Your medical oncologist or surgical oncologist may recommend one of three different forms of chemotherapy. Neo-adjuvant or primary systemic chemotherapy is used before radiation or surgery to help shrink the tumor. Adjuvant chemotherapy is used after radiation or surgery to destroy any remaining cancer cells. Systemic chemotherapy circulates throughout the body via the bloodstream when the cancer is metastatic.
Radiation therapy, which uses high-energy x-rays to shrink and destroy tumors cells, is used in the treatment of both colon and rectal cancers. If you have colon cancer, radiation therapy may be used after surgery to destroy any remaining cancerous cells that may be left behind. In cases of rectal cancer, radiation therapy is typically administered before or after surgery and often in combination with chemotherapy.