Trial of radiolabeled antibody localization in metastases of a patient with a tumor containing carcinoembryonic antigen (CEA)

An attempt to detect metastatic cancer by the specific localization of radiolabeled antibody is reported. The patient had far advanced carcinoma of the colon and a high level of carcinoembryonic antigen (CEA) in serum. She was given whole unabsorbed rabbit antiserum to CEA intravenously, to determine whether CEA can be removed from the circulation. A transient partial depression of the CEA level in serum was obtained, followed by a rebound. Absorbed and purified antibody radiolabeled with 131 I was injected intravenously 19 days later. Total body scans showed no evidence of the localization of the radiolabel in cancer tissue. After another 5 days, injection of the same radiolabeled antibody solution directly into the hepatic artery was attempted. Again, no evidence of localization in liver metastases was obtained. All three infusions of antibody to CEA caused reactions that were ameliorated by Benadryl. Future trials may have better Success if monospecific anti‐CEA is used and patients are chosen who have CEA‐producing tumors, but whose serum CEA levels are low or negative.