Chemotherapy, or chemo, is considered a systemic treatment because the drugs travel throughout the body, killing cancer cells that have spread, or metastasized, to parts of the body far away from the original tumor.
Immunotherapy is treatment that uses a person's own immune system to fight cancer. It can boost or change how the immune system works so it can find and attack cancer cells.
Radiation therapy (also called radiotherapy) is a cancer treatment that uses high doses of radiation to kill cancer cells and shrink tumors.
Surgery is the oldest type of cancer treatment, and in many cases, still works well today to treat many types of cancer.