Losartan to Reduce Radiation Induced Fibrosis in Breast Cancer Patients

This trial tests whether losartan — a commonly used blood pressure medication — can help prevent radiation-induced fibrosis (scarring of breast tissue) in breast cancer patients receiving radiotherapy after surgery. Reducing scarring could improve long-term cosmetic and functional outcomes. **You may be eligible if...** - You have been diagnosed with breast cancer (any stage, including DCIS) - You have had breast-conserving surgery or mastectomy with reconstruction - You are a candidate for radiation therapy after surgery - You are receiving treatment at a participating hospital **You may NOT be eligible if...** - You are not receiving radiation therapy - You have had bilateral (both-sided) breast surgery requiring radiation - You have specific contraindications to losartan (such as certain kidney or blood pressure conditions) Talk to your doctor to see if this trial is right for you.