HER2 status also helps your doctor determine how aggressive the cancer is and treatment options. There are many differences between HER2 positive and HER2 negative breast cancers, from the biology of the tumors, to risk factors, aggressiveness, and much more. Understanding these differences is critical for anyone who has learned they have a positive HER2 status.
If you're struggling to find what you need, call our Support line on 7 days a week, 8am-8pm. HER2 human epidermal growth factor is a protein that can affect the growth of some breast cancer cells. If higher levels of it are found in a breast cancer, it is called HER2 positive breast cancer.
Some breast cancer cells have a higher than normal level of a protein called HER2 human epidermal growth factor receptor 2 on their surface, which stimulates them to grow. Around one in five invasive breast cancers breast cancer that has the potential to spread to other parts of the body are HER2 positive. All invasive breast cancers are tested for HER2 levels.
Genes contain the recipes for the various proteins a cell needs to stay healthy and function normally. Some genes and the proteins they make can influence how a breast cancer behaves and how it might respond to a specific treatment. Cancer cells from a tissue sample can be tested to see which genes are normal and abnormal. The proteins they make can also be tested.
Breast cancer is one of the most common cancers. Almost 25 percent of people newly diagnosed with cancer have breast cancer. One in 5 people with breast cancer have a type called HER2-positive.
As previously reported, the strategy does not worsen two-year overall survival but significantly shortens progression-free survival. The phase II trial randomly allocated patients to trastuzumab plus pertuzumab alone versus trastuzumab plus pertuzumab combined with chemotherapy until progression. After progression, both groups received T-DM1 as second line therapy.
The introduction of anti-HER2 therapies to the treatment of patients with HER2-positive breast cancer has led to dramatic improvements in survival in both early and advanced settings. Despite this breakthrough, nearly all patients with metastatic HER2-positive breast cancer eventually progress on anti-HER2 therapy due to de novo or acquired resistance. A better understanding not only of the underlying mechanisms of HER2 therapy resistance but of tumor heterogeneity as well as the host and tumor microenvironment is essential for the development of new strategies to further improve patient outcomes.
These targeted drugs are designed to block the growth and spread of cancer cells. These drugs work differently from chemotherapy drugs, which attack all cells that are growing quickly including cancer cells. Targeted drugs sometimes work even when chemo drugs do not. Some targeted drugs can help other types of treatment work better.
Which treatment is best for your HER2-positive breast cancer depends on several factors. The stage of the cancer whether it's early or metastatic plays a role in this decision, as does overall hormone receptor status; some people who are HER2-positive have tumors that are also estrogen-receptor positive triple-positive breast cancer. While your oncologist will consider all of this when choosing which HER2-positive treatment to recommend, it's also important to point out that receptor status can change from positive to negative, or vice versa.