A Phase 3 interventional study of Radiation and No Radiation in Breast Cancer, sponsored by Canadian Cancer Trials Group. Active, not recruiting at 485 sites in 2 countries. Open to female participants aged 35 Years and older. Per ClinicalTrials.gov, last updated 2026-07-01.
Sponsored by Canadian Cancer Trials Group · Phase 3, Interventional, and Treatment
The purpose of this study is to compare the effects on low risk breast cancer receiving usual care that includes regional radiation therapy, with receiving no regional radiation therapy. Researchers want to see if not giving this type of radiation treatment works as well at preventing breast cancer from coming back.
Women with node positive breast cancer normally will receive endocrine therapy and some may receive chemotherapy to help prevent the cancer from coming back. Many women will also receive radiotherapy to the whole breast/chest area and the surrounding lymph glands (called regional radiotherapy). No one really knows whether patients with low risk breast cancer need to receive regional radiotherapy. Some women may be getting regional radiotherapy who do not need it. These women may be exposed to the side effects of their treatment without benefit.
Exclusion Criteria:
A. Whole Breast Irradiation (WBI) following BCS or; B. No Radiotherapy (RT) following mastectomy
Radiation: Radiation · Other: No Radiation
A. WBI plus RT to the regional nodes (supraclavicular, non-dissected axillary, and internal mammary) following BCS or; B. RT to the chestwall and regional nodes (supraclavicular, non-dissected axillary, and internal mammary) following mastectomy
Radiation: Radiation
Radiotherapy given
No radiotherapy given
compare the breast cancer recurrence-free interval (BCRFI) between patients that received regional RT or not
Defined as time from randomization to time of invasive recurrent disease in the ipsilateral chestwall, breast, regional nodes, distant sites or death due to BC.
Time frame: 9.5 years
Compare the invasive disease-free survival between patients that received regional RT or not.
Defined as time from randomization to time of invasive recurrent disease in the ipsilateral chestwall, breast, regional nodes, distant sites or death due to BC
Time frame: 9.5 years
Compare the breast cancer mortality between patients that received regional RT or not.
Defined as death due to BC
Time frame: 9.5 years
Compare the overall survival (OS) between patients that received regional RT or not
Defined as the time from randomization to the time of death from any cause
Time frame: 9.5 years
Compare the locoregional recurrence-free interval (LRRFI) between patients that received regional RT or not.
Defined as time from randomization to time of invasive recurrent disease in the ipsilateral chestwall, breast or regional nodes, or death to due to BC
Time frame: 9.5 years
Compare the distant recurrence-free interval (DRFI) between patients that received regional RT or not.
Defined as time from randomization to time of invasive recurrent disease in distant sites or death due to BC
Time frame: 9.5 years
Number and severity of adverse events using the current CTCAE version 4
Time frame: 9.5 years
Compare arm volume and mobility measurements between patients that received regional RT or not
A Fisher's Exact Test will be used to compare lymphedema and arm abduction deficit between two arms. Defined as a difference in arm abduction of 10% or greater in the comparison of the ipsilateral to the contralateral arm.
Time frame: 9.5 years
Compare patient-reported outcomes (PROs) and the quality of life (QOL) between patients that received regional RT or not
using the NSABP Questionnaire for patients treated by BCS or mastectomy.
Time frame: 9.5 years
Compare the quality of life (QOL) between patients that received regional RT or not
Overall QOL (EORTC QLQ-C30) will be compared between the two treatment groups using a similar approach.
Time frame: 9.5 years
Compare the cost-effectiveness between patients that received regional RT or not
Costs will be expressed in $US and $CAN base currencies based on the final year of the study. An average cost per study subject by treatment arm for an overall mean cost per study arm will be generated
Time frame: 9.5 years
Compare the quality of life (QOL) between patients that received regional RT or not
breast symptoms (NSABP B32 Questionnaire) will be compared between the two treatment groups using a similar approach.
Time frame: 9.5 years
Compare the quality of life (QOL) between patients that received regional RT or not
skin symptoms and fatigue (EORTC QLQ-BR23) will be compared between the two treatment groups using a similar approach.
Time frame: 9.5 years
Showing the first 100 of 485 sites across 2 countries.
Plan to share: No
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This study is active, not recruiting, as verified in Jun 2026. You cannot join it, but the record below documents what was studied.
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Canadian Cancer Trials Group