New Studies Highlight Advances in Chemotherapy for Breast Cancer (dateline October 11, 2002)
Two studies discussed at the annual meeting of the American Society of Clinical Oncology (ASCO) may help improve the use of chemotherapy in breast cancer patients. The first study finds that the drug Taxotere (generic name, docetaxel) significantly reduces the chances that early-stage breast cancer will return after treatment. Meanwhile, the second study finds that chemotherapy administered before the drug tamoxifen (brand name, Nolvadex) can benefit breast cancer patients more than if the treatments are given at the same time after breast cancer surgery. An ASCO spokesperson said the two studies will influence the treatment of thousands of breast cancer patients.
Chemotherapy involves the use of anticancer drugs to help control or prevent the growth of tumors. The treatment is often used as an adjuvant (supplemental) therapy in breast cancer patients, in addition to surgery, radiation, drugs, or other therapies.
In the first study discussed at the ASCO meeting, researchers studied the effectiveness of the chemotherapy drug Taxotere in 1,500 early-stage breast cancer patients (Taxotere is often used in patients with advanced, metastatic breast cancer). Researcher Jean-Marc Nabholtz, MD, Chairman of the Breast Cancer International Research Group, and his colleagues analyzed the use of Taxotere in combination with doxorubicin (brand name, Adriamycin) and cyclophosphamide (brand name, Cytoxan) in one-half of the women. This treatment regimen is called TAC. They then compared the TAC chemotherapy regimen with another standard regimen called FAC (5-fluorouracil plus doxorubicin and cyclophosphamide), which was given to the other 750 women in the study. All of the women had previously undergone surgery to remove their breast tumors.
After following the women for three years, the researchers found that Taxotere (when combined with doxorubicin and cyclophosphamide) reduced the risk of a recurrence of breast cancer by 32%, compared to the standard FAC chemotherapy regimen. According to Dr. Nabholtz and his colleagues, the TAC chemotherapy regimen was especially beneficial in early-stage breast cancer patients who had one to three cancerous lymph nodes. Side effects of both chemotherapy regimens could be successfully controlled.
While the first study discussed at the ASCO meeting dealt with the type of chemotherapy, the second study involved the sequence of chemotherapy in relation to other treatments. In particular, researchers of the second study found that women who receive both chemotherapy and the drug tamoxifen after surgery benefit more from receiving the chemotherapy before tamoxifen therapy.
"Many women in the United States receive tamoxifen and chemotherapy together after surgery," said Kathy S. Albain, MD, Director of Breast Cancer Research and Co-Director of the Breast Care Center at Loyola University Cardinal Bernardin Cancer Center in Chicago, in an ASCO statement. "Our results show that it is best to wait until chemotherapy is finished before starting tamoxifen to obtain optimal benefit from the chemotherapy."
In the study, researchers compared three groups of breast cancer patients (a total of 1,477 women): those who received tamoxifen after chemotherapy, those who received tamoxifen and chemotherapy at the same time, and those who only received tamoxifen. After eight years of follow-up, Dr. Albain and her colleagues found that 67% of the women who received tamoxifen after chemotherapy had survived cancer-free, compared with 62% of patients who received the two treatments at the same time, and 55% of patients who only received tamoxifen.
According to William J. Gradishar, MD, who moderated a press conference on breast cancer treatment advances, these two studies are likely to affect the treatment of many breast cancer patients across the United States.