CEA radioimmunoassay. Clinical applications in colorectal cancer

Since 1978 carcino-embryonic antigen determinations (CEA) have been used systematically in the preoperative as well as in the postoperative assessment of 139 patients operated for colorectal cancers. From these data results that CEA determination is of poor value for screening purposes, as 30% of the tumors don't produce the specific CEA antigen. High preoperative levels which normalize after operation, are equal to curative resection. The importance of CEA is emphasized in the postoperative follow-up of especially Dukes B and C lesions, where starting from normal base figures, increasing CEA levels are suggesting recurrences, long before their clinical evidence. Serial CEA determinations may show a slow rise, and in these cases a second look procedure can be considered. Clinical examination stays primordial; CEA is a good marker, and on account of the low cost, allows to be inserted in the postoperative follow-up scheme.