Expression pattern of squamous cell carcinoma antigen in oesophageal dysplasia and squamous cell carcinoma.

The aim of the present study was to evaluate the tissue expression of squamous cell carcinoma antigen (SCCA) in oesophageal dysplasia and squamous cell carcinoma (SCC) with reference to its clinico-pathologic and prognostic significance. Immunohistochemistry using SCCA polyclonal antibody was performed on SCCs from 61 surgical oesophagectomies. Fifteen cases of low-grade dysplasia (LGD) and 37 non-coexistent high-grade dysplasia (HGD) were also sampled from these materials, together with sixteen chronic cases of oesophagitis. SCCA immunoreactivity was present in the maturative compartments of all normal epithelia and oesophagitis. LGDs showed no SCCA immunoreactivity in the dysplastic proliferative component but only in the superficial normal layers. In 94.6% of HGDs, no SCCA immunoreactivity was detected throughout the thickness of the epithelium. In SCCs, SCCA expression higher than 25% was found in 54% of cases. SCCA positivity showed an inverse correlation with histological grade, whereas no statistically significant correlation was found with TNM classifications, stage, or survival. SCCA is not expressed in early oesophageal carcinogenesis but, in SCC, it represents an indicator of histologic differentiation. In differentiated SCC, SCCA may represent a negative factor for cancer invasiveness, through inhibition of proteases.