Results From AREN0533: Treating Higher-Risk Favorable-Histology Wilms Tumor
In a report from the Children’s Oncology Group AREN0533 study published in Journal of Clinical Oncology, Dix et al found improved survival outcomes with a modified approach to treatment of favorable-histology Wilms tumor with lung metastases.
Study Details
The National Wilms Tumor Study (NWTS) treatment of favorable-histology Wilms tumor with lung metastases was vincristine, dactinomycin, and doxorubicin (DD4A) and lung radiation therapy (RT). The AREN0533 study investigated a new strategy to improve event-free survival and reduce exposure to lung RT. Patients with complete lung nodule response (CR) after 6 weeks of DD4A continued receiving chemotherapy without lung RT; patients with incomplete response (IR) or loss of heterozygosity at chromosomes 1p/16q received lung RT and four cycles of cyclophosphamide/etoposide in addition to DD4A drugs (regimen M). AREN0533 was activated in February 2007 and closed to accrual in May 2013. The trial was designed to preserve a 4-year event-free survival rate of 85% for patients with lung nodule CR, and improve 4-year event-free survival from 75% to 85% for patients with lung nodule IR.
Event-Free and Overall Survival
Among 292 evaluable patients, 133 had CR and 159 had IR. Among patients with CR, 4-year event-free survival and 4-year overall survival were 79.5% and 96.1%. Expected (under null hypothesis of 85% event-free survival) vs observed event rates were 15% vs 20.2% (P = .052). Among patients with IR, 4-year event-free survival and 4-year overall survival were 88.5% and 95.4%. Expected vs observed event rates were 25% vs 12.2% (P < .001). Overall, 4-year event-free survival and 4-year overall survival were 85.4% and 95.6%, compared with 72.5% (P < .001) and 84.0% (P < .001) in the earlier NWTS-5 study.
The investigators concluded, “Excellent [overall survival] was achieved after omission of primary lung RT in patients with lung nodule CR, although there were more events than expected. [Event-free survival] was significantly improved, with excellent [overall survival], in patients with lung nodule IR using four cycles of cyclophosphamide/etoposide in addition to DD4A drugs. The overall AREN0533 treatment strategy yielded [event-free survival] and [overall survival] estimates that were superior to previous studies.”
The study was supported by National Cancer Institute grants and the St. Baldrick’s Foundation.
Jeffrey S. Dome, MD, PhD, from the Children’s National Health System, George Washington University School of Medicine and Health Sciences, is the corresponding author for the Journal of Clinical Oncology article.
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