Hypofractionated versus conventional fractionated postmastectomy radiotherapy for patients with high-risk breast cancer (CHN HYPOPMRT): 10-year outcomes from a randomised, non-inferiority, open-label, phase 3 trial.

Hypofractionated postmastectomy radiotherapy is non-inferior to conventional radiotherapy in 10-year locoregional control for high-risk breast cancer patients, with similar safety profiles.

• Why it matters: Long-term evidence for hypofractionated radiotherapy after mastectomy with regional nodal irradiation is limited, making it unclear if it can replace standard treatment without compromising outcomes.
• What they did: A phase 3 randomized trial compared 15 fractions of hypofractionated radiotherapy to 25 fractions of conventional radiotherapy in 820 women with high-risk breast cancer, with a median follow-up of 11.5 years.
• The result: 10-year locoregional recurrence rates were 10.3% versus 12.0%, with no significant difference in severe adverse events, supporting hypofractionation as a safe, time-efficient alternative.