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. Treatments given after surgery are called adjuvant treatments. Adjuvant treatments are given 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 rapid-onset leukemia in women who've been treated with Adriamycin. Because of these risks, a chemotherapy combination with no anthracycline could make sense for some women -- as long as there's no increase in recurrence risk and no difference in survival.
A study has found that Herceptin plus chemotherapy that didn't include an anthracycline was as effective as Herceptin plus chemotherapy that included an anthracycline for women diagnosed with HER2-positive, early-stage breast cancer. Women who didn't get an anthracycline had the same risk of recurrence and the same overall survival as women who got chemotherapy with an anthracycline. Women who didn't get an anthracycline also had a lower risk of certain side effects, including heart failure and rapid-onset leukemia.
The results were published in the Oct. 6, 2011 issue of The New England Journal of Medicine.
After surgery, 3,222 women diagnosed with HER2-positive, early-stage breast cancer got one of three treatments:
- 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
- Adriamycin, Cytoxan, and Taxotere (no Herceptin); 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 were just as likely to be alive with no recurrence (disease-free survival) as the women who got Herceptin and chemotherapy with Adriamycin.
Five-year disease-free survival rates were:
- 81% for women who got Herceptin and no Adriamycin (CTH)
- 84% for women who got Herceptin and Adriamycin (ACTH)
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) were somewhat more likely to have a recurrence; 5-year disease-free survival for that group was 75%.
Overall survival (the proportion of women alive after 5 years, whether or not the cancer came back) was also about the same for the women who got Herceptin with Adriamycin (92%) and the women who got Herceptin and no Adriamycin (91%). Overall survival was worse for the women who got chemotherapy but no Herceptin (87%).
The difference in both disease-free survival and overall survival 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 a very high risk of recurrence got no additional benefits from Adriamycin as long as they got Herceptin.
Overall, side effect rates were about the same for all the women, no matter which treatment they got. Still, about 2% of the women who got Adriamycin developed heart failure, which was 5 times higher than the number of women who developed heart failure who didn't get Adriamycin. Seven of the women who got Adriamycin developed rapid-onset leukemia compared to one of the women who didn't get Adriamycin for breast cancer. This one woman did get Adriamycin to treat lymphoma.
Based on the results, some doctors think using a chemotherapy combination without Adriamycin to treat women diagnosed with HER2-positive, early-stage breast cancer after surgery makes sense as long as Herceptin is included. Other doctors think more research is needed before they can confidently avoid Adriamycin.
Most doctors would agree that Herceptin is effective and should be used in the post-surgery treatment plan for almost all women diagnosed with HER2-positive breast cancer. Still, some doctors feel that the difference Herceptin makes is small and that the expense of Herceptin ($10,000 per month) makes post-surgery chemotherapy without Herceptin (the ACT regimen, for example) a reasonable choice 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 plan that includes an anthracycline such as Adriamycin. If so, you might want to ask your doctor about this study, as well as why Adriamycin is recommended for you, and the benefits, risks, and side effects of all the medicines being considered. Together, you and your doctor can decide on a treatment plan that makes the most sense for you and your unique situation.