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Increasing the frequency of chemotherapy treatments may have
a positive effect for breast cancer patients, according to a study presented at a recent
breast cancer conference. The researchers found that administering chemotherapy every two
weeks instead of the standard interval of every three weeks, increased breast cancer
survival rates and decreased negative side effects from treatment. The concept behind the
"dose dense" chemotherapy treatment may apply to other types of cancer as well.
Chemotherapy, the use of anti-cancer drugs, is a common treatment for breast cancer as
well as many other types of cancers. In the case of breast cancer, chemotherapy may be
used after surgery to ensure that remaining cancer cells are destroyed, or before surgery
to help shrink the size of a tumor so it becomes operable. Because chemotherapy is a
systemic treatment, affecting the entire body, it can be associated with negative side
effects, most commonly nausea, vomiting, fatigue, and hair loss.
Using mathematical models developed by Dr. Richard Simon of the National Cancer
Institute and Dr. Larry Norton, formerly of the National Cancer Institute and now at
Memorial Sloan-Kettering Cancer Center, the researchers predicted that administering
chemotherapy treatments in closer duration would increase its effectiveness against
tumors. In essence, more frequent doses of chemotherapy drugs reduce the amount of time
cancer cells have to grow back between each treatment.
To test their hypothesis, lead researcher Dr. Clifford Hudis, Chief of the Breast
Cancer Medicine Service at Memorial Sloan-Kettering Cancer Center, and colleagues gave
2,005 breast cancer patients (whose cancer had spread to the lymph
nodes) either a standard chemotherapy regimen every three weeks, or the dose dense
chemotherapy regimen every two weeks. The women on the dose dense regimen also received a
drug called granulocyte colony stimulating factor to help grow white blood cells. The
chemotherapy regimen consisted of the drugs doxorubicin (brand name, Adriamycin),
paclitaxel (brand name, Taxol), and cyclophosphamide (brand name, Cytoxan).
The results of the study were presented at the annual San Antonio Breast Cancer
Conference in December 2002. After four years in the study, 82% of the women who received
dose dense chemotherapy every two weeks were disease-free versus 75% of the women who
received the chemotherapy at the standard interval of every three weeks. The women in the
dose dense group also less likely to develop neutropenia,
the loss of white blood cells, and finished their entire course of chemotherapy more
rapidly than women on the standard chemotherapy schedule.
While the researchers noted that the statistical comparisons in the study should be
considered preliminary, they are optimistic that the findings will trigger the adoption of
the new chemotherapy treatment schedule at several centers, in addition to the dozens of
centers that participated in the study. The researchers are also applying the same concept
to new trials with prostate and lung cancers.
Additional Resources and References
- The study, "Superiority of Dose-Dense over Conventional Scheduling and Equivalence
of Sequential vs. Combination Adjuvant Chemotherapy For Node-Positive Breast Cancer,"
was presented at the annual San Antonio Breast Cancer Conference in December 2002. An
abstract of the study is available online at http://www.sabcs.saci.org/
- To learn more about chemotherapy, please visit http://www.imaginis.com/breasthealth/chemo.asp
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