Detection of cytoskeletal proteins in small cell lung carcinoma

Small cell lung carcinoma (SCLC) is the most aggressive of lung tumors, metastasize widely and are virtually incurable by surgical means. Therefore, the classification of lung cancer into SCLC and non-small cell lung carcinoma is essential for disease prognosis and treatment. For this purpose we have compared the immunohistochemical distribution of different cytoskeletal proteins as tumor markers. Analysis was performed by using of monoclonal antibodies directed against cytokeratins, neurofilaments, betaIII-tubulin, epithelial membrane antigen and neuron-specific enolase. Our results indicate that keratin and epithelial membrane antigen are reliable epithelial markers for SCLC. In addition, the positive staining with monoclonal antibodies TU-20 against betaIII-tubulin and neuron-specific enolase was found in some cases of SCLC. We suggest, that these antibodies could be a useful tool for complex immunohistochemical diagnosis of SCLC.