Children's Oncology Group/National Wilms' Tumor Study Group Staging System

**Semantic type:** Classification

**Definition:** A staging system for Wilms' Tumor that is based on the postoperative, pre-chemotherapy pathological features and findings relating to the extent of tumor spread.

**Synonyms:** - COG/NWTSG Staging System - Childrens Oncology Group/National Wilms Tumor Study Group Staging System