Methods: Frozen samples were analyzed by a rapid and well-standardised technique of immunostaining with monoclonal antibodies (MoAbs) against epitopes in the CD44 constant region.

Results: In this retrospective series, CD44 was expressed 102 specimens and strongly correlated with favorable tumor stages and histology, younger age, and normal N-myc copy numbers. In univariate analysis, CD44 expression and normal N-myc were the most powerful markers of favorable clinical outcome (P < 10(-6) and chi(2) = 65.40; and P < 10(-6) and chi(2) = 42.56, respectively), but analysis of CD44 affords significant prognostic discrimination in subgroups of patients with or without N-myc-amplified tumors. In the subgroup of stage IV neuroblastomas, CD44 was the only significant prognostic marker (P < .02, chi(2) = 5.76), whereas N-myc status was not discriminant. In multivariate analysis of five factors, ie, N-myc amplification, CD44 expression, age, tumor stage, and histology, the only independent prognostic factors of event-free survival were CD44 expression and tumor stage.

Conclusion: The analysis of CD44 cell-surface expression must be recommended as an additional biologic marker in the initial staging of the disease.