Inclusion Criteria

DISEASE CHARACTERISTICS: Histologically confirmed prostate cancer Disease progression with
3 or more rising PSA levels at least 2 weeks apart with greater than 50% rise above the
baseline PSA, despite prostatectomy or radiotherapy Disease progression following primary
therapy including surgery or radiotherapy with or without neoadjuvant androgen ablation
allowed OR Intermittent hormonal therapy with noncastrate levels of testosterone (greater
than 50 ng/mL) allowed No soft tissue and/or bone disease OR No androgen independence
without evidence of radiographic disease No change in hormonal therapies (excluding
therapies to maintain castrate testosterone levels) including prednisone or dexamethasone
within 2 weeks of study No symptomatic or anticipatory (within 6 months) symptomatic
disease No active CNS or epidural tumor No radiographic evidence of metastatic disease

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 70-100% Life
expectancy: At least 6 months Hematopoietic: WBC at least 3,500/mm3 Platelet count at
least 100,000/mm3 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 New York Heart Association class III or IV heart
disease Pulmonary: No severe debilitating pulmonary disease Other: No other active
malignancy within the past 5 years except nonmelanoma skin cancer No infection requiring
antibiotics No seafood allergies No positive stool guaiac except for hemorrhoids or
history of radiotherapy induced proctitis No narcotic dependent pain

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: At least 4 weeks
since prior chemotherapy and recovered At least 8 weeks since prior suramin and/or plasma
concentration below 50 microgram/mL Endocrine therapy: See Disease Characteristics
Recovered from prior hormonal therapy Concurrent replacement hydrocortisone following
prior suramin allowed Radiotherapy: See Disease Characteristics At least 4 weeks since
prior radiotherapy and recovered Surgery: See Disease Characteristics Recovered from prior
surgery