Oncologists monitor and patients diagnosed with cancer. When the patient is first referred an oncologist, the doctor runs a series of tests to confirm the presence of cancer and the stage of the disease’s development. The oncologist reviews all the symptoms and discusses treatment options, which may include chemotherapy, radiation therapy, surgery, or a combination of all three. Once the patient and the medical team decide on a course of action, the oncologist follows the patient’s progress, helping to alleviate symptoms and side effects, and changing treatment options when the current plan does not show measurable improvement.