Calculators & Tools

Wilms Tumour — Toronto / COG Stage

Nephroblastoma staging after upfront nephrectomy (COG convention).

1 What is the Wilms Tumour — Toronto / COG Stage?

The Wilms Tumour — Toronto / COG Stage is a oncology scoring tool used in paediatric practice. Nephroblastoma staging after upfront nephrectomy (COG convention). It scores 1 criteria and interprets the total across 5 bands, so the number always arrives with the severity it implies rather than on its own. In PediAid each criterion is shown as a labelled option with the weight it carries, so the total can be checked rather than taken on trust.

2 When to use it

  • Grading severity at the bedside in oncology
  • Recording an objective severity band in the case notes
  • Deciding when a total crosses the threshold for escalation
  • Re-scoring to track whether a child is improving or deteriorating
  • Checking the exact criteria of a score used infrequently

3 Formula & method

The score sums 1 criteria: Surgical and pathological extent. Totals are then banded: 1 stage or more - Stage I: stage I - excellent prognosis (>90% survival with favourable histology). Nephrectomy plus short chemotherapy; 2 stage or more - Stage II: stage II - completely resected beyond the kidney. Chemotherapy without flank radiotherapy in favourable histology; 3 stage or more - Stage III: stage III - residual abdominal disease. Chemotherapy PLUS flank/abdominal radiotherapy; 4 stage or more - Stage IV: stage IV - distant metastases. Intensified chemotherapy plus radiotherapy to metastatic sites as indicated; 5 stage or more - Stage V: stage V - bilateral disease. Nephron-sparing strategy with pre-operative chemotherapy; each kidney is also staged individually.
  • Histology (favourable vs anaplastic) is as important as stage for risk assignment.
  • Source: Gupta S, Aitken JF, Bartels U et al. Paediatric cancer stage in population-based cancer registries: the Toronto consensus principles and guidelines. Lancet Oncol 2016;17:e163-72.

4 Frequently asked questions

How many criteria does the Wilms Tumour — Toronto / COG Stage use?

1. They are Surgical and pathological extent.

What do the bands of the Wilms Tumour — Toronto / COG Stage mean?

The total is interpreted as: 1 stage or more - Stage I: stage I - excellent prognosis (>90% survival with favourable histology). Nephrectomy plus short chemotherapy; 2 stage or more - Stage II: stage II - completely resected beyond the kidney. Chemotherapy without flank radiotherapy in favourable histology; 3 stage or more - Stage III: stage III - residual abdominal disease. Chemotherapy PLUS flank/abdominal radiotherapy; 4 stage or more - Stage IV: stage IV - distant metastases. Intensified chemotherapy plus radiotherapy to metastatic sites as indicated; 5 stage or more - Stage V: stage V - bilateral disease. Nephron-sparing strategy with pre-operative chemotherapy; each kidney is also staged individually.

Does the score replace clinical judgement?

No. It is a structured way to record and communicate severity. A clinician concerned about a child should act on that concern regardless of the total.

Where does this score come from?

Histology (favourable vs anaplastic) is as important as stage for risk assignment.

Does it work offline?

Yes. Score definitions are bundled with the PediAid app, so the score computes without a connection.

For qualified clinicians. This page and the PediAid app are a clinical aid only. Calculations and reference data must be verified against the patient's clinical context, the source guideline and your local protocols before any treatment decision is made.