DISEASE CHARACTERISTICS: Histologically confirmed primary colorectal cancer Candidate for a clinically indicated laparotomy for primary tumor resection, resection of hepatic metastases, or placement of an intrahepatic arterial catheter No active CNS metastases defined by new or enlarging lesions on CT scan or within 3 months of treatment (i.e., surgery or radiotherapy) for brain metastases No prior participation in this study

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 70-100% Life expectancy: At least 3 months Hematopoietic: Granulocyte count at least 2,500/mm3 Lymphocyte count greater than 700/mm3 Platelet count at least 100,000/mm3 Hepatic: ALT/AST no greater than 3 times upper limit of normal Bilirubin less than 2 mg/dL Renal: Creatinine no greater than 2.0 mg/dL Other: No pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception No incomplete healing at an incision site as evidenced by incomplete granulation, infection, or localized edema No active infections requiring antibiotics No bleeding disorders No other serious illness that may potentially interfere with obtaining accurate study results No autoimmune disease No hypertrophic skin conditions

PRIOR CONCURRENT THERAPY: Biologic therapy: At least 4 weeks since prior immunotherapy No prior murine, chimeric, or humanized antibody and/or antibody fragment Chemotherapy: At least 4 weeks since prior chemotherapy Endocrine therapy: No concurrent systemic corticosteroids except for acute management of allergic type events Radiotherapy: See Disease Characteristics Surgery: See Disease Characteristics Recovered from prior surgery Other: At least 4 weeks since other prior investigational agents No concurrent immunosuppressive agents