After breast cancer surgery, many women diagnosed with early-stage, HER2-positive breast cancer are treated with the targeted therapy Herceptin (chemical name: trastuzumab) and a combination of chemotherapy medicines. Because these treatments are given after surgery, they're called adjuvant therapies. These adjuvant therapies are used to reduce the risk of the cancer coming back (recurrence).
An anthracycline chemotherapy medicine is typically part of the combination used to treat HER2-positive breast cancer. Adriamycin (chemical name: doxorubicin) and Ellence (chemical name: epirubicin) are anthracyclines. Like all chemotherapy medicines, anthracyclines may cause serious side effects including heart damage, which can lead to heart failure. Doctors also are concerned about a higher risk of leukemia in women who have been treated with Adriamycin. Because of these potential risks, chemotherapy without an anthracycline could makes sense for some women, as long as there's no increase in recurrence risk.
A study compared three adjuvant treatment plans for women diagnosed with HER2-positive, early-stage breast cancer and found that Herceptin plus chemotherapy that didn't include an anthracycline was as effective as Herceptin plus chemotherapy that did include an anthracycline. Women who didn't get an anthracycline had the same risk of recurrence as women who got an anthracycline. Women who didn't get an anthracycline also had a lower risk of certain side effects, including heart failure. These results were reported at the 2009 San Antonio Breast Cancer Symposium.
After surgery, 3,222 women diagnosed with HER2-positive, early-stage breast cancer got one of three adjuvant therapy plans:
- Herceptin plus the chemotherapy medicines Adriamycin, Cytoxan (chemical name: cyclophosphamide), and Taxotere (chemical name: docetaxel); this combination is called ACTH
- Herceptin plus the chemotherapy medicines carboplatin (brand name: Paraplatin) and Taxotere; this combination is called CTH
- the chemotherapy medicines Adriamycin, Cytoxan, and Taxotere; this combination is called ACT
The women were followed for more than 5 years.
The women who got Herceptin and chemotherapy without the anthracycline Adriamycin (CTH) did just as well as women who got Herceptin and chemotherapy with Adriamycin (ACTH):
- 81% of women who got Herceptin and chemotherapy with no Adriamycin were alive and didn't have a recurrence
- 84% of women who got Herceptin and chemotherapy with Adriamycin were alive and didn't have a recurrence
This very small difference wasn't statistically significant, which means it could have been due to chance and not because of the different treatments.
Women who got chemotherapy but no Herceptin (ACT) didn't do as well as women who got Herceptin:
- 75% of women who got ACT were alive and didn't have a breast cancer recurrence
The difference in survival and recurrence rates between women who did and didn't get Herceptin was statistically significant, which means the difference was likely due to the Herceptin and not just because of chance.
This study also showed that even women with an extremely high risk of recurrence got no additional benefits from Adriamycin as long as they got Herceptin.
No matter which treatment they got, the overall rate of side effects was similar for all the women. About 2% of women who got Adriamycin developed heart failure, which was 5 times higher than in women who didn't get Adriamycin.
Based on these results, some doctors think not using Adriamycin in the adjuvant chemotherapy combination for women diagnosed with HER2-positive, early-stage breast cancer makes sense as long as Herceptin is included. Other doctors think that more research is needed before they confidently can avoid using Adriamycin.
Most doctors would agree that Herceptin makes a difference and should be used to treat almost all women diagnosed with HER2-positive breast cancer. Still, some doctors say that the difference Herceptin makes is small and that the expense of Herceptin ($10,000 per month) makes adjuvant chemotherapy without Herceptin a reasonable alternative for some women.
If you've been diagnosed with HER2-positive, early-stage breast cancer, your doctor will likely recommend Herceptin and a chemotherapy combination after surgery to lower the risk of the cancer coming back. Your doctor may recommend a chemotherapy plan that includes an anthracycline such as Adriamycin. If so, you might want to talk to your doctor about the results of this study. Ask about your doctor's reasons for recommending Adriamycin and the benefits, risks, and side effects of all the medicines being considered. Armed with the most-up-to-date information, you and your doctor can decide on a treatment plan that makes the most sense for your and your unique situation.