Shorter Radiotherapy Matches Standard After Mastectomy
Breast cancer patients given 16 sessions had similar recurrence control and far fewer severe skin reactions than the 25-session standard.
Updated on Nov. 3, 2026 in Cancer
A Phase III randomized trial found that a shorter, hypofractionated course of radiotherapy after mastectomy controls locoregional breast cancer recurrence about as well as the conventional longer course, with far less severe skin toxicity. The findings were published in the Journal of Clinical Oncology on November 3, 2026, and are relevant to women with breast cancer who are scheduled for chest-wall radiation after surgery.
Why it matters
Radiotherapy after mastectomy is often given over five or more weeks, and skin side effects are a common reason patients find treatment hard to complete. Showing that a 16-session schedule is noninferior gives oncologists stronger evidence for a more convenient option that may lower the burden of treatment.
This was a randomized noninferiority trial of 1,494 patients enrolled between September 2018 and July 2022, with 1,429 in the analysis population and a median follow-up of 58.1 months. Locoregional recurrence at 5 years was 1.7% with the hypofractionated schedule and 2.2% with the conventional schedule, and grade 3 acute skin toxicity was markedly lower with the shorter course.
The players
Journal of Clinical Oncology
A peer-reviewed oncology journal published by the American Society of Clinical Oncology that carries major clinical trial and treatment research in cancer care.
Fudan University Shanghai Cancer Center
A leading Chinese cancer hospital and research center affiliated with Fudan University that led the HypoMast-IMNI trial.
The details
The hypofractionated regimen delivered 42.56 Gy in 16 fractions, compared with 50 Gy in 25 fractions for the conventional regimen, so the total dose was delivered over fewer treatment sessions. Both arms targeted the chest wall and regional lymph nodes, including the internal mammary nodes, and the shorter schedule was not associated with a higher rate of severe lung inflammation, with grade 2 or higher radiation pneumonitis occurring in 2.0% versus 2.1% of patients.
Timeline
Patients were randomly assigned between September 2018 and July 2022.
Findings were published in the Journal of Clinical Oncology on November 3, 2026.
Health Landscape
Shorter radiotherapy schedules have gradually moved from early-stage breast cancer after lumpectomy into more complex treatment settings, and this trial tests that approach after mastectomy with regional nodal targeting. The result adds evidence that treatment intensity in breast cancer radiotherapy can potentially be reduced without sacrificing locoregional control.
If you are facing breast cancer surgery or recently had a mastectomy, a shorter radiotherapy schedule may be worth raising with your oncology team as an option to discuss. Ask how skin care and treatment side effects would be managed, since severe skin reactions were much less common with the shorter course in this trial.
The takeaway
Shorter radiotherapy after mastectomy controlled recurrence about as well as the longer standard course in this trial, with much less severe skin irritation. Bring questions about treatment schedule and side-effect tradeoffs to your oncologist when planning radiation.
Further reading
For more on how cancer treatments are tested and compared, explore our Cancer coverage.
