Augmentation Of Therapy For Favorable-Histology Wilms Tumor With Combined Loss Of Heterozygosity Of Chromosomes 1p And 16q: A Report From The Children'S Oncology Group Studies Aren0532 And Aren0533.

10009 Background: In National Wilms Tumor Study-5, tumor-specific combined loss of heterozygosity (LOH) of chromosomes 1p and 16q was associated with adverse outcome in patients with favorable histology Wilms Tumor (FHWT): stage I/II patients treated with Regimen EE4A (vincristine (VCR)/dactinomycin (DACT)) had 4-year EFS of 91.2% without LOH and 74.9% with LOH; stage III/IV patients treated with Regimen DD4A (VCR/ DACT/doxorubicin(DOX)) and radiotherapy (RT) had 4-year EFS of 83% without LOH and 65.9% with LOH. The AREN0533/AREN0532 studies assessed whether augmenting therapy would improve EFS for FHWT with combined 1p/16q LOH. Stage I/II patients were treated with the addition of DOX (Regimen DD4A) but no RT. Stage III/IV patients were treated with Regimen M (VCR/DACT/DOX alternating with cyclophosphamide/etoposide) and RT. Methods: Patients were enrolled through the AREN03B2 Biology and Classification study between10/2006 and 7/2013. All patients underwent central review of pathology, surgical reports ...