The cortisol-type steroids prescribed for cancer treatment are different from anabolic steroids but the reasons for taking them are numerous. They help to reduce nausea that comes along with chemotherapy and radiation. This drug can also kill cancer cells and shrink tumors as part of the treatment. It also decreases swelling and it can reduce the allergic reactions. It often relieves the headaches that are cause by brain tumors. Doctors also will recommend steroids to help you sleep, eat, and feel better. Doctors can prescribe steroids for cancer treatment by injection, through an intravenous (IV) drip, in liquid or pill form or as a cream.