RATIONALE: Diagnostic procedures, such as radionuclide imaging using bispecific antibody, may help find colorectal cancer cells and learn the extent of disease.

PURPOSE: This phase I trial is studying how well a bispecific antibody works in finding tumor cells in patients with colorectal cancer.

OBJECTIVES:

• Assess the pharmacokinetics and tissue distribution of anti-CEA x anti-HSG bispecific monoclonal antibody TF2 in patients with colorectal cancer.

OUTLINE: This is a multicenter study.

Patients receive iodine I 131-labeled anti-CEA x anti-HSG bispecific monoclonal antibody TF2 (^131I-TF2) IV over 10-20 minutes on day 1. Patients also undergo whole-body external scintigraphy at various times during the study.

Blood samples are collected at baseline and periodically after ^131I-TF2 infusion for pharmacokinetic studies and ^131I-TF2 biodistribution by ELISA and radioactivity measurements.

DISEASE CHARACTERISTICS:

• Histologically confirmed colorectal cancer

  • Radiological documentation of disease is preferred, but not required

PATIENT CHARACTERISTICS:

• Karnofsky performance status 70-100%
• Life expectancy ≥ 3 months
• WBC ≥ 3,000/mm³
• Neutrophil count ≥ 1,500/mm³
• Platelet count ≥ 100,000/mm³
• Serum creatinine normal
• Bilirubin ≤ 1.5 times upper limit of normal (ULN)
• AST/ALT < 2 times ULN
• Not pregnant or nursing
• Fertile patients must use effective contraception during and for 1 month after completion of study therapy
• No medical conditions that might prevent full participation in protocol-required testing or follow-up
• No institutionalized patients (e.g., in prisons or mental health institutions)

PRIOR CONCURRENT THERAPY:

• No concurrent chemotherapy or treatments that would compromise the safety and efficacy of protocol assessments