[Relapse prognosis for patients with adenocarcinoma of the gastrointestinal tract on the basis of carcinoembryonic antigen (CEA) and its circulating immune complexes (author's transl)].

CEA immune complexes and free CEA were routinely determined in sera of 350 patients with adenocarcinoma of the gastrointestinal tract preoperatively and during a 2-year surveillance period. We could detect circulating CEA immune complexes preoperatively in 25% of our patients. The appearance of CEA immune complexes prove to be a useful prognostic marker with respect to tumor extension since 72/86 patients with CEA immune complexes showed metastasis at the primary resection. The postoperative appearance of CEA immune complexes could be used as an additional parameter for the diagnosis of the relapse; 32/60 patients with a relapse developed CEA immune complexes during the period of surveillance. All patients with localized disease recurrence were found to be free of CEA immune complexes. Detection of CEA immune complexes, however, coincided always with the clinical diagnosis of distant spread of disease. This diagnosis was always preceded by an increase of free CEA and/or CEA immune complexes. In 50/60 patients the relapse could only be demonstrated by clinical methods since these patients stayed CEA-negative throughout the surveillance period.