Metastatic breast cancer is cancer that has spread to parts of the body away from the breast. Breast cancer can spread to bones, the lungs, the liver, and the brain. Metastatic breast cancer is treatable, but generally not curable. About 30% to 40% of women with metastatic breast cancer have the cancer spread to the brain.
A study found that using Tykerb (chemical name: lapatinib) with Herceptin (chemical name: trastuzumab) and chemotherapy to treat women diagnosed with metastatic, HER2-positive breast cancer improved survival compared to only Herceptin and chemotherapy.
The results were published in the Journal of Clinical Oncology and presented at the 2011 annual meeting of the American Society of Clinical Oncology (ASCO).
Treating metastatic breast cancer in the brain is aimed at weakening and shrinking the cancer. Sometimes doctors will surgically remove the cancer if it's possible to do so. If surgery isn't possible, the cancer may be treated with radiation therapy to the brain (whole brain irradiation). Surgery and radiation therapy are called local therapies. Chemotherapy and targeted therapies such as Tykerb and Herceptin are called systemic treatments.
Herceptin and Tykerb are targeted therapies used to treat HER2-positive breast cancer. HER2-positive cancers make too much of the HER2 protein. The HER2 protein sits on the surface of cancer cells and receives signals that encourage the cancer cells to grow and spread. About one out of every four breast cancers is HER2-positive. Herceptin and Tykerb work by blocking the HER2 protein's ability to make HER2-positive breast cancers grow.
Herceptin, given intravenously, is approved by the U.S. Food and Drug Administration (FDA) to:
- treat advanced-stage, HER2-positive breast cancers
- lower the risk of recurrence of early-stage, HER2-positive breast cancers with a high risk of recurrence
Tykerb, a pill taken by mouth, is approved by the FDA to be used:
- in combination with Xeloda to treat HER2-positive, metastatic breast cancers that have stopped responding to certain chemotherapy medicines and Herceptin
- in combination with the hormonal therapy Femara (chemical name: letrozole) to treat postmenopausal women diagnosed with hormone-receptor-positive, HER2-positive, advanced-stage breast cancer
In this study, researchers looked at the treatments and outcomes of 80 women diagnosed with HER2-positive breast cancer that had spread to the brain:
- 28 women were treated with local therapy followed by Herceptin alone or Herceptin and chemotherapy.
- 15 women were treated with local therapy followed by both Herceptin and Tykerb, with or without chemotherapy.
- 37 women were treated with local therapy and chemotherapy, but no Herceptin or Tykerb (the women were treated before 2003 when targeted therapies for breast cancer weren't available).
The researchers figured out the median survival of the women in the treatment groups. Median survival means half the women lived for a shorter time and half lived for a longer time.
Median survival times were:
- 9 months for women who got local therapy followed by only chemotherapy (no Herceptin and no Tykerb)
- 13 months for women who got local therapy followed by systemic therapy that included Herceptin but not Tykerb
- more than 24 months for women who got local therapy followed by systemic therapy that included BOTH Herceptin and Tykerb
Because the results are positive, the researchers believe that most women diagnosed with HER2-positive breast cancer that has spread to the brain should be treated with both Herceptin and Tykerb after local therapy.
If you have been diagnosed with breast cancer that has spread to the brain, your doctor will work with you to plan treatments that make the most sense for your unique situation. If the cancer is HER2-positive, targeted therapies may be in your treatment plan. You may want to talk to your doctor about this study and if both Herceptin and Tykerb would be good options for you.
You can learn more about Herceptin and Tykerb in the Breastcancer.org Targeted Therapies section.