Serum polysialylated neural cell adhesion molecule in childhood neuroblastoma

Neuroblastoma cells express the polysialylated form of the neural cell adhesion molecule (NCAM), which normally becomes restricted to a few neural tissues after embryogenesis. In this study, we investigated serum levels of polysialylated NCAM in 14 children with different grades and stages of neuroblastoma using an immunoluminescence assay, and compared the results to 269 healthy control subjects. Simultaneously the polysialylated NCAM content of the tumours was determined by immunohistochemistry. Serum levels were dramatically elevated (more than sixfold) in children with advanced stages and fatal courses of disease, whereas children with differentiated tumour types and limited disease had low or normal levels. Serum concentrations correlated with the polysialylated NCAM content of the tumours, and they decreased during successful therapy. We therefore suggest polysialylated NCAM to be a useful marker monitoring childhood neuroblastoma.