Serum monomeric laminin-γ2 as a novel biomarker for hepatocellular carcinoma

The diagnosis of hepatocellular carcinoma (HCC) in the early stages is important for successful clinical management. Laminin (Ln)-γ2 expression has been reported in various types of malignant carcinomas. We recently developed a highly sensitive method to measure serum monomeric Ln-γ2 levels using a fully automated chemiluminescent immunoassay (CLIA). Using our CLIA, we evaluated its diagnostic value in sera from patients with chronic liver disease (CLD) and patients with hepatocellular carcinoma (HCC). Serum alpha-fetoprotein (AFP) and des-gamma-carboxy prothrombin (DCP) were also examined in these subjects. Median levels of Ln-γ2 were significantly higher in patients with HCC (173.2 pg/mL; range: 39.5-986 pg/mL) compared with patients with CLD (76.7 pg/mL; range: 38.7-215.9 pg/mL) and with healthy volunteers (41.1 pg/mL; range: 10.9-79.0 pg/mL). The optimal cutoff value for Ln-γ2 that allowed us to distinguish between HCC and nonmalignant CLD was 116.6 pg/mL. Elevated Ln-γ2 levels were observed in 0% of healthy volunteers, 17% of patients with CLD, and 63% of patients with HCC. The positivity rate in patients with HCC for the combination of Ln-γ2 and DCP was 89.5%, which was better than that for either of the two markers alone (63% and 68%, respectively). Among patients with early-stage HCC (T1 or T2), the positivity rates for monomeric Ln-γ2, AFP and DCP were 61%, 39% and 57%, respectively. Serum Ln-γ2 may be a potential biomarker for HCC surveillance. The combination of Ln-γ2 and DCP may be more sensitive for laboratory diagnosis of HCC than the combination of AFP and DCP.