Agrin as a prognostic biomarker in hepatocellular carcinoma.

Abstract

559 Background: Hepatocellular carcinoma (HCC), the predominant form of hepatic cancer is associated with high mortality rates, both in the United States & globally. Alpha-fetoprotein (AFP) & Glypican-3 have been proposed as biomarkers for HCC, although they do not offer any prognostic benefit to model disease progression. Immunotherapy combinations increase patient survival to ~18 months but are not selected based on biomarkers. Agrin, a secreted proteoglycan is frequently overexpressed & secreted in HCC & plays a prominent role in liver tumor microenvironment to promote hepatocarcinogenesis. In this single center, retrospective study using banked materials, we assessed the role of agrin as a prognostic biomarker in HCC. Methods: With IRB approval, we studied 90 newly diagnosed unresectable hepatobiliary cancer patients, & compared them to healthy controls matched for age, gender, & BMI between February 2006 & September 2013. Serum concentration (conc.) of agrin was assessed using enzyme-linked immunosorbent assay (ELISA). We correlated the level of agrin with AFP, a known biomarker in hepatocellular cancer. Comparisons between groups were made using Mann-Whitney U & Kruskal Wallis tests. Survival analysis used both univariate & multivariate Cox regression models to investigate the relationship between survival outcomes & agrin concentration, in comparison to AFP. Results: Mean circulatory plasma agrin levels were higher in HCC patients (n=79) (7.97 ng/ml, SD 5.8) when compared to controls (4.27 ng/ml, SD 1.03). ECOG PS > 2 was linked to higher agrin conc. (mean: 10.5 ng/ml, p 0.007). While agrin levels in healthy individuals did not change with smoking history, the mean agrin levels were significantly higher in smokers (9.49 ng/ml) vs non-smokers (6.84 ng/ml) (p 0.0001) amongst HCC patients. Agrin displayed a strong positive correlation with AFP (correlation coefficient (r) 0.31944, p 0.0137). Multivariate cox regression models indicated that agrin conc. of > 9.3 ng/ml had greater predictable survival outcomes (Hazard ratio (HR) 8.51, p <0.001) when compared to elevated AFP levels (HR 1.55, p 0.25) (Table). HCC patients with lower agrin conc. (4.9 to 6.3 ng/ml) exhibited a one-year survival rate of 63% & a median survival time of 16 months, while those with higher agrin conc. exceeding 9.3 ng/ml had significantly lower one-year survival rate of 14% & significantly shorter median survival time of 3 months (p 0.002). Conclusions: Our results suggest that agrin levels as a prognostic indicator fare better than AFP levels. Thus, further studies should be done to explore this as a therapeutic target and as a biomarker of response to targeted therapies. [Table: see text]