Association of high-level MRP1 expression with poor clinical outcome in a large prospective study of primary neuroblastoma.

Purpose: We have previously shown in a retrospective study that expression of the multidrug transporter gene MRP1 (ABCC1) is associated with outcome in neuroblastoma. We have now undertaken a prospective analysis to examine the independent prognostic significance of MRP1 expression in a large cohort of primary untreated neuroblastomas.

Patients And Methods: Two hundred nine diagnostic neuroblastoma samples from patients prospectively enrolled onto the Pediatric Oncology Group biology protocol 9047 were analyzed for expression of the MRP1, MDR1, MYCN, and TRKA genes using real-time polymerase chain reaction.