NEW YORK – The National Comprehensive Cancer Network (NCCN) on Wednesday published its first set of treatment guidelines for nephroblastoma, a rare type of pediatric kidney cancer commonly known as Wilms tumor that accounts for roughly five percent of all childhood cancers.
Molecular testing to risk stratify patients is a key focus of the NCCN guidelines. Specifically, the NCCN recommends performing cytogenic and molecular testing at the point of diagnosis for all Wilms tumor patients with favorable histology, which comprises the majority of these cancers.
The testing, according to the guidelines, can identify unfavorable prognostic biomarkers such as chromosome 1q gain and/or loss of heterozygosity in chromosomes 1p and 16q. These biomarkers, along with factors such as patients' ages and clinical, radiographic, surgical, and pathological findings, play into determining their risk group, which the NCCN recommends using to guide therapy regimens, including choice of radiation or chemotherapy, dosing schedules, and decisions about appropriateness of surgical resection. There are no targeted therapies recommended in the Wilms tumor guidelines, though the NCCN encourages clinical trial participation for all cancer patients.
The guidelines also provide a detailed overview of all the congenital factors and somatic variants associated with Wilms tumor. WT1, a tumor suppressor gene found on chromosome 11p13, for instance, is known to play a role in normal kidney function, but when mutated, plays a role in the development of Wilms tumor. Somatic mutations in WT2, another tumor suppressor gene, plays a similar role.
Inherited mutations in several genes, such as REST, TRIM28, FBXW7, NYNRIN, KDM3B, XPO5, CHEK2, and PALB2, all play roles in Wilms tumor predisposition, NCCN notes in the guideline. Li Fraumeni syndrome, Perlman syndrome, Bohring-Optiz syndrome, and Mulibrey Nanism syndrome — all characterized by specific genetic anomalies — can also predispose someone to Wilms tumor. The guidelines recommend kidney ultrasounds every three months for up to eight years for those who have these predisposition syndromes.
Frank Balis of the Children's Hospital of Philadelphia, who chaired the Wilms tumor NCCN guidelines committee, said in a statement that the treatment approaches for Wilms tumor have been refined through clinical trials that have been conducted since the 1960s, but over time the treatment landscape has become more complex and nuanced. "The NCCN Guidelines for Wilms Tumor present clinicians with the latest evidence for the management of children with Wilms tumor based on their individual clinical and molecular profile," Balis said.