Inclusion Criteria

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