Various chemotherapy treatments can target different cancers, and often multiple chemotherapy drugs are given together, which is called combination chemotherapy. Chemotherapy, sometimes called chemo for short, is a type of cancer treatment that involves using very strong drugs to damage and kill cancer cells. It is one of the three standard types of cancer treatment, along with surgery and radiotherapy. Chemotherapy drugs are used to treat many types of cancer. Learn why it's done, side effects and what to expect during chemotherapy treatment. Chemotherapy (often abbreviated chemo, sometimes CTX and CTx) is the type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) in a standard regimen.