Among diagnosed women, approximately 30% have HER2-positive breast cancer.

What is HER2?

 HER2 refers to the human epidermal growth factor receptor 2. Varieties of growth factors are produced naturally by the body and, as with hormones, have an influence on how cells behave. HER2 is a receptor that is found on the surface of many cells and is involved in the cell’s response to the presence of certain growth factors.

In some breast cancer cells, there are an abnormally high number of HER2 receptors, which causes these cells to multiply more rapidly—these are known as HER2-positive cells.

In about one of every three breast cancers, the cancer cells make an excess of HER2 due to a gene mutation. This gene mutation can occur in many types of cancer — not only breast cancer.

What are the implications?

HER2 status has important implications for the prognosis and treatment of breast cancer. Being a distinct form of the disease, this condition requires special and immediate attention because HER2 tumors are fast growing. Early detection and testing is necessary to catch this different kind of breast cancer. HER2-positive breast cancers tend to be more aggressive than other types of breast cancer, and tend to grow more quickly. 

Treating HER2-positive breast cancer

They're also less responsive to hormone treatment. Knowing if a cancer is HER2-positive can sometimes affect the choice of treatment.

Many treatments are known to be either more or less effective depending on the HER2 status. For example, treatments containing anthracyclines are particularly effective in HER2- positive breast cancer, whereas tamoxifen is more effective in HER2-negative disease.

A targeted therapy called trastuzumab has been developed to be especially effective against HER2-positive breast cancer. It is a type of monoclonal antibody that specifically targets HER2, kills these cancer cells and decreases the risk of recurrence. Often used with chemotherapy, but may also be prescribed alone or in combination with hormone-blocking medications. Trastuzumab is the only anti-body-based therapy approved by health authorities to specifically target HER2-positive breast cancer. It functions by attaching to the HER2 on the surface of breast cancer cells and help prevent cell division and slow tumor growth. A study published in 2005 found that Trastuzumab can reduce breast cancer recurrence by as much as 50 percent. Trastuzumab is usually well tolerated.

Know more about HER2-positive Breast Cancer

You can ask your doctor about more information on HER2-positive breast cancer.

You can also learn more on breast cancer and HER2-positive breast cancer during a series of free breast cancer awareness lectures and screenings to be conducted by medical experts from the Philippine Society of Oncology, and the Philippine Society of Medical Oncology in cooperation with the C-Network, a cancer awareness advocacy campaign. During the lectures, free Breast Cancer Information kits will also be given to the participants. For more information, you can call the C-Network Secretariat at ExtantPR Systems 527-0478 or visit www.cnetwork.org.ph.