Both chemotherapy and radiation therapy are treatments used to combat cancer, a disease where cells grow uncontrollably and invade surrounding tissues. While chemotherapy involves administering medication to kill cancer cells throughout the body, radiation therapy specifically targets the affected area. Additionally, chemotherapy is considered a systemic treatment while radiation therapy can be localized or systemic. These treatments may cause side effects, but there is evidence that combining them with other treatments can have a significant impact on cancer. Both surgery and radiation are effective treatments for localized prostate cancer, and they work in different ways to shrink tumors and prevent the spread of cancer.