A study suggests that treating early-stage breast cancer with two common chemotherapy medicines followed by a third (doctors call this a sequential approach) has some advantages compared to giving two or three chemotherapy medicines at the same time. Still, the sequential approach made overall treatment time longer and the side effects of the treatment were more severe.
In this study, 5,351 women diagnosed with early-stage breast cancer had surgery to remove the cancer. Adjuvant chemotherapy was part of all the women's treatment after surgery. "Adjuvant" means treatments given after surgery to lower the risk of the cancer coming back (recurrence). The women were treated with two or three common chemotherapy medicines:
- 1/3 of the women got Adriamycin (chemical name: doxorubicin), Cytoxan (chemical name: cyclophosphamide), and Taxotere (chemical name: docetaxel) together for four cycles (called the concurrent ACT regimen)
- 1/3 of the women got Adriamycin and Taxotere together for four cycles (called the AT regimen)
- 1/3 of the women got Adriamycin and Cytoxan together for four cycles and then got four cycles of Taxotere (called the sequential ACT regimen)
The Taxotere dose used in the sequential ACT regimen was higher than the Taxotere dose used in either the concurrent ACT regimen or the AT regimen. The researchers used the higher dose because they wanted to see if using a higher dose of Taxotere after Adriamycin and Cytoxan would offer more benefits without the potential risk of more severe side effects when all three chemotherapy medicines are given at the same time.
The researchers tracked and compared treatment outcomes of the three groups over 8 years.
Overall survival was:
- 17% better in women who got the sequential ACT regimen compared to women who got the AT regimen
- 14% better in women who got the sequential ACT regimen compared to women who got the concurrent ACT regimen (though this survival difference wasn't statistically significant, which means that it could have due to chance rather than because of the different treatments)
Disease-free survival (survival without the cancer coming back) 8 years after treatment:
- 74% of the women who got the sequential ACT regimen were alive and had not had the cancer come back
- 69% of the women who got either the AT regimen or the concurrent ACT treatment were alive and had not had the cancer come back
Risk of recurrence was:
- 20% lower in women who got the sequential ACT regimen compared to women who got the AT regimen
- 17% lower in women who got the sequential ACT regimen compared to women who got the concurrent ACT regimen
Treatment side effects:
- 65% of women who got the sequential ACT regimen had serious side effects (called grade 3 or grade 4 adverse events)
- 48% of women who got the concurrent ACT regimen had serious side effects
- 45% of women who got the AT regimen had serious side effects
The higher rate of serious side effects seems to be related to the higher dose of Taxotere used in the sequential ACT regimen.
Overall, the sequential ACT regimen improved treatment outcomes a little bit, but did increase the risk of more serious side effects.
If chemotherapy will be part of your treatment plan after surgery to remove breast cancer, your doctor will consider a number of factors about your specific situation when recommending the regimen that makes the most sense for you. You may want to ask your doctor about the sequential ACT regimen studied here and if a sequential chemotherapy approach is a good option for you.
On the Breastcancer.org Choosing a Chemotherapy Combination page you can learn more about the most common chemotherapy regimens used to treat breast cancer and the factors you and your doctor will consider when deciding on the best regimen for YOU.
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