The pattern of gamma-glutamyl transpeptidase, alkaline phosphatase, serum glutamyl oxalate transaminase and serum glutamyl pyruvate transaminase in patients with disseminated non-seminomatous testicular tumors.

The serum enzyme activities of gamma-glutamyl transpeptidase (GGT), alkaline phosphatase (AP), serum glutamyl oxalate transaminase (sGOT) and serum glutamyl pyruvate transaminase (sGPT) were determined longitudinally in 51 patients with a disseminated non-seminomatous testicular tumor. Elevated levels of one or more enzymes before chemotherapy were observed in 13 patients, all with stage III disease. If, after two cycles of chemotherapy, the established tumor markers alpha-fetoprotein (AFP), human chorionic-gonadotropin (HCG) and/or lactate dehydrogenase (LDH) were normalized, the initially increased enzyme activities were declined to normal values as well. Peaking concentrations of one or more of the tumor markers during induction chemotherapy, probably due to tumor cell lysis, were found in 34 of 45 marker-positive patients (76%). In addition, increases of one or more of the investigated enzyme activities were also noticed in 20 patients. In 76% of these patients the highest point of the tumor marker concentration coincided well with that of the enzyme activities. Indications are given that the peak activities were probably not caused by liver damage. Enzyme elevations were also found in 3 out of 7 patients with progressive disease. The behaviour of the enzyme activities of GGT, AP, sGOT and sGPT in patients with a disseminated non-seminomatous testicular tumor coincided with the known tumor markers. It favors the hypothesis that these enzymes are synthesized in the tumor. The mortality amongst stage III patients with or without initially raised GGT levels differed significantly (P less than 0.02). Finally, it is concluded that in patients with a non-seminomatous testicular tumor, sGOT, sGPT, GGT and AP cannot be used to diagnose liver function.