Vaccine Therapy in Treating Patients With Cancer of the Gastrointestinal Tract

RATIONALE: Vaccines may make the body build an immune response to kill tumor cells. PURPOSE: Randomized phase II trial to compare the effectiveness of two different vaccines in treating patients who have cancer of the gastrointestinal tract.

OBJECTIVES: * Determine whether immunization with carcinoembryonic antigen (CEA) peptide 1-6D (CAP 1-6D) emulsified in Montanide ISA-51 adjuvant or dissolved in sargramostim (GM-CSF) can generate CAP 1-6D-specific T cells in patients with CEA-producing adenocarcinomas of gastrointestinal tract origin. * Determine whether vaccination with CAP 1-6D can generate cytotoxic T cells against CEA-expressing tumors in these patients. * Determine whether this vaccine can produce antitumor responses in these patients. * Determine the frequency and severity of toxic effects associated with this vaccine in these patients. OUTLINE: This is a randomized study. Patients are randomized to 1 of 2 treatment arms. * Arm I: Patients receive carcinoembryonic antigen peptide 1-6D (CAP 1-6D) emulsified in Montanide ISA-51 adjuvant subcutaneously on day 1. * Arm II: Patients receive CAP 1-6D dissolved in sargramostim (GM-CSF) intradermally on day 1. Treatment repeats in both arms every 3 weeks for 6 courses in the absence of disease progression or unacceptable toxicity. Patients are followed at 3 weeks and then as necessary. PROJECTED ACCRUAL: A total of 10-36 patients (5-18 per arm) will be accrued for this study within 36 months.