A new international study has found that many women with early-stage breast cancer who have a mastectomy and receive modern drug treatments may not need radiation therapy to the chest wall.
The study, published in The New England Journal of Medicine (November 2025), followed over 1,600 women with breast cancer that had spread to one to three lymph nodes or carried other moderate-risk features. All had undergone mastectomy, lymph node surgery, and modern systemic treatments such as chemotherapy, hormone therapy, or targeted therapy.
Half of the women received chest-wall radiation after surgery, and half did not. After 10 years of follow-up:
- Survival rates were nearly identical in both groups: about 81 percent of women were alive at 10 years, whether they received radiation or not.
- Cancer returning in the chest wall was slightly less common in the radiation group (1 percent) compared with the no-radiation group (2.5 percent).
- Rates of cancer spread or recurrence elsewhere in the body were similar between groups.
According to the researchers, chest-wall radiation did not improve overall survival for women in this intermediate-risk category. However, radiation did modestly reduce the small chance of cancer returning in the chest area.
These findings suggest that for many women with early-stage breast cancer who already receive effective drug treatments, radiation after mastectomy might not always be necessary. But treatment decisions remain highly individual. The researchers note that radiation may still benefit patients with a higher risk of recurrence, so treatment decisions should always be made in partnership with the oncology team. Each person’s cancer type, risk factors, and preferences should be discussed carefully with their oncology team.
Questions to Ask Your Oncologist About Radiation After Mastectomy
- Based on my specific breast cancer (type, stage, lymph node involvement, and other features), do I need chest wall radiation after my mastectomy?
- What are the benefits and risks of adding radiation for someone with my cancer profile?
- How does my number of affected lymph nodes impact the need for radiation?
- If I don’t have radiation, what is my risk of cancer coming back in the chest area?
- Will my other treatments (chemotherapy, hormone therapy, or targeted therapy) affect the benefits of radiation?
- What side effects should I expect if I have post-mastectomy radiation?
- Are there guidelines or studies—like the one published in The New England Journal of Medicine in 2025—that apply to my case?
- How might my age, health, or preferences influence the decision?
- Would radiation affect my breast reconstruction or healing?
- How does my risk of recurrence compare to other patients who may or may not need radiation?
- Can we review my pathology report together to see if radiation is recommended for me?
- Are there other ways to reduce my risk if I decide not to have radiation?
- How often would I need to be monitored if I skip radiation?
Reference
Kunkler IH, Russell NS, Anderson N, et al; SUPREMO Trial Investigators; Sunil. Ten-Year Survival after Postmastectomy Chest-Wall Irradiation in Breast Cancer. N Engl J Med. 2025 Nov 6;393(18):1771-1783. doi: 10.1056/NEJMoa2412225. PMID: 41191939.
