- An oncologist is a doctor who specializes in treating people with cancer.
- The three main types of oncologists are medical, surgical, and radiation oncologists.
- These different types of oncologists often work together to treat a person with cancer.
Oncology is the study of cancer. A doctor who specializes in treating people with cancer is called an oncologist. Usually, an oncologist manages care and treatment once a person is diagnosed with cancer.
Within the field of oncology, there are three primary clinical disciplines: medical oncology, surgical oncology, and radiation oncology.
- A medical oncologist specializes in treating cancer with chemotherapy (the use of drugs to kill cancer cells, usually by stopping the cancer cells’ ability to grow and divide) or other medications, such as targeted therapy  and oral (in pill form) chemotherapy.
- A surgical oncologist specializes in the removal of the tumor and surrounding tissue during an operation. A surgical oncologist also performs biopsies (the removal of a small amount of tissue for examination under a microscope).
- A radiation oncologist specializes in treating cancer with radiation therapy (the use of high-energy x-rays or other particles to kill cancer cells).
The American Society of Clinical Oncology (ASCO) also recognizes other types of oncologists:
- A gynecologic oncologist focuses on the care and treatment of women with gynecologic cancers, such as uterine cancer and cervical cancer.
- A pediatric oncologist specializes in the treatment of children with cancer. This specialty includes all three primary oncology disciplines listed above. (Some types of cancer occur most often in children and teenagers, such as certain brain tumors, leukemia, osteosarcoma, and Ewing’s sarcoma. However, they occasionally occur in adults. In these instances, an adult may decide to be treated by a pediatric oncologist.)
- A hematologist-oncologist specializes in the diagnosis and treatment of cancers of the blood, such as leukemias, lymphomas, and myelomas.
The role of the oncologist
ASCO believes that an oncologist is responsible for the care of a patient from the moment of a cancer diagnosis throughout the course of the disease. The oncologist’s role includes the following:
- Explaining the cancer diagnosis and stage (a description of where the cancer is located, if or where it has spread, and whether it is affecting other parts of the body) to the patient
- Discussing all of the treatment options and recommending the best course of treatment
- Delivering high-quality, compassionate care
- Helping maintain the patient’s quality of life by managing cancer-related pain and other symptoms or treatment side effects, such as constipation, nausea and vomiting, and fatigue
A person with cancer is often treated by a multidisciplinary team of oncologists, meaning a group of doctors who specialize in different areas of oncology. This approach is used because cancer treatment frequently involves a combination of surgery, chemotherapy, and radiation therapy.
Other medical professionals involved in a patient’s care usually include the following:
- A pathologist (a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease)
- A diagnostic radiologist (a doctor who specializes in performing and interpreting imaging tests, such as x-rays or ultrasound tests, to diagnose disease)
- An oncology nurse 
- An oncology social worker 
The team may also include doctors who specialize in other areas of medicine. For example, a dermatologist (a doctor who specializes in skin problems) may help treat people with skin cancer. Learn more about the oncology team .
If a person’s cancer diagnosis is complex, the patient’s primary oncologist may ask a tumor board to review the case. A tumor board consists of medical experts from all relevant disciplines who consult on the best course of treatment.