Clinical evaluation of thyroxine-binding globulin (TBG) as a marker of liver tumors

This investigation was undertaken to evaluate thyroxine-binding globulin (TBG) as a marker of liver tumors, in conjunction with the liver scintigram. Of 30 patients with primary hepatocellular carcinoma (PHC), 22 (73.3%) showed significantly higher TBG concentrations. Eight patients (26.7%) showed normal TBG concentrations. In the case of 27 out of 30 patients with definite liver tumors, defects were apparent on the scintigrams. But seven of them had normal TBG concentrations in spite of the defects on the scintigrams. Out of 33 postoperative patients with liver metastasis, 28 (84.8%) had a raised TBG concentration. Only five (15.2%) had a normal TBG level. In 31 patients (93.9%) out of 33 with liver metastasis, a definite diagnosis was made on the basis of the liver scintigram. In 28 (90.3%) of these 31 people, the TBG concentration was higher than normal. Among 63 patients with liver tumors, both primary and metastatic, the test sensitivity for liver tumors was 92.1% (58/63) based on the accuracy of the liver scintigram. It was 79.4% (50/63) based on the TBG measurement. Why TBG increases to such an extent in spite of the euthyroid state remains unexplained. But it may be concluded that elevated TBG with positive liver scintigram furnishes a sensitive, fairly reliable, nonspecific tumor marker to determine liver tumors, especially in the case of liver metastasis.