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HER2-positive Breast Cancer Central

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    Quick and informative HER2-positive breast cancer facts

    • As a result of the COVID-19 vaccine injection, the lymph nodes under the arm may swell. Swollen lymph nodes under the arm might show up on a mammogram during breast cancer screenings, which could cause concern and lead to further tests. If the patient has a mammogram scheduled after receiving the COVID-19 vaccine, it is important to know when and in which arm the patient received the injection.
    • Patients with a history of breast cancer should avoid getting the vaccine injected into the arm on the side of the body affected by breast cancer. Patients who have a history of breast cancer in both breasts should ask their physician which arm should be injected. COVID-19 vaccines can be given in the upper hip area as an alternative, but providers at the vaccination site may not be trained in or comfortable with giving the vaccine this way.
    • The Society of Breast Imaging recommends that women should try to schedule their routine screening mammogram at least a month after receiving a COVID-19 vaccine so the swelling in the axillary lymph nodes has time to go away.
    • According to a 2021 study, patients with breast and gynecologic cancers tolerate the COVID-19 vaccines while undergoing systemic cancer therapy. The vaccines have an acceptable safety profile with self-limiting local and systemic adverse events.
    • Human epidermal growth factor receptor 2, or HER2, is a gene that creates HER2 proteins, also referred to as HER2/neu proteins, on breast cells to control healthy breast cell growth.
    • In about one of every five breast cancers, HER2 gene amplification occurs. The HER2 gene fails to work properly and generates too many copies of itself, causing cells to create an excess number of HER2 receptors and allowing breast cells to grow and divide uncontrollably. This is also known as HER2 protein overexpression.
    • HER2 status has a substantial impact on treatment, which is why experts recommend that all invasive breast cancers be tested for HER2. To determine HER2 status, biopsies or surgical samples are tested with immunohistochemical stains (IHC) or fluorescent in situ hybridization (FISH).
    • Many clinicians believe that the FISH test is more accurate than IHC, but FISH is more expensive, and the results take longer to come in. The cancer is determined to be HER2-negative if the IHC result is 0 or 1+, and HER2-positive if the IHC result is 3+. The HER2 status is unclear when the results of IHC is 2+ and retesting with FISH can provide clarity.
    • Breast cancers found to have HER2 gene amplification or HER2 protein overexpression are classified as HER2-positive. These cancers generally grow more quickly, and compared with HER2-negative breast cancers, HER2-positive breast cancers also tend to metastasize and recur.
    • Among patients whose breast cancer has recurred as an advanced disease, it can be beneficial to take additional biopsies to retest for HER2 status because some breast cancers that were initially HER2-positive can transform into HER2-negative disease, while others that were initially HER2-negative can evolve into HER2-positive disease.
    • An analysis of more than 3,000 patients demonstrated a low risk for recurrence 5 to 10 years after an initial HER2 breast cancer diagnosis. This finding was especially strong among patients with either no cancer spread to the lymph nodes (3.23%), or cancer spread to only one to three axillary lymph nodes (6.39%).
    • In HER2 treatment regimens, targeted therapy may improve the efficacy of other treatment types and show activity against the cancer when chemotherapy does not work. HER2 targeted drugs include monoclonal antibodies, such as trastuzumab, pertuzumab and ado-trastuzumab emtansine, and kinase inhibitors such as lapatinib and neratinib.
    • While the side effects of targeted drugs are generally mild, serious side effects such as heart damage can lead to congestive heart failure. For most women, this side effect lasts for a brief time and resolves after stopping the drug. The risk for heart problems is elevated when these agents are given along with some chemotherapy drugs that may also lead to heart damage.
    • It is not fully known what causes abnormalities in the HER2 gene, but the environment, genes and lifestyle may play a role. While experts have suggested that there may be a genetic component to HER2, it is believed that a “bad” HER2 gene cannot be inherited and the gene abnormality is not hereditary.

    References

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    her2-positive breast cancer
    hormone receptor-positive breast cancer