Squamous cell carcinoma antigen in human liver carcinogenesis

Background:Squamous cell carcinoma antigen (SCCA) is a serine protease inhibitor that can be overexpressed in hepatocellular carcinoma (HCC) at both molecular and protein level, but no data are available on its expression in pre-malignant stages.Aim:To assess SCCA expression by immunohistochemistry in HCC and its nodular precursors in cirrhotic livers.Methods:55 nodules from 42 explanted livers were evaluated: 7 large regenerative nodules (LRNs), 7 low-grade dysplastic nodules (LG-DNs), 10 high-grade DNs (HG-DNs), and 31 HCC. SCCA expression was semiquantitatively scored on a four-tiered scale.Results:SCCA hepatocyte immunostaining was always restricted to the cytoplasm, mainly exhibiting a granular pattern. Stain intensity varied, ranging from weak to very strong. Within the nodules, positive cells were unevenly distributed, either scattered or in irregular clusters. The prevalence of SCCA expression was 29% in LRNs, 100% in DNs and 93% in HCC. A significant difference emerged in both prevalence and score for LRNs versus LG-DNs (pDiscussion:This study provides the first evidence that aberrant SCCA expression is an early event in liver cell carcinomatous transformation.