Increased serum autotaxin levels in hepatocellular carcinoma patients were caused by background liver fibrosis but not by carcinoma.

BACKGROUND: Controversy exists as to whether autotaxin (ATX) may be importantly associated with pathophysiology of hepatocellular carcinoma (HCC).

METHODS: We evaluated serum ATX levels and its mRNA expression in consecutive 148 HCC patients treated with radiofrequency ablation (RFA) and 30 patients with hepatic resection.

RESULTS: Although increased serum ATX levels were observed in almost all the patients treated with RFA, they were not reduced after RFA. Furthermore, serum ATX levels were associated not with tumor burden but with the parameters predicting for liver fibrosis, such as liver stiffness values. Then, in surgically-treated patients, there was no significant correlation between serum ATX levels and ATX mRNA expression levels in HCC tissues. Notably, ATX mRNA expression levels in HCC tissues were not higher than those in peri-tumorous tissues. Finally, serum ATX levels in surgically-treated HCC patients were rather correlated with ATX mRNA expression levels in peri-tumorous tissues as well as with liver fibrosis stage.

CONCLUSION: The increase in serum ATX levels in HCC patients may not be caused by abundant ATX production in HCC tissues but by fibrosis in the background livers.