This page was reviewed under our medical and editorial policy by
Maurie Markman, MD, President, Medicine & Science
This page was updated on March 29, 2024.
According to data from the 2022 American Society of Clinical Oncology (ASCO) State of the Oncology Workforce in America, 13,365 physicians reported medical oncology or hematology/oncology as their primary practice in the United States—amounting to about six medical/hematology oncologists per 100,000 U.S. adults.
According to an ASCO practice survey published in 2018, the total number of oncology practices has been declining, but the size of existing practices has been increasing. The most recent ASCO survey shows many practices employ one to five oncologists, and 72 percent of practices have one location.
Medical oncologists treat cancer using certain cancer-fighting medications. Chemotherapy, given as a single drug or several drugs used together, is often used to treat, control and ease symptoms of cancer. Other drug treatments that may be recommended by medical oncologists include targeted therapy, hormone therapy and immunotherapy.
The number of patients who see a medical oncologist for chemotherapy as part of their cancer treatment varies based on the type of cancer and its stage. For example, according to the American Cancer Society, the percentage of people receiving chemotherapy for specific cancers is:
This overview will cover the basic facts about medical oncologists, including:
A medical oncologist is a highly trained physician who is an expert in treating cancer with medications like chemotherapy and more targeted approaches. As a member of the cancer treatment team, a medical oncologist helps determine the medication plan, depending on the cancer type, size and location. The medical oncologist also factors in the patient’s age, general health, other health conditions and previous cancer treatments when developing the treatment plan.
Whether medication is given intravenously (the most common delivery option for chemotherapy) or as a pill, the medical oncologist oversees treatment, monitors the patient’s progress and helps manage any side effects.
A medical oncologist also works closely with other members of the cancer care team, such as surgeons and radiation oncologists, to manage cancer care.
Medical oncologists, radiation oncologists and surgical oncologists have different roles in patient care:
A medical oncologist may consult with surgeons and radiation oncologists when other treatments in addition to medication are needed.
Medical oncologists are required to earn a bachelor’s degree, then a degree in internal medicine from a medical school, which takes four years to complete. Then they must complete a residency program, which may take from two to five years.
Medical oncologists also must take continuing education credits to maintain certifications.
Before beginning treatment, consider asking the medical oncologist these questions: