Evaluation of squamous cell carcinoma antigen-immunoglobulin M complex (SCCA-IGM) and alpha-L-fucosidase (AFU) as novel diagnostic biomarkers for hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) surveillance lacks a reliable biomarker. Alpha-fetoprotein (AFP) is the most widely used. However, not all HCCs secrete AFP. AFP may be elevated with cirrhosis in the absence of HCC. Serum alpha-L-fucosidase (AFU) and squamous cell carcinoma antigen-immunoglobulin M complex (SCCA-IgM) were found to be useful markers in diagnosing HCC. SCCA-IgM and AFU were assessed by ELISA technique; AFP was measured by enzyme chemiluminescence in serum of 40 patients with HCC, 30 patients with liver cirrhosis, and 20 healthy control participants to compare their accuracy in early diagnosis of HCC. Serum SCCA-IgM and AFU levels were significantly elevated in HCC group compared to cirrhotic group (P value<0.001 and <0.001, respectively). Receiver operating characteristic curve showed the optimal cutoff value for SCCA-IgM was 233 AU/ml with sensitivity 87.5% and specificity 66% and for AFU was 25 U/L with sensitivity 87.5% and specificity 98%. AFP cutoff value was 48 ng/mL with sensitivity of 70% and specificity of 53.3%. The simultaneous determination of AFP and SCCA-IgM activity increased the sensitivity to 92.5% and specificity to 62.1%. There were positive significant correlations between SCCA-IgM and each of AFU (r=0.296, P=0.005) and AFP (r=0.284, P=0.007) and no correlation between AFP and AFU. All markers did not correlate with the tumor size or affected by the Child score. The significant difference between SCCA-IgM and AFU levels among HCC and cirrhotic patients suggests their use as potential diagnostic tools and allows identifying a new group of HCC patients even in the absence of elevated AFP.