RecruitingPhase 2Drug trialLosartan to Reduce Radiation Induced Fibrosis in Breast Cancer PatientsThis study will evaluate the efficacy of losartan (LOS), an FDA-approved transforming growth factor beta-1 (TGF-β1) blocker, to decrease radiation induced fibrosis (RIF) in the breast and the lung of breast cancer patients, testing the hypothesis that Losartan will decrease RIF, TGF- β1 and cellular senescence/inflammation in the breast and the lung of irradiated breast cancer patients relative to placebo treatment and consequently improve clinical outcomes in breast cancer patients.