Her 2-Neu / Ki67 (Staining)

Specimen Required

SLIDES & BLOCKS

Fasting Required

Purpose of the Test

To determine whether a cancer, usually a breast cancer, is positive for HER-2 gene amplification or protein expression, which helps to guide treatment and determine outcome. HER-2 evaluation is also used in the assessment of some other cancer types including gastric and oesophageal cancer.

When this test is required

HER-2 testing is recommended as part of an initial workup of invasive breast cancer. It is sometimes done with recurrent or metastatic breast cancer, or in some other cancers. It helps the doctor determine treatment options and understand more about the cancer’s characteristics.

What the Test Detects

HER-2 is an oncogene present in the nucleus of all cells. It codes for a cell surface receptor of a chemical growth factor. When the growth factor binds to the receptor it becomes activated and this causes the cell to grow. Normal epithelial cells contain two copies of the HER-2 gene and produce low levels of the HER-2 protein. In about 20-30% of invasive breast cancers (and some other cancers, such as gastric, oesophageal, …HER-2 is an oncogene present in the nucleus of all cells. It codes for a cell surface receptor of a chemical growth factor. When the growth factor binds to the receptor it becomes activated and this causes the cell to grow. Normal epithelial cells contain two copies of the HER-2 gene and produce low levels of the HER-2 protein. In about 20-30% of invasive breast cancers (and some other cancers, such as gastric, oesophageal, ovarian and bladder cancer), the HER-2 gene has additional copies produced (gene amplification) and an abnormally large amount of the protein is produced (protein over-expression). Cancers which have this over-expression tend to grow more rapidly and do not respond as well to hormonal therapy and some chemotherapy, so these patients often have a poorer outcome. There are two main ways to test HER-2 status in cancer tissue: immunohistochemistry (IHC) and in situ hybridization undertaken either using a fluorescent or chromogen method (FISH or CISH). IHC measures the amount of HER-2 protein present. FISH and CISH look at the level for HER-2 gene amplification (the number of copies of the gene present). IHC is currently the most widely used initial testing method. If the ICH result is not clear, then the FISH or CISH method is often done as a follow-up test. See MoreSee Less

Preparation for the Test

No test preparation is needed.

Sample Requirements

A sample of cancer tissue obtained during a biopsy. Usually this test is done on the biopsy taken for initial diagnosis and a second biopsy is not needed. While HER-2 levels can be assessed in a blood sample, this is not usually done as treatment decisions rely on testing of the cancer cells in biopsy material.

Additional Notes

HER-2-positive tumours may be susceptible to trastuzumab (Herceptin), and other drug therapies created to target HER-2 protein. These drugs attach to the cancer cell surface and inhibit the growth of the cancer. The development of specialised therapies has increased the importance of HER-2 testing. Herceptin and other HER-2 targeted therapy may be used alone or with other chemotherapy agents. They are only useful in those who have a HER-2 positive cancer.HER-2 testing is not available in every pathology laboratory. IHC, FISH and CISH require experience and special training to perform and interpret. Your doctor may need to send your sample to a reference laboratory and the results may take over a week to return.

Selected Tests