COMPARISON OF THE DIAGNOSTIC AND PROGNOSTIC VALUE OF BIOLOGICAL MARKERS IN NEUROBLASTOMA - PROPOSAL FOR A COMMON METHODOLOGY

Background: The prognosis of pediatric neuroblastoma depends both on c linical presentation and on certain cellular and molecular characteris tics. Screening programs have been initiated in infants of less than o ne year of age, based on the hypothesis that neuroblastoma progresses from early to late clinical stages through a classical multistep proce ss linked to an accumulation of molecular abnormalities. However, rece nt analyses suggest that most cases discovered by screening are low st age tumors considered as dysembryogenetic residues devoid from major a bnormalities and that high-grade tumors with molecular abnormalities a re unrelated diseases. Aim of the review: To confirm one or the other hypothesis, and eventually identify biological factors possibly respon sible for the initiation and progression of the disease, it is of upmo st importance that all investigators agree on biological criteria for analysis when neuroblastoma tissue is available in screened and unscre ened populations. This paper reviews the biological tools available fo r prognosis in neuroblastoma, the priority for analysis of biological markers according to both methodological reliability and feasibility, and the conditions of tissue storage for further analysis of these bio logical markers. Conclusion: The standardized biological evaluation of neuroblastoma will allow to collect sufficient data for multivariate analysis; such analysis is now fundamental if one wants to clearly def ine the respective impacts of biological abnormalities on neuroblastom a progression.