Expression of neural cell adhesion molecules (polysialylated form of neural cell adhesion molecule and L1‐cell adhesion molecule) on resected small cell lung cancer specimens: In relation to proliferation state

BACKGROUND AND OBJECTIVES: Alteration of homotypic cell-cell adhesion has been suggested to play an important role in tumor progression. The present study examined the relationship between neural cell adhesion molecules and state of proliferation of small cell lung cancer (SCLC) cells. METHODS: Seventeen surgically resected specimens of SCLC were immunohistochemically examined, by using monoclonal antibodies against neural cell adhesion molecule (NCAM) and its polysialic acid side chains, and L1 cell adhesion molecule (L1-CAM). Ki-67 labeling indices were also determined immunohistochemically. RESULTS: All patients were positive for L1-CAM. Fifteen patients (88.2%) were positive for NCAM. Among the fifteen patients, nine (60.0%) were positive for NCAM PSA side chain. The probability of survival of the NCAM without PSA side chain group was significantly higher than that of the NCAM with PSA side chain group (log-rank test; P = 0.500). CONCLUSIONS: The expression of NCAM with PSA side chains might be a prognostic factor and NCAM a marker for SCLC. L1-CAM may be synthesized independent of state of proliferation of individual tumor cell and may affect clinical feature of SCLC.