Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed prostate cancer

- Biochemically progressive disease after primary surgery or radiotherapy with or
without neoadjuvant androgen ablation

- Greater than 50% increase in PSA level above baseline value of 1.0 ng/mL
post-prostatectomy or 2.0 ng/mL post-radiotherapy, based on 3 successive
determinations taken at 2-week intervals

- Patients with prior intermittent hormonal therapy and non-castrate levels of
testosterone are eligible

- Evaluable disease

- No radiographic evidence of metastasis

- No active CNS or epidural tumor

- No soft tissue and/or bone disease

- No androgen-independence with no evidence of radiographic disease

- May not be symptomatic or anticipated to develop symptoms within 6 months of study
entry

- Concurrent registration to protocol MSKCC-90-040 required

PATIENT CHARACTERISTICS:

Age:

- 18 and over

Performance status:

- Karnofsky 70-100%

Life expectancy:

- At least 6 months

Hematopoietic:

- WBC at least 3,500/mm^3

- Platelet count at least 100,000/mm^3

Hepatic:

- Bilirubin less than 2.0 mg/dL OR

- SGOT less than 3 times upper limit of normal

Renal:

- Creatinine no greater than 2.0 mg/dL OR

- Creatinine clearance at least 40 mL/min

Cardiovascular:

- No clinically significant cardiac disease (New York Heart Association class III or
IV)

Pulmonary:

- No severe debilitating pulmonary disease

Other:

- No other prior malignancy within the past 5 years except nonmelanoma skin cancer

- No positive stool guaiac except hemorrhoids or history of documented
radiation-induced proctitis

- No narcotic-dependent pain

- No infection requiring antibiotics

- No requirement for immunosuppressive therapy

- No allergy to seafood

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- Not specified

Chemotherapy:

- At least 4 weeks since prior chemotherapy

Endocrine therapy:

- See Disease Characteristics

- At least 2 weeks since change in hormonal therapy (except to maintain castrate levels
of testosterone), including prednisone or dexamethasone

- At least 8 weeks since prior suramin and/or documented plasma concentration

- of suramin is less than 50 micrograms/mL (replacement hydrocortisone allowed)

Radiotherapy:

- See Disease Characteristics

- At least 4 weeks since prior radiotherapy

- No concurrent radiotherapy to only measurable lesion

Surgery:

- See Disease Characteristics

- No concurrent surgery of only measurable lesion

Other:

- Recovered from prior therapy

- No other concurrent oncolytic agents

- No concurrent immunosuppressive therapy