Treatment given to weaken and destroy breast cancer BEFORE surgery is called neoadjuvant treatment. Neoadjuvant treatment isn't routinely used to treat early-stage breast cancer, but may be used if the cancer is large or aggressive. Neoadjuvant treatment is more commonly used before surgery for breast cancer that has spread outside the breast to other tissue in the breast area (locally advanced breast cancer). One or more chemotherapy medicines are typically used for neoadjuvant treatment.
A study found that adding both Herceptin (chemical name: trastuzumab) and Tykerb (chemical name: lapatinib) to the chemotherapy medicine paclitaxel (brand name: Taxol) in a neoadjuvant treatment regimen for women diagnosed with early-stage or locally advanced HER2-positive breast cancer offered more benefits than regimens with only Herceptin and Taxol or only Tykerb and Taxol. The results were presented at the 2010 San Antonio Breast Cancer Symposium (SABCS).
HER2-positive breast cancers have too many copies of the HER2/neu gene, which make too much of the HER2 protein. HER2-positive breast cancers tend to be aggressive, so neoadjuvant treatment may be recommended. Herceptin and Tykerb are targeted therapies that fight against HER2-positive breast cancers by blocking the cancer cells' ability to receive growth signals. Herceptin is given intravenously, which means it’s delivered directly into your bloodstream through an IV or a port. A newer form of Herceptin, Herceptin Hylecta (chemical name: trastuzumab and hyaluronidase-oysk), can be given as an injection. Tykerb is a pill taken by mouth.
Herceptin isn't approved by the U.S. Food and Drug Administration (FDA) to be used before surgery for early-stage breast cancer, but doctors sometimes use it that way. Tykerb also isn't approved to be used before surgery to treat early-stage breast cancer.
In this study, called Neo-ALTTO, 455 women diagnosed with early-stage or locally advanced HER2-positive breast cancer got one of three neoadjuvant treatment regimens:
- paclitaxel and Herceptin
- paclitaxel and Tykerb
- paclitaxel, Herceptin, and Tykerb
After the neoadjuvant treatment was done, the women had surgery to remove the cancer. The researchers recorded how many women had no active cancer cells in the tissue removed during surgery. When there are no cancer cells in the tissue removed, doctors call it a "pathologic complete response." Some doctors believe a pathologic complete response to neoadjuvant treatment means the cancer is less likely to come back (recurrence).
A pathologic complete response was much more likely in women who got the neoadjuvant regimen with both Herceptin and Tykerb.
The pathologic complete response rates were:
- 29.5% in women who got paclitaxel and Herceptin
- 24.7% in women who got paclitaxel and Tykerb
- 51.3% in women who got paclitaxel, Herceptin, and Tykerb
The combination of paclitaxel, Herceptin, and Tykerb seemed most beneficial for women diagnosed with hormone-receptor-negative cancers.
While these results are promising, experts believe it's too early to conclude that using both Herceptin and Tykerb in a neoadjuvant regimen to treat early-stage HER2-positive breast cancer makes sense. Still, more research is being done that will help doctors understand how best to use these targeted therapies before and after surgery. ALTTO, a study related to Neo-ALTTO, is looking at the best way to use Herceptin and Tykerb after surgery to treat HER2-positive breast cancer.
If you've recently been diagnosed with HER2-positive breast cancer and haven't had surgery yet, you might want to talk to your doctor about this study and whether treatment before surgery makes sense for you.
Editor’s Note: This article was updated with information about Herceptin Hylecta, which the FDA approved on Feb. 28, 2019.