"Humors from Tumors": Carcinoembryonic Antigen, Alpha-Fetoprotein, and Digestive System Cancer

Excerpt

There is a growing list of tumor-associated fetal substances that show diagnostic promise and may in time have immunotherapeutic and prophylactic value (1, 2). Malignancies of the digestive system have received special attention in this regard, especially since 1965, when Gold and Freedman (3) identified a tumor-specific glycoprotein antigen in human colonic carcinomas. This so-called carcinoembryonic antigen (CEA) is also present in other adenocarcinomas of entodermally derived digestive system epithelium, as well as in human fetal and embryonic gut, pancreas, and liver during the first two trimesters of pregnancy (4). The antigen is a predominantly carbohydrate material with a molecular