Oncology is a branch of medicine that deals with prevention, diagnosis and treatment of cancer. An oncologist is a physician, who treats cancer and provides medical care to a person diagnosed with cancer. Oncology is categorized in three main categories, namely, medical, surgical and radiation.

Medical oncologists are specialized in Medical Oncology field and Internal Medicine sub-branch. Medical Oncology specialists deal with pathological diagnosis of cancer patients diagnosed in other branches (General Surgery, Radiation Oncology, Pathology, Radiology), and side effects of oral or intravenous medicine therapy and chemotherapy. They also carry out post-treatment follow-up of patients.