NCCN Guidelines for Patients
Breast Cancer – Locally Advanced (STAGE III)
Not all breast cancer cells are alike. They can differ
by the type of receptors they have. A receptor is
a protein found inside or on the surface of cells.
Substances bind to the receptors and cause changes
within the cell. The two types of receptor tests
important for treatment planning are described next.
Hormone receptor test
Estrogen and progesterone are hormones that are
present in all women. Among some women with
breast cancer, the cancer cells have receptors
to which these hormones attach. As shown in
, hormone receptors are inside of cells.
After hormones attach, the receptors enter the
nucleus and cause cells to grow in number. However,
the growth of cancer cells with hormone receptors
is usually slower than cancer cells without these
Testing for hormone receptors is important. There
are drugs that can be used to stop hormones from
causing cancer growth. IHC (
is the lab test used by pathologists for hormone
IHC involves applying a stain to cells then looking
at them with a microscope. The stain shows how
many cells have hormone receptors and the amount
of hormone receptors in the cells. If at least 1 out of
Key receptors in breast cancer
Hormone and HER2 receptors help breast cancer grow. Some women have a high amount of one
or both types of receptors. It is important to test for these cell receptors so that the best cancer
treatment is received.
Copyright © 2017 National Comprehensive Cancer Network
Cancer lab tests