Gamma-glutamyl transpeptidase as an aid in the diagnosis of liver metastases.

Serum gamma-glutamyl transpeptidase (GGTP) activity was examined in 79 patients. Of these, 49 had diverse malignant tumors, some of which had metastasized to the liver, and 18 had benign diseases of the liver, gallbladder and bile ducts. Enzyme activity increased significantly in all but two patients in whom liver metastases were found. All but one of the patients with malignant tumors, but without liver metastases, showed normal GGTP activity. GGTP activity was elevated in all cases of jaundice. In the absence of jaundice, elevated GGTP activity is suggestive of the presence of liver metastases.