Radiation Therapy and Capecitabine With or Without Curcumin Before Surgery in Treating Patients With Rectal Cancer

This randomized phase II trial studies how well radiation therapy and capecitabine with or without curcumin before surgery works in treating patients with rectal cancer. Drugs such as curcumin may make tumor cells more sensitive to radiation therapy. Drugs used in chemotherapy, such as capecitabine, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Giving chemotherapy with radiation therapy before surgery may make the tumor smaller and reduce the amount of normal tissue that needs to be removed. It is not yet known whether chemotherapy and radiation therapy is more effective with or without curcumin when given before surgery in patients with rectal cancer.