After surgery to remove early-stage breast cancer, chemotherapy often is given to destroy any breast cancer cells that may remain in the body and reduce the risk of the cancer coming back (recurrence). Doctors call chemotherapy given after surgery adjuvant chemotherapy.
A number of chemotherapy medicines given alone or in combination are used as adjuvant chemotherapy, including a class of medicines called anthracyclines.
Results from an analysis of several studies found that chemotherapy regimens that include an anthracycline are better than a regimen that doesn’t include an anthracycline for women diagnosed with early-stage, HER2-negative breast cancer with a high risk of recurrence.
The research was published online on April 11, 2017. Read the abstract of “Anthracyclines in Early Breast Cancer: The ABC Trials -- USOR 06-090, NSABP B-46-I/USOR 07132, and NSABP B-49 (NRG Oncology).”
Anthracycline chemotherapy medicines are:
- Adriamycin (chemical name: doxorubicin)
- Ellence (chemical name: epirubicin)
- Doxil (chemical name: doxorubicin)
- daunorubicin (brand names: Cerubidine, DaunoXome)
- mitoxantrone (brand name: Novantrone)
Anthracyclines work by damaging cancer cells’ genes and interfering with their reproduction.
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 concerns, many doctors started using a chemotherapy regimen that did not include an anthracycline after surgery, so there was a decline in anthracycline use.
Still, doctors want to be sure that they are treating women with the most effective chemotherapy regimen possible.
The studies included 4,156 women who had had surgery to remove early-stage, HER2-negative breast cancer with a high risk of recurrence. The women were randomly assigned to receive one of two chemotherapy regimens:
- 2,062 women were treated with Adriamycin, Cytoxan (chemical name: cyclophosphamide), with Taxol (chemical name: paclitaxel) or Taxotere (chemical name: docetaxel) -- the anthracycline regimen, called TaxAC for short
- 2,094 women were treated with Taxotere and Cytoxan -- the non-anthracycline regimen, called TC for short
About half the women were followed for less than 3 years and the other half of the women were followed for more than 3 years. The researchers recorded how long the women lived without a recurrence of invasive breast cancer, called invasive disease-free survival.
During follow-up, more women treated with the TC regimen had a recurrence than women treated with TaxAC:
- 179 women treated with TC had a recurrence
- 121 women treated with TaxAC had a recurrence
This difference was statistically significant, which means that it was likely due to the difference in chemotherapy regimens and not just because of chance.
Overall, 4-year invasive disease-free survival rates were:
- 90.7% for the TaxAC regimen
- 88.2% for the TC regimen
The results strongly suggest that the anthracycline regimen is slightly better than the regimen without an anthracycline for women diagnosed with early-stage, HER2-negative breast cancer with a high risk of recurrence.
The researchers also looked at specifically defined cancer characteristics to see if there were certain groups of women who would do well without an anthracycline in the regimen or groups of women who would get more benefits from a regimen that included an anthracycline:
- For women with hormone-receptor-positive disease with no cancer in the lymph nodes (node negative), the TC regimen reduced recurrence risk by about 2.5% more than the TaxAC regimen.
- For women with hormone-receptor-positive disease with one to three positive nodes, the TaxAC regimen reduced recurrence risk 2% more than the TC regimen.
- For women with hormone-receptor-positive disease with four or more positive lymph nodes, the TaxAC regimen reduced recurrence risk 5.8% more than the TC regimen.
- For women with triple-negative disease (hormone-receptor-negative and HER2-negative) with no cancer in the lymph nodes, the TaxAC regimen reduced recurrence risk by 2.5% more than the TC regimen.
- For women with triple-negative disease with one to three positive nodes, the TaxAC regimen reduced recurrence risk by 10.9% more than the TC regimen.
- For women with triple-negative disease with four or more positive nodes or women with triple-negative disease with one or more positive nodes, the TaxAC regimen reduced recurrence risk by about 11% more than the TC regimen.
“I don’t think these early results change practice, but they validate what many of us have been doing,” said Paul Gilman, M.D., chief of the Hematology/Oncology Division at Lankenau Hospital. Dr. Gilman is a member of the Breastcancer.org Professional Advisory Board. “The results give us guidance on which women seem to benefit from anthracycline chemotherapy and which women will do just as well with the TC regimen.”
It's important to know that the regimen of Taxotere and Cytoxan was given for six cycles in the studies. Four cycles is usually the timing of this regimen.
You and your doctor will consider several important factors when deciding on a chemotherapy regimen:
- The characteristics of the cancer: The cancer’s stage, hormone-receptor status, HER2 status, and lymph node status will influence the chemotherapy regimen your doctor recommends.
- Your age, menopausal status, and general health: Your doctor will take into account your age, general health, and menopausal status when recommending a chemotherapy regimen. If you have high blood pressure, are older than 60, and have a history of heart problems, your doctor will probably recommend a chemotherapy regimen that doesn’t include an anthracycline.
Deciding on the best chemotherapy regimen can be a bit of a balancing act. You want a combination that offers the most benefits with the least risks and side effects. It’s important to remember that while there are many standard chemotherapy regimens, each person’s treatment plan will be unique because each cancer is unique.
If you’ll be having chemotherapy to treat breast cancer, it’s a good idea to ask your doctor why a specific regimen is recommended for you. If your recommended regimen doesn’t include an anthracycline and you have no history of heart problems or high blood pressure, you might want to ask your doctor why. Together, you and your doctor will make the best decision for your unique situation.
For more information on chemotherapy, including how it works and standard chemotherapy combinations, visit the Breastcancer.org Chemotherapy section.