Biomarkers to detect Wilms tumors in pediatric patients: where are we now?

Wilms tumor (WT) is the most common pediatric renal tumor. Survival rates are high, whether treated according to the European protocols (SIOP-RTSG) that use prenephrectomy chemotherapy or the Children's Oncology Group (COG) protocols, with immediate nephrectomy. However, the more intensive treatment given to higher risk subgroups may result in late effects. Current risk stratification does not identify all tumors that relapse and loss of heterozygosity of 16q and 1p are the only molecular biomarkers used in risk stratification. In this review we describe recent new genetic and epigenetic findings in WT and discuss their potential use as biomarkers. We discuss approaches to ensure representative sampling of WTs including the potential for 'liquid biopsy' to circumvent intratumoral heterogeneity.