DNA content and proliferative activity in children with neuroblastoma

Many studies have reported that neuroblastoma patients with aneuploid DNA c ontent and a low cellular proliferative activity have better outcome; other studies have reported contradictory results. Formalin-fixed, paraffin-embe dded archival pretreatment specimens of 56 neuroblastomas were studied. Thi ck sections from paraffin blocks were deparaffinized, and rehydrated. follo wing enzymatic digestion and filtration, cellular suspensions were analyzed by flow cytometry. Six tumors were aneuploid (13.3%) and 39 samples were d iploid (86.7%). S-phase fraction (SPF) ranged from 1 to 78% with a median o f 31 %. DNA ploidy and proliferative activity results showed no correlation with the prognostic variables. There was no significant difference between the 5-year overall and event-free survival rates of the aneuploid and the diploid neuroblastomas or between the neuroblastomas with a high and low pr oliferative activity. The results revealed the prognostic significance of n either DNA ploidy nor the cellular proliferative activity in neuroblastoma In contrast to other studies.