The role of cytokines in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a frequent malignancy worldwide with a high rate of metastasis. The hepatitis B and C viruses are con- sidered major etiological factors associated with the development of HCC, particularly as a result of their induction of chronic inflammation. There is increasing evidence that the inflammatory process is inherently associated with many different cancer types, including HCC. Specifically, this review aims to cover evidence for the potential roles of cyto- kines, an important component of the immune sys- tem, in promoting HCC carcinogenesis and pro- gression. A global summary of cytokine levels, functions, polymorphisms, and therapies with re- gard to HCC is presented. In particular, the role of proinflammatory Th1 and anti-inflammatory Th2 cytokine imbalances in the microenvironment of HCC patients with metastasis and the possible clin- ical significance of these findings are addressed. Overall, multiple studies, spanning many decades, have begun to elucidate the important role of cy- tokines in HCC. J. Leukoc. Biol. 80: 1197-1213; 2006.