Abstract
Carcinoembryonic antigen (CEA) radioimmunoassay with sandwich method was performed in addition to both α1 fetoprotein (AFP) radioimmunoassay and liver scintigraphy to elevate the diagnostic accuracy of hepatic tumor in nuclear medicine. All of ten cases with healthy control and 47 out of 52 cases with benign disease showed a CEA titer less than 2.5 ng/ml. On the contrary, 78 out of 188 cases (41%) with malignant disease showed a titer over 2.5 ng/ml, and however most positive cases were metastatic, especially to liver.
In metastatic liver cancer, thirty-three out of 46 cases (72%) showed a strongly positive CEA titer over 5 ng/ml taken as the lower limit predicting the metastasis to liver. On the other hand, in primary liver cancer thirty-two out of 35 cases (91%) showed a strongly positive AFP titer over 200 ng/ml, although only one case showed a CEA titer over 5 ng/ml. Seven cases (15%) with metastatic liver cancer also showed a strongly positive AFP titer, and however six of these positive cases showed a CEA titer over 5 ng/ml.
Furthermore, in metastatic liver cancer, eleven out of 46 cases (24%) showed no clearcut focal defects on liver scintigram. In nine of these negative cases showed a CEA titer over 5 ng/ml, and at subsequent operation metastatic liver lesions were found. The overall diagnostic accuracy for detecting metastatic liver cancer with a combination of both method was 95%.
From present study, CEA radioimmunoassay was useful for the elucidation of the nature of focal hepatic lesions in addition to AFP radioimmunoassay, and moreover could be used as an adjunct to liver scintigraphy for the detection of metastatic lesions in liver.
