Er/pr & C Erb B2/her 2 Neu

Other names: Human epidermal growth factor receptor 2, ERBB2 amplification, HER2 overexpression, HER2/neu tests

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

Breast cancer

A cancer that starts in breast tissue is known as “Breast Cancer”.  It happens when breast tissue grows out of control and usually forms a tumour.

Like all the cancer, this may remain situated in breast tissue only or it may spread. Although much more common in women, it can be seen rarely in men too. There are various types of breast cancer involving different parts of inner and outer breast tissue. Eg. Breast skin, area around nipple or internal ducts etc.

Certain factor put you at higher risk of developing breast cancer

• Older age
• History of breast cancer or benign (non-cancer) breast disease
• Inherited risk of breast cancer, including having BRCA1 and BRCA2 gene changes
• Dense breast tissue
• Menstruatingat an early age
• Starting menopauseat a later age
• Taking hormone therapyfor symptoms of menopause
• Radiation therapyto the breast or chest
• Obesity
• Drinking alcohol

HER 2/ NEU

HER2 stands for human epidermal growth factor receptor 2. This is involved in normal cell growth. HER2/neu may be made in larger than normal amounts by some types of cancer cells, including breast, ovarian, bladder, pancreatic and stomach cancers. This causes cancer cells to grow and spread more quickly. HER2 amount plays critical role in deciding treatment plan.

• A new lump or thickening in or near the breast or in the armpit
• A change in the size or shape of the breast
• A dimple or puckering in the skin of the breast
• A nipple turned inward into the breast. Scaly, red or swollen skin in the nipple area
• Nipple discharge other than breast milk. The discharge might happen suddenly, be bloody or happen in only one breast.
• Pain in any area of the breast

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.

Your doctor will ask you to do this test, if you have

• Diagnosed with breast cancer, to find out if cancer HER positive, HER negative. Finding receptors on tumor cells will help tailor the treatment.
• To monitor ongoing treatment, if you have already been diagnosed with HER2 positive cancer.
• To check for relapse of cancer. i.e. if cancer has come back after 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:

HER2 positive refers to cancer cells which are expressing high levels of HER2 protein, this is indication of cancer which will progress faster and spread faster. This is very crucial in deciding the treatment regime and more rigorous monitoring. If you are being treated for HER2-positive cancer, normal results may mean you are responding to treatment. Results that show higher than normal amounts may mean your treatment is not working or that cancer has come back after treatment. If your results show normal amounts of HER2 protein or the normal number HER2 genes, you probably have HER2-negative cancer. You are advised to discuss your results with your doctor who will be able to explain the meaning of test results in your case.