Tissue Carcinoembryonic Antigen in Colorectal Cancer

Abstract

In patients with colorectal cancer, the carcinoembryonic antigen (CEA) levels of cancerous tissue were quantified by radioimmunoassay to determine the relationship among the location of the tumor, the histological type and the blood CEA. In 14 patients with colorectal cancer, the CEA level in the cancerous tissue was significantly higher than in noncancerous tissue. In 15 patients with sigmoid colonic cancer, the tissue CEA was significantly higher than in 22 patients with rectal cancer. Twenty-two patients with normal blood CEA and 19 with elevated blood CEA were compared in terms of their tissue CEA. There was no significant difference between them. There was no significant difference in tissue CEA between 35 patients with well-differentiated adeno-carcinoma and five with moderately differentiated adenocarcinoma. In patients with liver metastasis from colorectal cancer, the frequency of blood CEA levels above 20 ng/ml was significantly higher than that in patients without liver metastasis. The relation between the tissue CEA and the blood CEA was studied in seven patients with colorectal cancer with liver metastasis, from whom specimens of primary tumor and liver metastasis were available. In patients who had liver metastasis and normal blood CEA, there was only one liver metastatic lesion and it was very small. In patients with elevated blood CEA, there were many liver metastatic lesions and they were large. The CEA level in liver metastatic lesions was not always higher than in the primary lesion. It was considered that the levels of CEA in the blood in patients with liver metastasis are affected by the degree of liver metastasis as well as by the CEA level of the primary lesion and the liver metastatic lesion.