# COG AREN0532

Source: https://onco.cc/trials/aren0532/  
OnCo record `aren0532` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

AREN0532 tested treating the lowest-risk Wilms tumours with surgery alone and no chemotherapy, and giving more treatment only to children whose tumours carried particular chromosome losses; both ideas worked and now guide how much therapy each child gets.

## Summary

AREN0532 was the Children's Oncology Group's risk-stratified trial for favourable-histology Wilms tumour, enrolling 808 children. Those under two years with small stage I tumours (very low risk) had nephrectomy alone and were watched; the standard-risk groups received vincristine and dactinomycin, with doxorubicin and radiotherapy added by stage, and those whose tumours showed loss of heterozygosity at both 1p and 16q, a marker of relapse identified in NWTS-5, were moved to more intensive regimens.

Surgery alone gave excellent survival in the very low-risk group, with the few relapses salvaged, and augmenting therapy for the 1p/16q loss group improved event-free survival compared with historical controls. The trial embedded molecular risk markers in Wilms tumour treatment for the first time.

## Fields

- Kind: Trial
- Status: completed
- Last checked: 2026-09-17
- Also known as: AREN0532
- Tags: subtype-trials
- Registry id: NCT00352534
- Phase: 3
- Setting: Very low-risk and standard-risk favourable-histology Wilms tumour: nephrectomy alone with observation for very low-risk disease, and risk-adapted vincristine, dactinomycin and doxorubicin with or without radiotherapy for the rest, with treatment intensified for tumours with loss of heterozygosity at 1p and 16q
- Sponsor: Children's Oncology Group
- Enrolled: 808
- Result: Nephrectomy alone was adequate for very low-risk favourable-histology Wilms tumour, and intensified therapy improved outcomes for tumours with 1p and 16q loss of heterozygosity.

## Sources

- ClinicalTrials.gov NCT00352534: https://clinicaltrials.gov/study/NCT00352534

## Connected records

- cancers: [Childhood cancers (all types)](https://onco.cc/cancers/childhood-cancers/), [Wilms tumour (nephroblastoma)](https://onco.cc/cancers/wilms-tumor/)
- drugs: [Dactinomycin (actinomycin D)](https://onco.cc/drugs/dactinomycin/), [Doxorubicin](https://onco.cc/drugs/doxorubicin/), [Vincristine](https://onco.cc/drugs/vincristine/)

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