Women with HER2-positive breast cancer will most often receive a combination of treatments. These may include neoadjuvant therapy to reduce the tumor size before surgery and adjuvant (additional) therapy to help keep cancer from returning.
Effective targeted treatments exist for HER2-positive cancers. These are often more effective than other breast cancer treatments.
Treatment Options
A breast cancer diagnosis can be frightening, especially when it’s HER2-positive. But the good news is that HER2 breast cancers are more treatable than ever. Research into the HER2 gene and protein has led to new drug treatments that dramatically improve survival and prognosis for people with this type of cancer.
When a person receives the diagnosis, their healthcare team will use several tests to learn more about the condition. The test results will give doctors important information, such as whether the cancer has spread (metastasized) or the chance it will return.
The healthcare team can then design a treatment plan. This may include surgery, which involves removing all of the breasts. It might also include chemotherapy, which uses drugs to destroy cancer cells. The plan might also have other treatments, such as targeted and radiation therapy.
Targeted therapy works by targeting specific proteins that help cancer cells grow. Examples of HER2-targeted therapies include Trastuzumab (Herceptin), pertuzumab (Perjeta), and lapatinib (Tykerb). In addition, a newer medication called neratinib (Nerlynx) is a kinase inhibitor that blocks the activity of the HER2 protein. It is given orally and can be used in addition to Trastuzumab for people with HER2-positive early-stage breast cancer that has not recurred.
Prognosis
HER2 positive breast cancer grows faster and spreads more widely than other breast cancers. This makes it harder to cure. But thanks to research, survival rates have improved over time.
Cancer survival rates show how many people with a particular type of cancer survive for five years after they are diagnosed. These statistics are usually given as percentages, such as 75%. They can tell you what to expect from your treatment and how it might affect your life. But remember that survival rates don’t tell you what will happen to you or a loved one. They are averages based on all women with this specific type of cancer.
Doctors use a combination of treatments to help treat HER2-positive breast cancers. They can include surgery, chemotherapy and other medicines that target HER2 and other parts of the cancer cell. They may also prescribe medications that lower estrogen levels or prevent a woman’s body from producing more hormones.
The discovery of HER2 as an actionable target changed how doctors treated cancers. The first HER2-targeted drug, Trastuzumab (Herceptin), was approved almost 25 years ago. Since then, scientists have discovered and developed several HER2-targeted other medicines. They are exploring new drugs and combinations that could improve outcomes even further.
Molecular Testing
HER2 receptor on cancer cells allows them to grow and spread. When breast cancer is HER2 positive, it is more likely to be aggressive and may recur, or return, after treatment. However, targeted therapies are improving and lowering the risk that HER2-positive cancers will recur.
HER2-directed therapies block the protein that signals tumor cells to grow and divide. They can be used alone or in combination with standard chemotherapy drugs. HER2-directed treatment can reduce the chance of cancer recurrence after surgery and extend survival.
To determine if a tumor is HER2 positive, doctors will examine a sample of your breast cancer tissue. They will test it for the HER2 gene to determine whether multiple gene copies exist (HER2 amplification). They will also measure how much HER2 is on the surface of your tumor cells by using immunohistochemistry. The results of the HER2 test will give a score between zero and three. Tumors with scores of two or more are HER2 positive.
If you have a HER2+ tumor, your doctor will probably recommend hormone therapy. This treatment can help prevent cancer from growing or spreading by blocking the estrogen and progesterone that normal breast cells need to survive. Your doctor might suggest radiation therapy. This treatment uses high-energy X-rays to destroy cancer cells left after surgery or those that have spread to other body parts.
Genetic Testing
Besides cancer stage and tumor grade, the HER2 status of your breast cancer determines how aggressive the disease is and which treatments are available. HER2 status is determined by the presence or absence of certain proteins called HER2 receptors in your body’s cells. You can learn your HER2 status with a simple blood test.
HER2 testing is important for anyone diagnosed with invasive HER2-positive breast cancers, including those in the neoadjuvant (before surgery), adjuvant (after surgery), or metastatic (cancer that has spread to other parts of the body) stages. The treatment options available to HER2-positive patients have greatly improved since the introduction of Trastuzumab and other HER2-targeted therapies, which have become the standard of care in the neoadjuvant and adjuvant settings and are currently being used in the metastatic setting as well.
Genetic tests can help identify if you are more likely to develop HER2-positive cancers, especially if you have a strong family history. These tests look for specific BRCA1 and BRCA2 gene variants that increase your risk of developing hereditary breast cancer. We recommend germline (inherited) BRCA1/BRCA2 genetic testing only on a case-by-case basis in individuals with striking personal and family histories of HER2-positive cancers who receive uninformative negative extended multigene panel results.
