigen (PSA) after completing primary local therapy
(surgery and/or radiotherapy) for prostate cancer ≥ 3 months ago

- PSA ≥ 2 ng/mL documented by 2 measurements taken ≥ 4 weeks apart with a doubling
time of ≤ 8 months

- Final PSA measurement must be obtained within 1 week prior to study entry

- Negative CT scan of the chest, abdomen, and pelvis and bone scan

- Scans must be completed within 4 weeks prior to study entry

PATIENT CHARACTERISTICS:

Age

- 18 and over

Performance status

- ECOG 0-2

Life expectancy

- At least 6 months

Hematopoietic

- Absolute neutrophil count ≥ 1,500/mm^3

- Platelet count ≥ 100,000/mm^3

- Hemoglobin ≥ 10 g/dL

Hepatic

- SGOT and SGPT ≤ 1.5 times upper limit of normal

- Bilirubin ≤ 1.5 mg/dL

- No uncontrolled hepatic disease

Renal

- Creatinine ≤ 1.5 mg/dL

- No uncontrolled renal disease

Cardiovascular

- No uncontrolled cardiac disease

Other

- Fertile patients must use effective barrier contraception during and for 4 weeks
after completion of study treatment

- No active infection

- No known HIV positivity

- No other uncontrolled medical condition, defined as ≥ grade 3

- No uncontrolled psychiatric disease

- No diagnosis of major depression or suicidal ideation

PRIOR CONCURRENT THERAPY:

Biologic therapy

- Not specified

Chemotherapy

- More than 5 years since prior chemotherapy

- No prior treatment with cyclophosphamide or etoposide that lasted for > 2 months

Endocrine therapy

- At least 1 year since prior androgen-ablation therapy and recovered

- No disease progression during therapy

Radiotherapy

- See Disease Characteristics

- Recovered from prior radiotherapy

Surgery

- See Disease Characteristics

- Recovered from prior surgery

Other

- No other concurrent investigational agents

- No concurrent cyclosporine, succinylcholine chloride, or phenobarbital