Shorter Radiotherapy Matches Standard Care for Breast Cancer
A Phase III trial found a 16-fraction radiotherapy schedule was noninferior to the conventional 25-fraction regimen after mastectomy.
Updated on Nov. 3, 2026 in Cancer
A Phase III randomized trial from Fudan University Shanghai Cancer Center found hypofractionated postmastectomy radiotherapy was noninferior to conventional radiotherapy for locoregional control. The findings were published in the Journal of Clinical Oncology on November 3, 2026.
Why it matters
A shorter treatment course could reduce the number of hospital visits patients need after mastectomy without compromising control of locoregional disease. The results add evidence to the case for fewer-fraction schedules in breast cancer care.
The trial randomized 1,494 patients and analyzed 1,429 in the modified intention-to-treat population, with a 5-year locoregional recurrence rate of 1.7% for the shorter schedule versus 2.2% for the conventional schedule. Grade 3 acute skin toxicity occurred in 1.7% of hypofractionated patients compared with 12.2% of conventional patients, and survival beyond the 58.1-month median follow-up has not been reported.
The players
Fudan University Shanghai Cancer Center
A leading oncology research and treatment institution in Shanghai, China, which led the HypoMast-IMNI trial.
The details
The hypofractionated arm delivered 42.56 Gy in 16 fractions, while the conventional arm delivered 50 Gy in 25 fractions, with both regimens targeting the chest wall and regional lymph nodes, including the internal mammary nodes. Radiation pneumonitis of grade 2 or higher occurred in 2.0% of patients on the shorter schedule versus 2.1% on the conventional schedule.
Timeline
Patients were randomized between September 2018 and July 2022.
The findings were published in the Journal of Clinical Oncology on November 3, 2026.
Big Picture
The trial tests whether the 16-fraction hypofractionated schedule can replace the long-established 50 Gy in 25 fraction postmastectomy standard without sacrificing locoregional control. Its results extend a line of hypofractionation research in breast cancer radiotherapy by focusing on regional nodal coverage, including the internal mammary nodes.
For patients facing mastectomy, a 16-fraction schedule may mean fewer radiation sessions than the conventional 25-fraction course, with grade 3 skin toxicity reported at 1.7% versus 12.2%. Patients should discuss fractionation options with their radiation oncology team to weigh recurrence outcomes against side-effect profiles.
The takeaway
Fewer radiation sessions can deliver comparable locoregional control with markedly less acute skin toxicity, giving patients and clinicians a stronger evidence base when choosing a postmastectomy schedule.
Further reading
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