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More Frequent Chemotherapy Shows Improved Results for Breast Cancer Patients (dateline April 14, 2003)

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
  • To learn more about chemotherapy, please visit