Gain of chromosome arm 17q predicts unfavourable outcome in neuroblastoma patients. U.K. Children's Cancer Study Group and the U.K. Cancer Cytogenetics Group.

Gain of chromosome arm 17q has recently been reported in neuroblastoma tumours. We analysed 17q status in relation to other known prognostic features and clinical outcome in a series of 45 tumours. Chromosome 17 status was detected by cytogenetic analysis, fluorescence in situ hybridisation (FISH) anc comparative genomic hybridisation (CGH) and correlated with other clinical and genetic factors. Survival analysis was calculated by the Kaplan-Meier estimation. Twenty-eight out of 45 tumours showed 17q gain, and this was associated with established indicators of poor prognosis; stage 4 disease (P < 0.001), age above 1 year at diagnosis (P < 0.001), 1p deletion (P < 0.01), MYCN amplification (P = 0.03) and diploidy/tetraploidy (P = 0.04). 17q gain was associated with poor outcome: 3-year survival was 13.5% compared with 100% for tumours without 17q gain (P = 0.0001); and progression-free survival (PFS) was 8.1% after 3 years compared with 83% for 17q normal tumours (P = 0.0001). PFS in 28 MYCN non-amplified patients indicated that 17q status has discriminatory power within this group: PFS 0% for 17q gain (n = 14) versus 100% for normal 17q (n = 14) (P = 0.0001). This study indicates that 17q changes have prognostic significance in neuroblastoma and should be a target for molecular cytogenetic detection at diagnosis.