Oncology is the medical specialty dealing with the diagnosis and treatment of cancer. A specialist in the field is called an "oncologist".
The name of the speciality derives from the Greek word "Onkos" meaning "mass" or "tumor". In addition to diagnosis and treatment, an oncologist will also be involved with follow-up with treated patients, palliative care of terminal patients, the medical ethics of the treatment of patients, and the screening of asymptomatic individuals and those with a family history of cancer for early detection of the disease.
The medical history of the patient is the most important diagnostic tool as the chances of the descendant of an individual with cancer also having the disease is much higher than the occurrence of the disease in the general population. An oncologist must also know the most common symptoms of the disease and how to perform a differential diagnosis to rule out less serious conditions. The most common symptoms an oncologist looks for are fatigue, weight loss, anemia with no seeming underlying cause, fever in the absence of infection and paraneoplastic syndromes.
Treatment is generally with surgery if it is possible. Radiation therapy and chemotherapy are also commonly used together with surgery. More recently, hormone manipulation therapy has been used. Some experimental techniques involve the use of antibodies and vaccines.
There are several sub-specialities within oncology, including radiation oncology, surgical oncology, medical (chemotherapy) oncology, interventional radiation oncology, gynecological oncology and pediatric oncology.