Pediatric renal tumors: practical updates for the pathologist.

Area of Science:

• Pediatric Oncology
• Nephrology
• Cancer Genomics

Background:

• The National Wilms Tumor Study Group achieved significant success in treating pediatric renal tumors over four decades.
• Recent advancements necessitate updated treatment protocols for pediatric kidney cancers.

Purpose of the Study:

• To summarize the new Children's Oncology Group (COG) renal tumor protocols.
• To highlight the pathologic requirements and changes in staging and eligibility criteria.

Main Methods:

• Registration on a central classification and banking protocol.
• Assignment to therapeutic protocols based on histology, stage, and molecular analysis.
• Centralized pathologic review and molecular testing of tumor samples.

Main Results:

• Updated staging criteria classify all tumor spillage as Stage III.
• Regional lymph node evaluation is now required for specific Stage I Wilms tumors and clear cell sarcoma.
• Modified chemotherapy regimens for favorable histology Wilms tumors with specific genetic markers (loss of heterozygosity for 1p and 16q).
• New protocols for bilateral Wilms tumors, diffuse hyperplastic perilobar nephroblastomatosis, anaplastic Wilms tumors, pediatric renal cell carcinoma, and extra-CNS rhabdoid tumors.

Conclusions:

• The new COG protocols represent a significant organizational and therapeutic shift in pediatric renal tumor management.
• Personalized therapy based on histology, stage, molecular findings, and treatment response is emphasized.
• Expanded eligibility includes previously untreatable rare renal tumors like pediatric renal cell carcinoma.