Progressive increase of SCCA-IgM immune complexes in cirrhotic patients is associated with development of hepatocellular carcinoma

About 3-4% of cirrhotic patients develop primary liver cancer every year. Specific serologic markers have not yet been identified for screening of high risk patients. The serpin squamous cell carcinoma antigen (SCCA) is overexpressed in liver cancer and circulating SCCA-IgM complexes have been described in patients with hepatocellular carcinoma (HCC). The aim of the present study was to assess the behavior of SCCA-IgM in relation to HCC development in patients with cirrhosis. A retrospective, longitudinal study was conducted in a cohort of prospectively followed cirrhotic patients. Two groups with similar clinical profile at presentation were studied : group A included 16 patients who developed HCC during a median follow up of 4 years; group B included 17 patients who did not develop HCC during the same time interval. Circulating SCCA-IgM immune complexes were determined using a recently standardized ELISA assay. At presentation similar levels of SCCA-IgM complexes mean +/- SD: 267.40 +/- 382.25 U/ml vs. 249.10 +/- 446.90 U/ml, p = 0.9006] and of alpha-fetoprotein AFP; 24.11 +/- 59.04 IU/ml vs. 10.91 +/- 23.34 IU/ml, p = 0.3995] were detected in group A and in group B. The increase over time (phi) of SCCA-IgM, assessed within at least one year before clinical diagnosis of HCC, was remarkably higher in group A than in group B (mean +/- SD = 280.05 +/- 606.71 (U/ml)/year vs. -37.92 +/- 95.94 (U/ml)/year, p = 0.0408), while AFP increase was not significantly different (11.89 +/- 23.27 (IU/ml)/year vs. 3.67 +/- 11.46 (IU/ml)/year, p = 0.2179). Receiver operating characteristic (ROC) curves were plotted for the rate of change in the levels of both markers and the diagnostic accuracy measured as AUROC was higher for SCCA-IgM phi (0.821) than for AFP phi (0.654). In conclusion, the progressive increase of SCCA-IgM over time was associated with liver tumor development, suggesting that monitoring the behavior of SCCA-IgM might become useful to identify cirrhotic patients at higher risk of HCC development.