SABER Study for Selected Early Stage Breast Cancer

This study is testing an intensive, shorter-course radiation treatment for older women with early-stage, hormone-receptor-positive breast cancer following surgery. The goal is to deliver effective treatment in fewer visits while closely monitoring cancer control and side effects. **You may be eligible if:** - You are a woman aged 50 or older - You have confirmed invasive breast cancer that is ER/PR-positive and HER2-negative (hormone-driven, not HER2-driven) - Your cancer is small (stage T1N0M0 — no lymph node involvement, no spread) - Your cancer is in one spot only (unifocal) - You have had genomic testing (Oncotype DX or MammaPrint) before starting treatment - You are in good general health and able to have MRI scans **You may NOT be eligible if:** - You have cancer in more than one location in the breast - Your cancer has spread to lymph nodes or other organs - You are HER2-positive or hormone-receptor-negative - You are under 50 years of age Talk to your doctor to see if this trial is right for you.