Radiation OmisSion in PAtients With CLinically Node Negative Breast Cancer Undergoing Lumpectomy

This study (ROSACAL) investigates whether radiation therapy can be safely skipped after lumpectomy (breast-conserving surgery) in women with breast cancer who had a complete pathological response to chemotherapy given before surgery — meaning no cancer was detectable in the removed tissue or lymph nodes. **You may be eligible if...** - You are 50 years or older - You have node-negative breast cancer (no spread to lymph nodes at diagnosis) - You completed at least 8 weeks of chemotherapy before surgery, achieving a complete response (no remaining cancer in the breast or lymph nodes after surgery) - You had breast-conserving surgery with axillary staging - A clip was placed in your tumor bed before or during chemotherapy **You may NOT be eligible if...** - You are under 50 years of age - You have inflammatory breast cancer or cancer invading skin or chest wall - You have a BRCA1 or BRCA2 gene mutation - You have cancer in multiple areas of the same breast - You have had a previous breast cancer in the same or other breast Talk to your doctor to see if this trial is right for you.