The purpose of this research is to help us study a vaccine treatment for patients with prostate cancer. A vaccine is a medicine that teaches the body to destroy harmful infections and other foreign substances. The immune system is made up of many different types of cells, which fight infection and disease in your body. A vaccine may stimulate the immune system to destroy the cancer cells. It may also help to slow the growth of the cancer. The vaccine is a solution given as an injection given into or under the skin. It is made up of several parts. The first part is MUC-2, a protein present in many cancers, especially prostate cancer. MUC-2 is attached to a material called KLH or keyhole limpet hemocyanin. KLH is purified from a snail- like marine mollusk called a keyhole limpet and has been used for many years to boost immune responses in animals and in people. Attaching MUC-2 to KLH helps the immune system react to MUC-2. The mixture of MUC-2 attached to KLH is in turn mixed with a material called QS21, from the bark of a tree, which also helps the immune system to make more cancer- fighting cells. A vaccine like the one you will receive has been given to laboratory animals and been shown to produce an immune response in these animals.

Inclusion Criteria:

• Patients with prostate cancer that is histologically confirmed by the Department of Pathology at MSKCC will be considered if they show progression of disease based on biochemical parameters. Patients with radiographic evidence of disease are not eligible.
• Hormonal status will be recorded on the basis of serum testosterone levels.
• Patients who have progressed after primary therapy to include surgery or radiation (with or without neo-adjuvant androgen ablation), or intermittent hormonal treatment who have non-castrate levels of testosterone (>50 ng/ml). Patients with soft tissue and/or bone disease or patients who are androgen- independent with no evidence of radiographic disease are not eligible. Those patients who are symptomatic or who are anticipated to develop symptoms within 6 months of entry will be excluded.
• Patients should have no change in their hormone therapies (with the exception of therapies needed to maintain castrate levels of testosterone), including prednisone or dexamethasone within two weeks prior to entry into study.
• Patients must have evaluable disease (by serial changes in PSA).
• Karnofsky performance status >60%.
• Patients must have adequate organ function as defined by:
• WBC > or = to 3500/mm3 platelet count > or = to 100,000 mm3.
• Bilirubin < or = 2.0 rag/100 ml or SGOT <3.0 X's the upper limit of normal.
• Creatinine < or = 2.0 mg/100 ml or creatinine clearance > or = 40 cc/min.
• Patients must have recovered from the toxicity of any prior therapy, and not received chemotherapy or radiation therapy for at least 4 weeks prior to entry into the trial.
• No history of an active secondary malignancy within the prior five years except for nonmelanoma skin cancer.
• Patients must be at least 18 years of age.
• Patients who have previously received suramin, may be treated if they have been off this drug for at least 8 weeks and/or ha ve a documented plasma concentration below 50 mg/ml. For these patients, replacement doses of hydrocortisone are permitted.
• Patients must sign informed consent.
• Registration to IRB Protocol 90-40 (Correlative studies in human prostate cancer).

Exclusion Criteria:

• Clinically significant cardiac disease (New York Heart Association Class III/IV), or severe debilitating pulmonary disease.
• Active CNS or epidural tumor.
• An infection requiring antibiotic treatment.
• Narcotic dependent pain.
• Anticipated survival of less than 6 months.
• Positive stool guaiac excluding hemorrhoids or history of documented radiation induced proctitis.
• Allergy to seafood.
• Patients with radiographic evidence of metastatic disease.