# Wilms tumour risk markers (anaplasia, 1p/16q loss, 1q gain, SIOP and COG risk groups)

Source: https://onco.cc/terms/wilms-risk-markers/  
OnCo record `wilms-risk-markers` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Wilms tumour is cured in nine of ten children, so its markers exist to decide who needs less treatment and who needs more: anaplastic cells under the microscope, loss of chromosome pieces 1p and 16q or gain of 1q in the tumour DNA, and, in Europe, how much blastemal tumour survives the pre-operative chemotherapy.

## Summary

What is measured: the risk that a Wilms tumour will relapse. How: histology (favourable versus focal or diffuse anaplasia, the latter tied to TP53 mutation; in the SIOP system, which operates after four to six weeks of vincristine and actinomycin, the post-chemotherapy picture is graded low risk when completely necrotic, intermediate for regressive, epithelial, stromal, mixed and focal anaplastic types, and high risk for diffuse anaplasia and blastemal-type tumours), tumour DNA for loss of heterozygosity at 1p and 16q (in the COG system, loss of both in favourable-histology stages I to IV means augmented therapy), 1q gain (about 30 percent, adverse, now built into COG and SIOP UMBRELLA protocols), 11p15 loss of heterozygosity and TP53. Very low risk in COG is stage I favourable histology under age 2 with a tumour under 550 g, treated by nephrectomy alone. Germline testing (WT1, 11p15 imprinting disorders such as Beckwith-Wiedemann, DIS3L2) is offered when the tumour is bilateral, syndromic or in an infant, and bilateral disease is managed with nephron-sparing surgery. What a result changes: the intensity climbs from vincristine and actinomycin alone, through the addition of doxorubicin, to cyclophosphamide, carboplatin and etoposide with radiotherapy for anaplastic and other high-risk disease. Where it matters: Wilms tumour.

## Fields

- Kind: Term
- Last checked: 2026-09-17
- Also known as: anaplastic Wilms tumour; diffuse anaplasia; focal anaplasia; favourable histology Wilms tumour; unfavourable histology; 1p/16q loss of heterozygosity; LOH 1p and 16q; 1q gain in Wilms tumour; blastemal-type Wilms tumour; SIOP risk group; SIOP UMBRELLA; COG renal tumour risk group; very low risk Wilms tumour; bilateral Wilms tumour; nephrogenic rests; 11p15 loss of heterozygosity

## Connected records

- terms: [Cytogenetics and karyotype](https://onco.cc/terms/cytogenetics/), [Hereditary cancer syndromes](https://onco.cc/terms/hereditary-cancer-syndromes/), [TP53-mutated (p53-abnormal)](https://onco.cc/terms/tp53-mutated/)
- drugs: [Dactinomycin (actinomycin D)](https://onco.cc/drugs/dactinomycin/), [Doxorubicin](https://onco.cc/drugs/doxorubicin/), [Vincristine](https://onco.cc/drugs/vincristine/)
- technologies: [Germline (hereditary) testing](https://onco.cc/technologies/germline-testing/)
- cancers: [Wilms tumour (nephroblastoma)](https://onco.cc/cancers/wilms-tumor/)

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