III. To prospectively analyze 1p, 11q, 14q and 17q allelic status, MYCN copy number by quantitative polymerase chain reaction (PCR); and the expression pattern of neurotrophin-related genes in diagnostic neuroblastoma tumors, and assay for the presence of rare tumor cells in biological specimens by reverse transcription (RT)-PCR; these biological variables will be analyzed for independent clinical significance compared to MYCN amplification, International Neuroblastoma Staging System (INSS) stage, age, ploidy, and histologic variables in predicting either response to treatment or outcome.