Radiation therapy. Radiation can be performed after a tumor is surgically removed to catch stray cancer cells, before surgery to shrink a tumor, or as a stand-alone therapy.

There are two general kinds of radiation therapy: internal and external. Doctors usually recommend internal radiation, also called brachytherapy, when they want to target the cancer with a high dose of radiation delivered internally to a small area, such as tumors located in the breast, prostate, head, or neck. The radiation is implanted or injected in wires, "seeds," or capsules, then left in place for a period of time, either until they're removed or until they decay and become inactive. Brachytherapy is usually performed as an outpatient procedure, though sometimes doctors choose to implant a radioactive "source" at the end of surgery.

When the radiation is beamed into the body from an outside source, most often from an X-ray machine or linear accelerator, it's called external radiation. External radiation is usually given in the form of a sequence of treatments, typically five days a week for six to eight weeks. (On weekends, the patient gets a break so his body can recover.)

Radiation therapy is a rapidly improving technology, and there are many different types available.

Hormone therapy. Used most often to treat breast and prostate cancers, hormone therapy uses the body's own natural hormones to treat cancers that are affected by the hormones produced by the endocrine system. Because hormones fuel the growth of some types of cancer, cutting off or blocking the action of those hormones can stop the cancer from growing. Estrogen blockers, for example, can be very effective in treating some types of breast cancer, while blocking testosterone can be effective in preventing the growth of prostate cancer cells.