Elevated Serum YKL-40 Level Predicts Poor Prognosis in Hepatocellular Carcinoma After Surgery

YKL-40 is a member of the mammalian chitinase-like proteins. Elevated serum YKL-40 levels in patients with gastrointestinal cancer at time of diagnosis are associated with poor prognosis. The aim of this study is to evaluate the prognostic value of serum YKL-40 before surgery and during follow-up in hepatocellular carcinoma (HCC) patients receiving curative resection. Serum YKL-40 levels were determined by enzyme-linked immunosorbent assay. Overall and recurrence-free survival (RFS) curves were constructed using the Kaplan-Meier method and compared by the log-rank test. A Cox proportional-hazards regression model was performed to identify independent prognostic factors. Median follow-up time was 35 months. Baseline serum YKL-40 was elevated in 56% of patients with HCC receiving curative resection. Patients with elevated serum YKL-40 had significantly shorter overall and RFS than patients with normal serum YKL-40 (P = 0.003 and P = 0.001, respectively). Multivariate Cox regression analyses indicated that baseline serum YKL-40 was an independent prognostic variable for overall and RFS [hazard ratio (HR) = 1.968, 95% confidence interval (CI): 1.093-3.543, P = 0.024; HR = 1.891, 95% CI: 1.106-3.232, P = 0.020; respectively]. After curative resection, high serum YKL-40 (log-transformed continuous variable) within 6 months predicted significantly poorer overall survival (HR = 3.003, 95% CI: 1.323-6.817, P = 0.009). This study indicated that serum YKL-40 was an independent prognostic factor for overall and RFS in HCC patients receiving curative resection. Serial monitoring of serum YKL-40 after curative resection may provide prognostic information.