Oncology is a medical speciality that deals with prevention, diagnosis and treatment of all forms of cancer. This field is mastered over by a special type of doctor called an oncologist. There are different types of cancer that may affect different parts of the body. Therefore, an oncologist may decide to specialize in a certain branch, such as in breast cancer treatment, prostate cancer treatment or oral cancer.

An oncologist who specializes in surgical removal of cancer from a certain part of the body pursues the field called surgical oncology. For example, breast cancer surgery. An oncologist specializing in medical oncology relies on the use of anti-cancer drugs for the treatment of the patient. One such treatment is chemotherapy, in which high dose drugs are administered either intravenously or orally to kill cancer cells.

There is another field that involves the use of radiation therapy, which makes use of an high energy x-ray or proton particles to destroy the cancer cells from the site. Radiotherapy can be given externally with the help of a machine or internally with the help of radioactive seeds.