The use of high-energy rays to damage cancer cells, stopping them from growing and dividing. Like surgery, radiation therapy is a local treatment that affects cancer cells only in the treated area. See also external (beam) radiation therapy.

The treatment of disease with ionizing radiation. Also called radiation therapy.

In cell biology, a structure on the surface of a cell (or inside a cell) that selectively receives and binds a specific substance. There are many receptors. In breast cancer, the most commonly discussed receptors are for estrogen and progesterone. To take an example, the receptor for estrogen, a molecule that acts as a messenger for the proliferation of breast tissue, is a unique harbor on the cell surface where estrogen docks. Without this receptor, or if a medication (eg, tamoxifen) is taken which blocks this receptor, estrogen cannot dock and cannot deliver its instructions to proliferate (go through cell division).

To occur again. To return. In breast cancer, after treatment has been completed, there is typically no sign of any cancer anywhere in the body. Even so, some women will later be found to have some of the same breast cancer growing again, either in the same area (local recurrence) or elsewhere (distant recurrence).

The return of a sign, symptom or disease after a remission. The reappearance of cancer cells at the same site or in another location is, unfortunately, a familiar form of recurrence.

Back again. A recurrent fever is a fever that has returned after an intermission: a recrudescent fever.