FLOW CYTOMETRIC DNA CONTENT HELPS PREDICT ING RECURRENCE IN CHILDREN WITH NEUROBLASTOMA

Aim of the study was to evaluate the prognostic value of DNA index (DI ), S-phase fraction (SPF) and N-myc amplification in children with neu roblastoma, using fresh or frozen samples obtained at diagnosis. The s tudy includes 123 children with a mean age of 26 months followed-up fo r a mean time of 37 months to evaluate the overall survival (OS) and t he event-free survival (EFS). Death and recurrence incidences were res pectively 15% (18 cases) and 25% (30 cases). DNA aneuploidy (DI not eq ual I)incidence was 85/123 (69%) while median SPF was 6.1%. N-myc ampl ification was detected in 17/119 cases (14%) of which 15 corresponded to stage 4 tumors. Univariate analysis showed that OS probability was significantly correlated with stage (p = 0.0001), age (p = 0.0002), DI (p = 0.002) and, at lesser degree, with N-myc (p = 0.04). In particul ar, for the subgroup of children with stage 4, OS was only slightly in fluenced by DT (p = 0.02). Univariate probability EFS for the predicti on of recurrence (excluding stage 4s cases) was found to be high in ch ildren with tumours having DNA diploid (p = 0.001) and stage 4 (p = 0. 001). SPF values were not useful to predict neither OS nor EFS. Multiv ariate analysis was performed for both OS and EFS data: stage and age but not DI were relevant (p < 0.01) for predicting OS, while DI and st age but not age were relevant for predicting recurrence (EFS). In conc lusion, the present study indicates that flow cytometric DNA diploidy is an important prognostic factor of recurrence in children with neuro blastoma.