{"entity":{"id":"post-mastectomy-radiotherapy","kind":"term","name":"Radiotherapy after mastectomy","aka":["postmastectomy radiotherapy","PMRT","chest wall radiotherapy","chest-wall irradiation"],"tldr":"Radiotherapy to the chest wall, and often the nearby lymph node areas, after the breast has been removed. It clearly helps women with cancer in several lymph nodes. For women with one to three involved nodes treated with modern drugs, a trial that reported in 2025 found it did not lengthen life.","summary":"The classic evidence is the Early Breast Cancer Trialists' Collaborative Group overview of 8,135 women randomised in 22 trials between 1964 and 1986. Among 700 women with clear nodes after axillary dissection, radiotherapy did nothing to locoregional recurrence, overall recurrence (rate ratio 1.06, 0.76 to 1.48) or breast cancer mortality (1.18, 0.89 to 1.55). Among 1,314 women with one to three positive nodes it reduced locoregional recurrence, overall recurrence (rate ratio 0.68, 0.57 to 0.82) and breast cancer mortality (0.80, 0.67 to 0.95), and the same held in the 1,133 who received systemic therapy in both arms. Among 1,772 women with four or more positive nodes it reduced overall recurrence (0.79, 0.69 to 0.90) and breast cancer mortality (0.87, 0.77 to 0.99).\n\nThose trials predate anthracyclines, taxanes, aromatase inhibitors and trastuzumab, and the overview says so: for today's women the absolute gains might be smaller, although the proportional gains might be larger because the radiotherapy itself is better. SUPREMO was designed to settle it in the modern era, and reported in 2025. Among 1,607 patients with intermediate-risk disease, defined as pT1N1, pT2N1, pT3N0 or pT2N0 with grade 3 histology or lymphovascular invasion, ten-year overall survival was 81.4 percent with chest-wall irradiation and 81.9 percent without (hazard ratio 1.04, 0.82 to 1.30, p=0.80). Chest-wall recurrence was 1.1 against 2.5 percent (hazard ratio 0.45, 0.20 to 0.99), so the treatment worked and the disease it prevents is simply rare.\n\nSUPREMO tested chest-wall irradiation alone and not comprehensive nodal irradiation, so it does not answer the nodal question, and its accrual was long and its eligibility widened part way through. That is why commentary since has drawn opposite conclusions from the same paper.\n\nIn England NICE NG101 recommendation 1.13.10 offers postmastectomy radiotherapy to people with node-positive macrometastatic disease or involved margins, 1.13.11 considers it for node-negative T3 or T4 disease, and 1.13.12 says not to offer it to people at low risk of local recurrence, for example most people who are node-negative. Recommendations 1.13.26 to 1.13.29 carry the same logic across to patients treated with chemotherapy before surgery, and the guideline predates both SUPREMO and NSABP B-51.","asOf":"2026-09-25","links":[{"label":"EBCTCG: radiotherapy after mastectomy, 8,135 women in 22 trials (The Lancet 2014)","url":"https://doi.org/10.1016/S0140-6736(14)60488-8"},{"label":"SUPREMO ten-year survival (New England Journal of Medicine 2025)","url":"https://doi.org/10.1056/NEJMoa2412225"},{"label":"NICE NG101 recommendations 1.13.10 to 1.13.12, radiotherapy after mastectomy","url":"https://www.nice.org.uk/guidance/ng101"}],"tags":[],"related":["mastectomy","breast-reconstruction","hypofractionation","radiotherapy-omission-early-breast-cancer"],"cancers":["breast-cancer","breast-hr-positive","breast-her2-positive","tnbc"],"sections":["radiation"],"technologies":["imrt-igrt","hypofractionated-radiotherapy"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":["supremo","nsabp-b51","ma-20","eortc-22922","nsabp-b04"],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"category":"Treatment jargon"},"route":"/terms/post-mastectomy-radiotherapy/","neighbours":{"term":[{"id":"breast-reconstruction","kind":"term","name":"Breast reconstruction","route":"/terms/breast-reconstruction/"},{"id":"deep-inspiration-breath-hold","kind":"term","name":"Deep inspiration breath-hold (DIBH)","route":"/terms/deep-inspiration-breath-hold/"},{"id":"hypofractionation","kind":"term","name":"Hypofractionation (fewer, larger radiotherapy doses)","route":"/terms/hypofractionation/"},{"id":"radiotherapy-omission-early-breast-cancer","kind":"term","name":"Leaving radiotherapy out","route":"/terms/radiotherapy-omission-early-breast-cancer/"},{"id":"mastectomy","kind":"term","name":"Mastectomy","route":"/terms/mastectomy/"}],"cancer":[{"id":"breast-cancer","kind":"cancer","name":"Breast cancer (all types)","route":"/cancers/breast-cancer/"},{"id":"breast-her2-positive","kind":"cancer","name":"HER2-positive breast cancer","route":"/cancers/breast-her2-positive/"},{"id":"breast-hr-positive","kind":"cancer","name":"HR-positive / HER2-negative breast cancer","route":"/cancers/breast-hr-positive/"},{"id":"tnbc","kind":"cancer","name":"Triple-negative breast cancer (TNBC)","route":"/cancers/tnbc/"}],"section":[{"id":"radiation","kind":"section","name":"Radiation Therapy","route":"/fronts/radiation/"}],"technology":[{"id":"hypofractionated-radiotherapy","kind":"technology","name":"Hypofractionated radiotherapy","route":"/technologies/hypofractionated-radiotherapy/"},{"id":"imrt-igrt","kind":"technology","name":"IMRT / IGRT (modern external beam)","route":"/technologies/imrt-igrt/"}],"trial":[{"id":"eortc-22922","kind":"trial","name":"EORTC 22922/10925","route":"/trials/eortc-22922/"},{"id":"fast-forward","kind":"trial","name":"FAST-Forward","route":"/trials/fast-forward/"},{"id":"ma-20","kind":"trial","name":"NCIC MA.20","route":"/trials/ma-20/"},{"id":"nsabp-b04","kind":"trial","name":"NSABP B-04","route":"/trials/nsabp-b04/"},{"id":"nsabp-b51","kind":"trial","name":"NSABP B-51 / RTOG 1304","route":"/trials/nsabp-b51/"},{"id":"supremo","kind":"trial","name":"SUPREMO (BIG 2-04)","route":"/trials/supremo/"}]}}