Radiolabeled Monoclonal Antibody in Treating Patients With Advanced Colorectal Cancer

DISEASE CHARACTERISTICS: Histologically confirmed advanced colorectal cancer Must have unresectable (Stage IV) disease or have failed or refused conventional chemotherapy Measurable disease by conventional imaging methods Liver involvement no greater than 50% No CNS involvement Not positive for human antimouse antibody titer PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 80-100% Life expectancy: At least 12 weeks Hematopoietic: WBC at least 3,500/mm3 Platelet count at least 150,000/mm3 Prothrombin time less than 1.3 times control Hepatic: Bilirubin no greater than 1 mg/dL Renal: Creatinine no greater than 1.5 mg/dL Cardiovascular: No significant cardiac disease (New York Heart Association class II/IV heart disease) Other: No serious infection requiring treatment with antibiotics No other serious illness Not pregnant or nursing Effective contraception required of all fertile patients PRIOR CONCURRENT THERAPY: Biologic therapy: No prior mouse monoclonal antibody or antibody fragment, chimeric or humanized antibody, or constructs derived from antibodies At least 4 weeks since prior immunotherapy Chemotherapy: No prior mitomycin/radiotherapy combination At least 4 weeks since prior chemotherapy Endocrine therapy: No concurrent steroids or other antiinflammatory agents Radiotherapy: No prior radiotherapy/mitomycin combination Surgery: Not specified