HER2 Breast Cancer
What is HER2 Cancer?
HER2 (human epidermal growth factor receptor 2) is a protein and it promotes the growth of breast cancer cells. Cancerous cells with this protein tend to grow faster than other forms of breast cancer. It is occasionally called a ‘tumor marker’ and can be discovered in your blood or urine. While HER2 can’t be used for the diagnosis of cancer, it does provide crucial information. For instance, the presence of HER2 can aid doctors when it comes to predicting how breast cancer is likely to respond to different forms of treatment.
Facts & Figures
In 20 to 25% of cases, cancer cells make an excess of HER2 because of a gene mutation that only occurs in cancer cells and cannot be inherited from a parent. It is important for doctors to find out if the cancer cells in your body contain this protein, because it spreads particularly quickly. Younger women are more at risk of developing HER2 cancer. Women with HER2-positive cancer have a 77% five-year survival rate against the almost 94% five-year survival rate of women with HER2-negative cancer.
This form of cancer is less responsive to hormone treatment; however, there are effective targeted treatments specifically for HER2 cancer including:
- Trastuzumab (Herceptin): This drug targets HER2 to kill the cancer cells and reduce the chances of a recurrence. It can be used with chemotherapy and may also be used by itself or with hormone-blocking drugs, such as tamoxifen. It may have side effects, including allergic reaction and congestive heart failure.
- Lapatinib (Tykerb): This is another drug specifically for the treatment of HER2 and is often used on HER2-positive cancer that fails to respond to trastuzumab. It is often used with a chemotherapy drug known as capecitabine, though there are studies looking at how it works with trastuzumab. Typical side effects include loose stools and rashes; while there is also an increased risk of congestive heart failure.
Women should be routinely tested for HER2 if they have been diagnosed with invasive breast cancer because the results can impact decisions about treatment plans.