Serum levels of gamma-glutamyl transpeptidase in relation to HCC human biology and prognosis.

Background and aim: Hepatocellular carcinoma (HCC) biomarkers are limited, as even the best studied, alpha-fetoprotein (AFP), is elevated in no more than 50% of HCC patients. The aim was to evaluate several serum liver function tests in relation to survival and tumor characteristics in a large cohort of Turkish HCC patients.

Methods: We retrospectively examined the serum levels of gamma glutamyl transpeptidase (GGT) in relation to patient survival.

Results: Kaplan-Meier analysis showed that only GGT and albumin amongst liver function tests, were significantly associated with survival. Survival worsened with increase in GGT levels semi-quantitatively. Increase in GGT levels was also found to significantly correlate with an increase in maximum tumor diameter from 4.5 to 7 cm, a 20-fold increase in serum alpha-fetoprotein level, an increase in tumor multifocality from 20 to 54% of patients, and a doubling in percent of patients with portal vein thrombosis (PVT) from 20 to 40%. Serum GGT levels also showed significant survival differences for patients with low AFP levels. A doublet combination of serum GGT with albumin levels was associated with higher hazard ratios in a Cox regression analysis, as compared with single parameter GGT. The combination parameter pair was also prognostically useful in the low-AFP patient subcohort and was associated with significant differences in patient tumor characteristics.

Conclusions: Serum GGT levels and especially combination serum GGT plus albumin levels, were significantly associated both with HCC patient survival and tumor aggressiveness characteristics, regardless of AFP levels in a large Turkish cohort. This might be especially useful since the majority of HCC patients do not have elevated levels of AFP.