Circulating interleukin-6 as a tumor marker for hepatocellular carcinoma

Background: A large amount of evidence suggests a possible role of interleukin-6 (IL-6) in the pathogenesis of hepatocellular carcinoma (HCC). Patients and methods: We studied both IL-6 and A₁FP in patients with HCC, non-neoplastic liver disease or in healthy controls. Results: IL-6 titers were four-fold higher in cancer than in cirrhotic patients and 25-fold higher than in healthy controls. As for alpha1-fetoprotein (A₁FP) titers, the highest levels were observed in cancer patients. Receiver operating characteristic (ROC) curves analysis demonstrated that IL-6 is significantly more discriminant than A₁FP, with 'optimal' cut-off values of 7.9 pg/ml (sensitivity = 0.83, specificity = 0.83, efficiency = 0.83). The ROC curves used to distinguish HCC from cirrhotic patients only, showed higher discriminant power of IL-6 versus A₁FP titers, with a new cut-off value of 12 pg/ml (sensitivity = 0.73, specificity = 0.87, efficiency = 0.8). Discriminant analysis on HCC and non-HCC subjects yielded sensitivity, specificity and efficiency rates of 77%, 93% and 88%, respectively. The overall efficiency of the two tests combined was 82%. Conclusions: IL-6 could be considered a promising tumor marker forHCC. In particular, the diagnostic value of the test is significantly increased when combined with A₁FP.