Neural cell adhesion molecule expression and clinical features in small cell lung cancer: a semi-quantitative immunohistochemical approach using an immunogold-silver staining method.

The neural cell adhesion molecule (NCAM) is a family of cell surface sialoglycoproteins mediating homotypic and heterotypic cell-cell adhesion. In tumors, NCAM is supposed to be involved with the malignant features characterized by invasive growth and metastasis. In the present study, we evaluated the correlation between NCAM expression of tumors obtained from small cell lung cancer (SCLC) patients and the clinical outcome. NCAM expression was determined semi-quantitatively by an immunogold-silver staining method using the SCLC cluster 1 monoclonal antibody NCC-LU-243. Of 20 SCLC patients studied, six patients with tumors with high NCAM expression had a poor response to chemotherapy, and a short disease-free (p = 0.011) and overall (p = 0.003) survival as compared with 14 patients having tumors with low NCAM expression. These findings indicate that the therapeutic outcome of SCLC may be partly predicted by determining the NCAM expression of the tumor.