The staging system used for Nephroblastoma / Wilms Tumour was developed by the National Wilms Tumor Study Group (NWTS) and updated by the Children’s Oncology Group Renal Tumor Committee.
Attend the tumour stages according to NWTS/COG system:
Stage I – The tumor is only in the kidney, and was removed completely by surgery; occur in about 40% of the cases.
Stage II – The cancer grew beyond the kidney (either into nearby fatty tissue or nearby blood vessels), but was completely removed surgically without any apparent cancer left behind; occur in about 20% of the cases.
Stage III – the tumour have not been completely removed or the tumour has spread to the lymph nodes in the abdomen; occur in about 20% of the cases.
Stage IV – the cancer has spread through the bloodstream to other organs far away from the kidneys, such as the lungs, liver, bone or to lymph nodes; occur in about 10% of the cases.
Stage V – when tumors are in both kidneys at the time of diagnosis; the treatment is based on the kidney with the more advanced stage after surgery; occur in about 5% of the cases.