A study of plasma CEA by a direct radioimmunoassay method in 1704 cases.

: The authors have used an original method of direct radioimmunoassay of plasma CEA for testing plasma of 1704 patients affetected by various neoplastic and non-neoplastic diseases. The percentage of positive results in blood from patients with adenocarcinoma of the gastroenteric tract was 66.8%. The positivity in other non-neoplastic diseases was 2.7%, except for liver cirrhosis and other chronic hepatopathies, which showed 29.6% of positive reactions. The test should be clinically useful in the differential diagnosis of gastro-enteric carcinoma.