RecurIndex Guided Avoidance of Regional Nodal Irradiation for Node Positive Breast Cancer

This study is examining whether a genetic test called RecurIndex can help identify which breast cancer patients with limited lymph node involvement can safely skip radiation to the lymph node area (regional nodal irradiation), without increasing the risk of cancer returning. This could spare some women from unnecessary radiation side effects. **You may be eligible if...** - You are between 18 and 70 years old - You have invasive breast cancer confirmed after surgery - You have minimal lymph node involvement (micrometastasis or 1–3 lymph nodes affected) and meet specific low-risk criteria - Your cancer is hormone-receptor positive (estrogen receptor positive) - Your cancer is either HER2 negative or HER2 positive with estrogen receptor positive **You may NOT be eligible if...** - You have more extensive lymph node involvement - Your cancer is triple-negative (hormone receptor negative and HER2 negative) - You are over 70 years old or under 40 years old - You have extensive tumor blood vessel invasion Talk to your doctor to see if this trial is right for you.