Are circulating CEA immune complexes a prognostic marker in patients with carcinoma of the gastrointestinal tract?

CEA immune complexes and free CEA were determined to 363 patients with histologically confirmed adenocarcinoma of the gastrointestinal tract before surgery and in a post-operative follow-up. Circulating CEA immune complexes (CEA-IC) could be detected preoperatively in 89 patients. Incidence of CEA-IC increased with increasing tumour extension; 72/89 patients with CEA-IC showed already metastatic disease progression, 40/89 had nonresectable tumours. Patients with preoperative CEA-IC had a poorer prognosis than patients without CEA-IC but with high levels of free CEA, or CEA-negative patients. The appearance of CEA-IC with consecutive increases in the postoperative follow-up indicated disease recurrence. In 32/55 relapse cases, circulating CEA-IC were detected postoperatively, all 32 cases developing metastatic spread of disease.