Her 2/ Neu

Helps in prediction of response to Her2-directed therapy in patients with breast carcinoma or gastroesophageal adenocarcinoma.

Other names: Human epidermal growth factor receptor 2, ERBB2 test 

Invasive breast cancers are known to have more HER2/neu protein than normal. It is estimated that about 20% of breast cancer cases have higher number of these proteins on its cell surfaces.

The HER2/NEU test can give the doctor more information about your breast cancer. The test results will help the doctor tailor the treatment for you. HER2/NEU test is also used for monitoring cancer treatment and measuring the response to treatment.

Her-2/neu (ERBB2;c-erb-b2) proto oncogene is amplified in 15-20% of breast cancers. The gene is present on the long arm of chromosome 17 and predicts poor prognosis in invasive breast cancer. Accurate determination of Her-2/neu gene amplification becomes a crucial prerequisite as patients who are positive for gene amplification will be benefited and may improve the overall survival rate by the drug Herceptin (Trastuzumab). Fluorescence in situ hybrididization (FISH) and immunohistochemistry (IHC) are the two most common FDA approved methods to detect amplification and over expression for Her2. Her-2/neu FISH is mandatory to confirm the presence of Her2 amplification in cases with IHC 2+cases.

This test is ordered by the doctor after you have received a diagnosis of breast cancer. Finding receptors on tumor cells will help tailor the treatment. The doctor may also order more tests to find other receptors on cancer cells – example estrogen and progesterone receptor cells. If all of these receptors are present, then it is likely that you will respond well to the treatment.

Reporting criteria for Her2/Neu amplification by FISH (ASCO/CAP focused updated 2018 guidelines) as follows. Appropriate positive and negative controls are used with the test sample.

• Group 1 - HER2/CEP17 ratio of > 2.0 and the average HER2 copy number > 4.0 signals/cell (Positive)
• Group 2 - HER2/CEP17 ratio of > 2.0 and the average HER2 copy number < 4.0 signals/cell (Additional IHC workup needed)
• Group 3 - HER2/CEP17 ratio of < 2.0 and the average HER2 copy number > 6.0 signals/cell (Additional IHC workup needed)
• Group 4 - HER2/CEP17 ratio of < 2.0 and the average HER2 copy number > 4.0 and < 6.0 signals/cell (Additional IHC workup needed)

Group 5 - HER2/CEP17 ratio of < 2.0 and the average HER2 copy number < 4.0 signals/cell (Negative)

Interpretation:

Your doctor will help interpret the test result for you.