Targeted therapies are treatments that target specific proteins or markers on or within cancer cells that help the cells to grow. Targeted therapies may be used alone or with other targeted therapies, hormonal therapies or chemotherapy medicines. Your doctor may also call these treatments tailored or biologic therapies.
- If the breast cancer tests positive for the HER2 receptor, you may be able to receive a targeted therapy that only targets HER2-positive cells
- Medicines that block the growth of blood vessels that most tumors need to grow
- Therapies that work like antibodies made by the immune system
Unlike chemotherapy, targeted therapies only kill only cells with that particular target, meaning fewer effects on healthy cells. For this reason, targeted therapies by themselves have far fewer side effects than chemotherapy medicines. But each targeted therapy has unique side effects that you should discuss with your doctor.
Hormonal therapies targeting the estrogen receptor and the progesterone receptors are the earliest examples of targeted therapy. Some targeted therapies can be used along with hormonal therapy to make hormonal therapy more effective at killing the cancer.
There are many kinds of targeted therapy, and researchers will likely find others as they learn more about what makes certain cancers grow. Targeted treatments are helping scientists and doctors personalize treatment plans so they can better treat different types of cancer.
Many forms of targeted therapy are being tested in clinical trials. They are given intravenously (by vein) or by mouth as a pill. Some treatments have already been approved by the FDA, but others are only available in clinical trials.
You will need tests to know whether the cancer will respond to targeted therapy. Sometimes, you may be offered a targeted therapy only in specific situations. You may be offered targeted therapy if you have
- early-stage HER2-positive breast cancer
- metastatic HER2-positive breast cancer
- metastatic hormone receptor-positive, HER2-negative breast cancer, and you already went through menopause
If you are interested in other targeted therapies, ask your doctor about a clinical trial.
Targeted therapy for breast cancer can be given either:
- before surgery, which is called neoadjuvant therapy, or
- after surgery, which is called adjuvant therapy.
You may be able to get neoadjuvant therapy if you have a HER2-positive tumor that is too large to remove with lumpectomy. The goal of neoadjuvant therapy would be to shrink the tumor to a size that could allow you to have lumpectomy instead of mastectomy.
Neoadjuvant therapy may change the timing of your treatment or allow you to avoid mastectomy, but studies show it does not lengthen life, or survival, over receiving therapy after surgery.
Targeted medicines that may be used as neoadjuvant therapy for HER2-positive breast cancer are
- trastuzumab (Herceptin)
- pertuzumab (Perjeta)
- Pertuzumab is given with trastuzumab and chemotherapy before surgery. Afterward, you would continue taking trastuzumab to finish your treatment
After your surgery, a pathologist will check the tissue that was removed for any signs of cancer. In some cases, there may be a complete response to therapy, meaning the doctor can find no evidence of remaining disease, or NED. When cancer completely goes away, it is linked to better overall outcomes. But you will still need to finish your treatment plan to lessen your risk for cancer return.
Adjuvant TherapyAdjuvant therapy is treatment given after surgery to lower the risk of the breast cancer coming back and increase the chance of long-term survival. The goal is to kill any cancer cells that may have traveled away from the breast or lymph nodes. If you are at higher risk of recurrence, you are more likely to need adjuvant therapy.
A number of other targeted therapy medicines are approved only for metastatic breast cancer. These are
Many forms of neoadjuvant and adjuvant targeted therapy are being tested in clinical trials. Talk with your doctors about open clinical trials that may be available to you. You can also visit our section on Clinical Trials and Research Studies for more information.