Aim: To investigate whether expression of cancer stem cell (CSC) markers is associated with recurrence and survival in hepatocellular carcinoma (HCC) patients.
Methods: A consecutive series of 90 HCC patients who underwent curative hepatectomy between April 2007 and April 2009 were analyzed. Of the 90 patients, 38 (42%) experienced recurrence within two years of surgery. To adjust for baseline differences between this early recurrence group and the other patients, propensity-score matching was used to generate 25 pairs of patients. Immunohistochemistry was used to compare expression of CD133, CD90, and epithelial cell adhesion molecule (EpCAM) in liver tissues from propensity score-matched patients and from 10 healthy adults. Associations of the three markers with HCC, clinicopathological characteristics, early recurrence, and survival time were explored.
Results: The expression of all three CSC markers was significantly higher in HCC tissue than in healthy liver tissue (P < 0.001 for all). Among the HCC clinicopathology characteristics examined, the absence of tumor capsule was associated with CD133 expression (P = 0.005); higher histopathology grade and larger tumor size were associated with CD90 expression (P = 0.010 and 0.034, respectively); and elevated serum alpha-fetoprotein levels were associated with EpCAM expression (P = 0.021). Expression of CD90 and EpCAM was significantly higher in the early recurrence group than in other patients (P = 0.001 and 0.045, respectively), whereas CD133 expression was not significantly different between the two groups (P = 0.440). Multivariate analysis identified only CD90 expression as significantly associated with early recurrence. Log-rank analysis identified expression of both CD90 and EpCAM as significantly associated with survival time of HCC patients. Cox regression identified EpCAM expression as an independent predictor of survival time.
Conclusion: Expression of CD133, CD90, and EpCAM CSC markers may be linked to HCC tumor onset and/or progression. In addition, EpCAM expression is associated with shorter survival time, while CD90 expression is associated with early HCC recurrence.
Keywords: CD133; CD90; Cancer stem cells; Epithelial cell adhesion molecule; Hepatocellular carcinoma.