Loss of Heterozygosity Analysis at Different Chromosome Regions in Wilms Tumor Confirms 1p Allelic Loss as a Marker of Worse Prognosis: A Study from the Italian Association of Pediatric Hematology and Oncology

Purpose: The specific aims of the AIEOP-TW-2003 protocol included prospectively investigating a possible association of tumor loss of heterozygosity with outcomes in children treated for Wilms tumor.Materials and Methods: We analyzed 125 unilateral favorable histology Wilms tumors registered between 2003 and 2008 in the Italian cooperative protocol for microsatellite markers mapped to chromosomes 1p, 7p, 11q, 16q and 22q.Results: The 3-year disease-free survival and overall survival probabilities were 0.87 (95% CI 0.81–0.93) and 0.98 (95% CI 0.96–1.0), respectively. Loss of heterozygosity at 1p was significantly associated with a worse disease-free survival (probability 0.67 for patients with and 0.92 for those without 1p loss of heterozygosity, p = 0.0009), as confirmed also by multivariate analysis adjusting for tumor stage and patient age at diagnosis. There was no difference in disease-free survival probability among children with loss of heterozygosity in the other chromosomal regions tested. The wor...