# NCIC MA.20

Source: https://onco.cc/trials/ma-20/  
OnCo record `ma-20` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

MA.20, published alongside EORTC 22922, showed that adding nodal irradiation after lumpectomy improves disease-free survival, mainly by preventing distant spread, without a survival difference at ten years.

## Summary

MA.20 randomised 1,832 women with node-positive or high-risk node-negative breast cancer treated by breast-conserving surgery and systemic therapy to whole-breast irradiation with or without regional nodal irradiation. Ten-year disease-free survival was 82.0 percent with nodal irradiation and 77.0 percent without (hazard ratio 0.76); overall survival did not differ (82.8 versus 81.8 percent), and lymphoedema and pneumonitis were more frequent (Whelan and colleagues, New England Journal of Medicine 2015).

## Fields

- Kind: Trial
- Status: positive
- Last checked: 2026-09-17
- Tags: radiation-wave4
- Registry id: NCT00005957
- Phase: 3
- Setting: Node-positive or high-risk node-negative breast cancer after breast-conserving surgery: whole-breast irradiation with or without regional nodal irradiation
- Sponsor: Canadian Cancer Trials Group
- Enrolled: 1832
- Result: 10-year disease-free survival 82.0% vs 77.0% (hazard ratio 0.76); overall survival unchanged.
- Outcomes: Disease-free survival at 10 years: Whole breast plus nodal irradiation 82% vs Whole-breast irradiation alone 77%

## Sources

- ClinicalTrials.gov NCT00005957: https://clinicaltrials.gov/study/NCT00005957
- NEJM 2015: https://doi.org/10.1056/NEJMoa1415340

## Connected records

- cancers: [HER2-positive breast cancer](https://onco.cc/cancers/breast-her2-positive/), [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/), [Triple-negative breast cancer (TNBC)](https://onco.cc/cancers/tnbc/)
- technologies: [IMRT / IGRT (modern external beam)](https://onco.cc/technologies/imrt-igrt/)
- terms: [Radiation pneumonitis and lung fibrosis](https://onco.cc/terms/radiation-pneumonitis/)

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