Abstract

The recognition that human tumours release a wide variety of substances has renewed interest in biochemical tests which might be of use in the diagnosis and monitoring of cancer. Carcinoembryonic antigen (CEA) is a glycoprotein produced by the alimentary tract, liver and pancreas of fetuses between the second and sixth months of intrauterine life, and by certain human tumours.¹ Early studies indicated an apparent specificity of CEA for intestinal and, in particular, colorectal carcinomas, but later work with a more sensitive assay system showed that CEA or CEA-like materials are normally present in the blood, gut and some other issues, can be released into the blood in excess during some inflammatory and regenerative diseases and are produced by a wide variety of different tumours.² Estimations of plasma CEA levels by radioimmunoassay are available in the United Kingdom through the Supra-Regional Assay Service.³