NEUROBLASTOMA - IMPACT OF BIOLOGICAL CHARACTERISTICS ON TREATMENT STRATEGIES

Neuroblastoma (NB) is the most frequent solid tumour in early childhoo d. NBs are extremely heterogeneous in terms of their biological charac teristics and the clinical behaviour which ranges from lethal disease to spontaneous regression and/or differentiation. Genetically, the het erogeneity of these rumours is reflected mainly by differences in the DNA content, presence of chromosome Ip deletions and amplification of the proto-oncogene N-myc. Up to now, only the prognostic impact of N-m yc amplification, based on a large series of analysed tumour samples, was established and is now used as the discriminating factor for treat ment stratification in a newly developed European protocol. The influe nce of other genetic aberrations, i.e. dellp36, t(1;17), ploidy and ex pression of certain proteins, such as nerve growth factor (NGF) recept or proteins and CD44, on the biological behaviour were studied only in a limited number of cases. We will review the literature and outline our own observations dealing with the peculiar phenomena observed in s ome NBs, i.e. spontaneous regression and/or maturation.