Radiolabeled Monoclonal Antibody Therapy Plus Peripheral Stem Cell Transplantation in Treating Patients With Metastatic or Recurrent Colorectal Cancer or Pancreatic Cancer

RATIONALE: Radiolabeled monoclonal antibodies can locate tumor cells and deliver tumor-killing substances to them without harming normal cells. Peripheral stem cell transplantation may be able to replace immune cells that were destroyed by monoclonal antibody therapy used to kill tumor cells.
PURPOSE: Phase I/II trial to study the effectiveness of radiolabeled monoclonal antibody plus peripheral stem cell transplantation in treating patients who have metastatic or recurrent colorectal cancer or pancreatic cancer that has not responded to previous treatment.