Many women diagnosed with early-stage breast cancer with a high risk of recurrence (the cancer coming back) get chemotherapy after surgery to reduce the risk of recurrence. In some cases, the chemotherapy may be given on a dose-dense schedule.
Dose-dense chemotherapy means that the chemotherapy medicines are given every 2 weeks instead of the standard schedule of every 3 weeks. Doctors may recommend a dose-dense regimen for some women because other research has shown that this approach can improve survival and decrease the risk of recurrence more effectively than a standard chemotherapy schedule.
Dose-dense chemotherapy regimens are used more often in the United States than they are in Europe.
Tailored chemotherapy means that the dose and/or the chemotherapy medicines used are specific to each person, based on the person’s body mass, blood counts, and the characteristics of the cancer.
A study has found that tailored dose-dense chemotherapy didn’t lengthen the time until the cancer came back in women diagnosed with early-stage breast cancer with a high risk of recurrence.
The research was published in the Nov. 8, 2016 issue of the Journal of the American Medical Association. Read the abstract of “Effect of Tailored Dose-Dense Chemotherapy vs Standard 3-Weekly Adjuvant Chemotherapy on Recurrence-Free Survival Among Women With High-Risk Early Breast Cancer: A Randomized Clinical Trial.”
In the study, called the PANTHER (Pan-European Tailored Chemotherapy) trial, 2,017 women diagnosed with early-stage breast cancer with a high risk of recurrence were randomly assigned to receive either tailored dose-dense chemotherapy or a standard chemotherapy regimen:
- 1,006 women received 4 cycles of dose-dense Ellence (chemical name: epirubicin) and Cytoxan (chemical name: cyclophosphamide) every 2 weeks followed by 4 cycles of tailored dose-dense Taxotere (chemical name: docetaxel) every 2 weeks -- this was the tailored dose-dense group
- 1,011 women received 3 cycles of fluorouracil and Ellence-Cytoxan every 3 weeks followed by 3 cycles of Taxotere every 3 weeks -- this was the standard regimen group
Other details of the study:
- the women were age 65 or younger
- 80% of the cancers were hormone-receptor-positive
- 97% of the cancers were node-positive
- half the women were followed for fewer than 5.3 years, the other half were followed for more time
The study took place at 86 sites in Sweden, Germany, and Austria between February 2007 and September 2011.
The researchers found that the 5-year recurrence-free survival rates were about the same for both groups of women:
- 89% for the tailored dose-dense group
- 85% for the standard regimen group
Overall survival at 5 years also was about the same:
- 92% for the tailored dose-dense group
- 90% for the standard regimen group
Overall survival is how long the women lived, with or without the cancer recurring.
Finally, 5-year distant disease-free survival also was about the same for both groups:
- 89% for the tailored dose-dense group
- 87% for the standard regimen group
Distant disease-free survival is how long the women lived without the cancer coming back in a part of the body away from the breast, such as the bones or liver.
Overall, the women in the tailored dose-dense chemotherapy group had better breast cancer event-free survival rates (87%) than women in the standard chemotherapy regimen group (82%). This difference was significant, which means that it was likely due to the difference in treatment and not just because of chance.
Breast cancer event-free survival is how long the women lived without a recurrence, distant recurrence, or diagnosis of a new breast cancer.
Still, women who were treated with tailored dose-dense chemotherapy had more severe side effects than women treated with standard chemotherapy:
- 53% of women who received tailored dose-dense chemotherapy had severe side effects
- 37% of women who received standard chemotherapy had severe side effects
“Dose escalation led, as expected, to a worsening of health-related quality-of-life measures during treatment and an increase of grade 3 or 4 adverse effects, but no toxic deaths and no increase in secondary malignant neoplasms,” the researchers wrote.
This study didn’t find any advantages to a tailored dose-dense chemotherapy regimen compared to a standard regimen for women diagnosed with early-stage breast cancer with a high risk of recurrence. But other studies have suggested that dose-dense chemotherapy may offer benefits for premenopausal women diagnosed with early-stage breast cancer with a high risk of recurrence.
The researchers who did the PANTHER study did conclude that analyzing the data from each person in studies on dose-dense chemotherapy would help researchers figure out if tailored dose-dense chemotherapy should be used for specific groups of women.
It’s also important to know that Ellence and Taxotere are more commonly used in Europe, so this study may not reflect standards of care in the United States. A typical U.S. dose-dense chemotherapy regimen is more likely to use Adriamycin (chemical name: doxorubicin) and Cytoxan followed by Taxol (chemical name: paclitaxel).
If you’ve been diagnosed with early-stage breast cancer that has a high risk of recurrence, it’s likely that chemotherapy will be part of your treatment plan. If you’re a premenopausal woman, some research suggests that dose-dense chemotherapy may offer more benefits than a standard regimen. Still, a dose-dense regimen is likely to cause more severe side effects. After you consider all the characteristics of the cancer, as well as your unique situation, preferences, and any other health conditions you may have, you and your doctor can make the best choices for you.
Visit the Breastcancer.org Chemotherapy section to learn more about what to expect during chemotherapy.