Utility of Serum YKL-40 as a Tumor-Specific Marker of Hepatobiliary Malignancies

ABSTRACT

BACKGROUND/AIMS: Serum YKL-40 has been linked to several human cancers. We investigated the potential role of serum YKL-40 as a marker of hepatobiliary malignancies. METHODS: Archived serum samples of patients undergoing liver transplantation evaluation at the Mayo Clinic Rochester were used to measure YKL-40 levels. Patients were divided into three groups hepatocellular carcinoma (HCC), cholangiocarcinoma (CCA), and end-stage liver disease (ESLD) without malignancies. The Model for ESLD (MELD) score was used to quantify the severity of liver disease. RESULTS: The median serum YKL-40 level was highest in the ESLD group at 296 ng/mL, compared to 259 ng/mL in the HCC group and 80 ng/mL in the CCA group (p<0.01). There was a significant correlation between the MELD score and serum YKL-40 level (r=0.50, p<0.01). In a multivariate analysis, there was no significant difference in serum YKL-40 level between ESLD and HCC. CCA was associated with lower YKL-40 levels, a finding that was attributable to a lower prevalence of cirrhosis. CONCLUSIONS: The serum YKL-40 level has little utility as a cross-sectional screening tool for hepatobiliary malignancies, namely HCC and CCA. The role of YKL-40 as a surveillance marker in the follow-up of individual patients remains to be determined.