Does the Cancer Have Genes that are Not Normal?

HER-2 status

(also called HER-2/neu)

HER-2 is a gene that helps control how cells grow, divide, and repair themselves. About one out of four breast cancers has too many copies of the HER-2 gene. The HER-2 gene directs the production of special proteins, called HER-2 receptors, in cancer cells. Read recent research about treatments for women with early-stage cancers that are HER2-positive.

Cancers with too many copies of the HER-2 gene or too many HER-2 receptors tend to grow fast. They are also associated with an increased risk of spread. But they do respond very well to treatment that works against HER-2. This treatment is called anti-HER-2 antibody therapy.

There are two tests for HER-2:

1. IHC test (IHC stands for ImmunoHistoChemistry)
   • The IHC test shows if there is too much HER-2 receptor protein in the cancer cells.
   • The results of the IHC test can be 0 (negative), 1+ (negative), 2+ (borderline), or 3+ (positive).
2. FISH test (FISH stands for Fluorescence In Situ Hybridization)
   • The FISH test shows if there are too many copies of the HER-2 gene in the cancer cells.
   • The results of the FISH test can be "positive" (extra copies) or "negative" (normal number of copies).

Find out which test for HER-2 you had. This is important. Only cancers that test IHC "3+" or FISH "positive" will respond well to therapy that works against HER-2. An IHC 2+ test result is called borderline. If you have a 2+ result, you can and should ask to have the tissue tested with the FISH test.