[Experiences with determining carcinoembryonic antigen in tumors of the digestive tract].

CEA levels (CEA = carcino-embryonic antigen) were checked as indicators for the presence of malignant diseases of the gastro-intestinal tract. Tests were applied to 1,102 blood samples, including 1,012 relating to malignant alterations of the digestive tract and 32 relating to benign changes. Sixty-eight samples were taken from tumours localised elsewhere. The importance is stressed of high-continuity observation of CEA levels which have proved to enable dimensional assessment of colorectal carcinoma. Presurgical and postsurgical CEA values can be related to surgical radicality. Regular postoperative monitoring is recommended for prognostication, early detection of recurrences, and early assessment of spreading of the disease.