NCIt definition : A doctor who specializes in treating cancer. Some oncologists specialize in a particular
type of cancer treatment. For example, a radiation oncologist specializes in treating
cancer with radiation.;
Alternative definition : NCI-GLOSS: A doctor who specializes in diagnosing and treating cancer using chemotherapy,
hormonal therapy, biological therapy, and targeted therapy. A medical oncologist often
is the main health care provider for someone who has cancer. A medical oncologist
also gives supportive care and may coordinate treatment given by other specialists.;