Prognostic significance of CEA immunoreactivity patterns in large bowel carcinoma tissue

In order to determine the clinical value of CEA detection in large bowel cancer tissue the patterns rather than the intensity of immunoreactivity of CEA reactive antibodies were analyzed in 312 large bowel cancer patients especially in relation to patient survival. CEA immunoreactivity appeared to be distinguishable into a predominantly apical/cytoplasmic and a predominantly membranous pattern. Twenty-four (7.7%) tumours were found to be CEA negative or only focally positive. Two hundred and eighty-three (90.7%) of the carcinomas showed a predominantly apical/cytoplasmic immunoreactivity pattern, whereas 5 (1.6%) of the tumours revealed mostly membranous CEA immunoreactivity. CEA negative or focally positive carcinomas and CEA positive tumours with membranous immunoreactivity were significantly more often observed in the group of poorly differentiated carcinomas (P greater than 0.001), but showed no significant correlation with stage of tumour extension (P = 0.11). Also, these carcinomas demonstrated a more aggressive course in patients compared to CEA positive tumours with an apical/cytoplasmic CEA expression pattern. We, therefore, conclude that determination of the pattern of CEA immunoreactivity in large bowel cancer tissue may enable the detection of subgroups of patients with a poor prognosis.