S0114 Vaccine Therapy in Treating Patients With Gastric, Prostate, or Ovarian Cancer

DISEASE CHARACTERISTICS: * Histologically confirmed diagnosis of one the following: * Stage II-IV gastric cancer * Stage IIC-IV ovarian cancer in first complete remission * CA 125 normal and stable\* * Grade III anaplastic astrocytoma * Stage IV (M1) prostate adenocarcinoma * No small cell variations * No biochemical progression after definitive surgery, defined by the following: * Prostate-specific antigen more than 0.4 ng/mL which remains elevated on 2 additional measurements at least 2 weeks apart after prostatectomy * Three consecutive rises in PSA, each at least 1 month apart after definitive radiotherapy * Must be receiving androgen blockade * PSA less than 5 ng/mL and stable\* * Documented EGFRvIII expression in primary tumor * Must have received prior surgery and or chemoradiotherapy for disease (except prostate cancer patients) NOTE: \*Stable defined as no increase over 2 measurements at least 28 days apart with the last measurement within the past 28 days PATIENT CHARACTERISTICS: Age: * 80 and under Performance status: * Zubrod 0 Life expectancy: * Not specified Hematopoietic: * WBC at least 3,000/mm\^3 * Platelet count at least 100,000/mm\^3 * Hemoglobin at least 10 g/dL Hepatic: * SGOT no greater than 2.5 times upper limit of normal (ULN) * Alkaline phosphatase no greater than 2.5 times ULN * No hepatitis Renal: * Not specified Other: * No other malignancy in the past 5 years except adequately treated basal cell or squamous cell skin cancer, carcinoma in situ of the cervix, or adequately treated stage I or II cancer in complete remission * No contraindication to receiving sargramostim (GM-CSF) or KLH-based vaccine products * No autoimmune disease * HIV negative * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception PRIOR CONCURRENT THERAPY: Biologic therapy: * Not specified Chemotherapy: * See Disease Characteristics * At least 1 month since prior cytotoxic chemotherapy * No concurrent chemotherapy Endocrine therapy: * See Disease Characteristics * At least 1 month since prior treatment dose corticosteroids * No concurrent corticosteroids Radiotherapy: * See Disease Characteristics * No concurrent radiotherapy Surgery: * See Disease Characteristics Other: * Recovered from all prior therapies * No concurrent enrollment on other phase I studies * No other concurrent immune modulators