Radiation May Not Be Needed for a Growing Number of Breast‑Cancer Patients, Study Finds

A recent clinical trial suggests that many women diagnosed with early‑stage breast cancer can safely skip postoperative radiation therapy, even when they belong to groups previously considered at higher risk of recurrence. The findings could reshape treatment guidelines and spare thousands of patients from the side‑effects and inconvenience of daily radiation sessions.The study, conducted by a consortium of leading oncology centers across North America and Europe, enrolled more than 1,200 women with hormone‑receptor‑positive, HER2‑negative tumors measuring up to 2 cm. All participants had undergone breast‑conserving surgery (lumpectomy) and were slated to receive standard whole‑breast irradiation. Researchers randomly assigned half of the cohort to forego radiation, while the other half received the conventional regimen of five weeks of daily treatment.After a median follow‑up of 6.5 years, the “no‑radiation” group experienced a local‑recurrence rate of 3.8 %, compared with 2.2 % in the radiation group—a difference that did not reach statistical significance. Importantly, overall survival and distant‑metastasis rates were virtually identical between the two arms. Sub‑analyses showed that women under 55, those with close or positive surgical margins, and patients with high‑grade tumors did not face an increased risk of recurrence when radiation was omitted, provided they received appropriate endocrine therapy.Dr. Elena Martínez, the trial’s principal investigator and a surgical oncologist at the University of Barcelona, explained, “Our data indicate that for many women—especially those whose tumors are biologically low‑risk and who are adherent to hormone therapy—the benefit of radiation is marginal. Eliminating it spares patients the fatigue, skin changes, and long‑term cardiac or pulmonary toxicity that can accompany radiation.”The research builds on a growing body of evidence that has already led clinicians to de‑intensify treatment for women deemed low‑risk. In the past decade, guidelines have recommended omitting radiation for patients over 70 with small, estrogen‑receptor‑positive cancers who plan to take tamoxifen. The new trial expands the potential pool of candidates to include younger women and those with modestly higher-risk features, as long as they meet strict pathological criteria.Patient advocates have welcomed the findings. “Radiation can be a major burden, especially for working mothers and those living far from treatment centers,” said Lisa Chang, director of the Breast Cancer Support Network. “If we can safely reduce or eliminate it for more women, that’s a win for quality of life without compromising cure rates.”Nevertheless, experts caution that the decision to skip radiation should remain individualized. Dr. Michael Patel, a radiation oncologist at Johns Hopkins Hospital who was not involved in the study, warned, “While the results are encouraging, radiation still offers a clear advantage for certain high‑risk subgroups—such as those with triple‑negative disease or extensive lymph‑node involvement. Shared decision‑making, guided by tumor biology and patient preferences, remains essential.”The study’s authors plan to continue monitoring participants for up to ten years to assess long‑term outcomes, including second‑cancer rates and late toxicities. If the durability of these results is confirmed, professional societies may soon revise their recommendations, potentially shifting the standard of care toward a more personalized, less invasive approach for a broader spectrum of breast‑cancer patients.