Prognostic significance of EPHB6, EFNB2 and EFNB3 expressions in neuroblastoma

Background. EPH family receptor tyrosine kinases and their ligand ephrins p lay pivotal roles in development. High-level expression of transcripts enco ding EPHB6 receptors (EPHB6), its ligands ephrin-B2 and ephrin-B3 (EFNB2, E FNB3) is predictive of favorable disease outcome of neuroblastoma (NB). Whe n combined with TrkA expression, the expression of EPHB6, EFNB2, or EFNB3 p redicts more accurately the disease outcome than each of the four variables alone. Procedure. Cox regression and Kaplan-Meier analyses were used to as sess the prognostic significance of EPHBG, EFNB2, EFNB3, and TrkA expressio ns in NB without MYCN amplification. Results. High-level expression of EFNB 3 or TrkA predicted favorable NBoutcome of NB without MYCN amplification (p < 0.03). As found in the general NB population, EPHB6, EFNB2, or EFNB3 exp ression in combination with TrkA expression was significantly predictive of the disease outcome of normal MYCN NB (p < 0.01). Conclusions. EPHB6, EFNB 2, and EFNB3 expressions may permit further refinement of the prognostic st ratification of NB into favorable and unfavorable groups. Med. Pediatr. Onc ol. 35:656-658, 2000. (C) 2000 Wiley-Liss, Inc.