Combining losartan with radiotherapy increases tumor control and inhibits lung metastases from a HER2/neu-positive orthotopic breast cancer model.

Combining losartan with local irradiation significantly enhanced tumor response, at least in part via reduced tumor hypoxia presumably due to increased tumor perfusion. Our findings suggest that combining losartan with radiotherapy is a potential new treatment strategy for local control and inhibiting metastasis in HER2 + BC.