Prognostic significance of DNA di-tetraploidy in neuroblastoma

Background. Identification of biological factors may provide tools to discr iminate poor risk neuroblastoma patients of diagnosis, to uitimately offer risk adapted treatment intensity. Procedures. Tumour cell DNA content, MYCN amplification (NMA), deletion of the short arm of chromosome 1 (del 1p) as well as three serological markers were assessed in 179 children with neuro blastoma. Results. Localised regional disease (stage 1 to 3) was diagnosed in 98 patients, and disseminated disease in 81 patients (65 with stage 4, 1 6 with stage 4s). Median age at diagnosis was 12 months and the median obse rvation time 4 years. Sixty-seven of 179 patients had near di-tetraploid tu mours (37%), with a significantly worse prognosis of 44% overall survival a t 4 years in comparison with 88% in near triploid tumours (P < .001). The n ear di-tetraploid group showed a significant correlation with additional ad verse biological factors (NMA, del 1p: P < 0.001), age over 1 year (P < 0.0 01), clinical stage 4 (P < 0.001), elevated ferritin (P = 0.023), and eleva ted LDH (P < 0.001). Multivariate analysis based on the overall (OS) and ev ent free survival (EFS) estimations revealed that near di-tetraploidy was t he most powerful biological factor, with a P-value of < 0.001 for EFS and O S, followed by NMA (P = 0.015) for OS and del 1p (P = 0.047) for EFS. Concl usions. This analysis underlines the important influence of near di-tetrapl oidy on prognosis, and suggests that more efforts should be undertaken to i mplement this factor in future studies. Med. Pediatr. Oncol. 36. 83-92, 200 1. (C) 2001 Wiley-iiss, Inc.