Expression of the Carbohydrate Tumor Marker Sialyl Lewis a (Ca19-9) in Squamous Cell Carcinoma of the Larynx

The clinical relevance of the carbohydrate antigen Sialyl Lewis a (SLea) as a serum tumor marker in diagnosis and follow-up treatment is unquestioned in a broad spectra of human carcinomas. Overexpression of this antigen is combined with poor prognosis and malignant relapse. The aim of our study was the systematic investigation of SLea expression in squamous cell carcinoma of the larynx versus normal and phlogistic tissue. Paraffin-embedded sections of normal, phlogistic and squamous cell carcinoma tissue were incubated with a monoclonal antibody against SLea. The staining reaction was performed using ABC-Peroxidase and DAB. As a positive control tissue of breast cancer was used and the negative control was performed with unspecific mouse IgM. Semiquantitative evaluations were carried out double-blinded by two independent investigators, including a pathologist. A very faint expression of SLea (Ca19-9) in normal laryngeal tissue, a moderate upregulation in phlogistic tissue and a dramatic upregulation in some types of squamous cell carcinoma of the larynx were observed. Laryngeal cancer is the most common cancer of the upper aerodigestive tract. Most cases of laryngeal cancer are squamous cell carcinoma and can be classified into: well differentiated (more than 75% keratinization), moderately differentiated (25-75% keratinization), and poorly differentiated (