Medical Oncologists are experts in providing systemic, or whole-body, therapy to treat cancers. This can be done with a variety of drugs delivered either by infusion or orally. Most people diagnosed with breast cancer will meet a medical oncologist after surgery but in some cases, systemic treatment will come before surgery. This will be assessed by your surgeon and medical oncologist as a team. Your medical oncologist will monitor your health for several years or longer, after diagnosis and treatment.