Treatment given to weaken and destroy breast cancer BEFORE surgery is called neoadjuvant treatment. Treatment before surgery isn't routinely used to treat early-stage breast cancer, but may be used if the cancer is large or aggressive. Treatment before surgery is more commonly used 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 usually the neoadjuvant treatments used.
Two studies looked at neoadjuvant treatment for HER2-positive breast cancer.
One study, called NeoALTTO, found that giving both Herceptin (chemical name: trastuzumab) and Tykerb (chemical name: lapatinib) with the chemotherapy medicine Taxol (chemical name: paclitaxel) before surgery to treat early-stage or locally advanced HER2-positive breast cancer offered more benefits than giving only Herceptin and Taxol or only Tykerb and Taxol.
The other study, called GeparQuinto, found that Herceptin given with chemotherapy is more effective than Tykerb given with chemotherapy before surgery to treat early-stage or locally advanced HER2-positive breast cancer.
Results from the two studies were published online in The Lancet on Jan. 17, 2012.
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 treatment before surgery 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. Tykerb is a pill taken by mouth.
Herceptin and Tykerb aren't approved by the U.S. Food and Drug Administration to be used before surgery to treat early-stage breast cancer, but doctors sometimes use Herceptin that way.
In the NeoALTTO study, 455 women diagnosed with early-stage or locally advanced HER2-positive breast cancer got one of three treatment regimens before surgery:
- Taxol and Herceptin
- Taxol and Tykerb
- Taxol, Herceptin, and Tykerb
After the treatment regimen 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. When no cancer cells are in the removed tissue, doctors call it a "pathologic complete response." Some doctors believe a pathologic complete response to treatment before surgery means the cancer is less likely to come back (recurrence).
A pathologic complete response was much more likely in women who got the regimen that included both Herceptin and Tykerb.
Pathologic complete response rates were:
- 29.5% in women who got Taxol and Herceptin
- 24.7% in women who got Taxol and Tykerb
- 51.3% in women who got Taxol, Herceptin, and Tykerb
The combination of Taxol, Herceptin, and Tykerb seemed most beneficial for women diagnosed with hormone-receptor-negative cancers.
Herceptin and Tykerb fight against HER2-positive breast cancers in different ways. This might explain why combining the two offered more treatment benefit than either one alone.
In the GeparQuinto study, 620 women diagnosed with early-stage or locally advanced HER2-positive breast cancer got a regimen of Cytoxan (chemical name: cyclophosphamide) and Ellence (chemical name: epirubicin) followed by Taxotere (chemical name: docetaxel) before surgery.
Half the women also got Herceptin as part of the treatment regimen before surgery; the other half got Tykerb.
After the treatment regimen was done, the women had surgery to remove the cancer. The researchers found that a pathologic complete response was more likely in women who got the regimen that included Herceptin (30.3%) before surgery compared to women who got Tykerb (22.7%).
Diarrhea, sometimes severe, can be a side effect of both Herceptin and Tykerb. Diarrhea also can be a side effect of chemotherapy. In the GeparQuinto study, severe diarrhea was more common in women who got Tykerb compared to women who got Herceptin.
A number of women in the GeparQuinto study stopped taking Herceptin or Tykerb or stopped the entire neoadjuvant regimen because of serious side effects, including severe diarrhea. Stopping treatment also was more common in women who got Tykerb. Although heart problems can be a side effect of either Herceptin or Tykerb, heart problems weren't a major side effect in these two studies.
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 whether treatment before surgery makes sense for you and ask about these two studies.
If your doctor does recommend treatment before surgery that includes a targeted therapy, results from the GeparQuinto study suggest that Herceptin would be the better choice. The NeoALTTO study results suggest that using BOTH Herceptin and Tykerb before surgery to treat early-stage or locally advanced HER2-positive breast cancer might make sense.
More research is being done that will help doctors understand how best to use these targeted therapies in combination before and after surgery. The ALTTO study, which is related to the NeoALTTO study, is looking at the best way to use Herceptin and Tykerb AFTER surgery to treat HER2-positive breast cancer.
Stay tuned to Breastcancer.org for updates on research aimed at finding better ways to treat both early-stage and advanced-stage breast cancer.