The Postoperative Radiotherapy in N1 Breast Cancer Patients

This study is investigating whether postoperative radiation therapy benefits women with early breast cancer that has spread to a limited number of nearby lymph nodes (called pN1 — 1 to 3 positive nodes) after breast-conserving surgery or mastectomy. It aims to clarify whether radiation is necessary for all these patients or only some. **You may be eligible if:** - You are a woman aged 19 or older - You have had surgery (breast-conserving or mastectomy) for invasive breast cancer - After surgery, pathology showed 1 to 3 positive lymph nodes (pN1 stage) - You are receiving or planning to receive hormone therapy (if your cancer is hormone receptor-positive) - Your cancer type is appropriate for the study - You are in good overall health (ECOG 0–2) **You may NOT be eligible if:** - You had 4 or more positive lymph nodes after surgery - You have not agreed to participate or cannot provide consent - Your cancer characteristics fall outside the study criteria Talk to your doctor to see if this trial is right for you.