Breast cancer is often treated with both surgery and radiation therapy. New research has suggested that the order of these treatments may impact patient outcomes. A study published by the Moffitt Cancer Center found that breast cancer patients who underwent radiation therapy prior to surgery were less likely to experience recurrence than those who underwent radiation after surgery. The findings applied to patients with estrogen-receptor positive cancers who had both partial and complete mastectomies. The results of similar studies have led some researchers to believe that pre-surgery radiation helps to teach the immune system how to fight cancer cells.