Q: How is radiation therapy used to fight breast cancer?

Radiation damages the DNA in cancer cells and inhibits their ability to reproduce. Normal cells, however, can usually recover from radiation damage more easily. Radiation therapy for breast cancer is most commonly used after a lumpectomy or mastectomy. The site where the tumor was removed often receives post-surgery radiation. Following surgery, radiation therapy may help prevent your cancer from recurring by treating any malignant cancer cells that may have been left behind or shed during surgery.