Gamma-glutamyl transpeptidase in cancer diagnosis.

Serum gamma-glutamyl transpeptidase ( G G T ), alkaline phosphatase (A L P ) and aspartate aminotransferase (A ST) were assayed in patients with cancer. GGT was more sensitive than either ALP or AST in detecting metastatic car­ cinoma to the liver in both icteric and anicteric patients with cancer. Extremely high activities of GGT were seen in patients with hepatoma, carcinoma of the pancreas and of the gallbladder. In patients with metastatic carcinoma to the bone, serum ALP was uniformly elevated, but GGT was either normal or only modestly elevated compared to ALP. Abnormally high elevations in GGT activ­ ity in patients with cancer is strongly suggestive of hepatic involvement.