What Is an Oncologist?

An oncologist (ahn-KOL-eh-jist) is a doctor who diagnoses and treats different types of cancer.

What Is Oncology?

Oncology (ahn-KOL-eh-jee) is the medical specialty focused on the study, diagnosis, and treatment of cancer.

Why Would Someone Need an Oncologist?

Oncologists diagnose and treat cancer. They:

find out what stage a person's cancer is in (how much cancer is in the body and where it is)
prescribe cancer treatment, such as medicines, chemotherapy, radiation therapy, stem cell transplants, and surgery
give ongoing care for patients during and after cancer treatment

What Do Oncologists Do?

They do medical tests and procedures such as:

biopsies
bone marrow aspiration and biopsy
bone scan (used to find cancer or see how well treatment is working)
blood cell count tests
tumor marker tests (to look for substances made by cells in response to cancer)

Education and Training

An oncologist's training typically includes:

4 years of pre-medical education at a college or university
4 years of medical school — a medical degree (MD) or doctor of osteopathic medicine (DO) degree
3 years of residency (professional training in a hospital or clinic) in internal medicine or pediatrics
3 years of fellowship in oncology and hematology. A “fellow” is a doctor who had more specialty training after completing medical school and residency training.

They can also do special training in a subspecialty area — for example, a specific kind of cancer.

Surgical oncologists first become general surgeons in a 5-year residency and then complete a fellowship in surgical oncology and the removal of tumors.