Overview
- The randomized SUPREMO study enrolled 1,607 women in 17 countries after mastectomy and axillary surgery, assigning 808 to chest-wall radiotherapy and 799 to no radiotherapy, with all receiving contemporary systemic therapy.
- Overall survival at 10 years was 81.4% with radiotherapy versus 81.9% without, with no improvement in disease-free survival or prevention of distant spread.
- Chest-wall recurrence was uncommon and slightly lower with radiotherapy, with 9 cases in the radiation group compared with 20 without treatment.
- Investigators conclude routine post-mastectomy radiation can be omitted for many intermediate-risk patients, while cautioning that higher-risk groups were not studied and may still benefit.
- Reported toxicity was mild with no excess cardiac deaths, and clinicians note that avoiding radiation can reduce treatment burden and lessen complications for breast reconstruction.