A new study suggests that paclitaxel, originally derived from the Pacific yew tree, may improve survival in women with breast cancer.
Taxanes are compounds produced by plants in the genus Taxus, such as the Pacific yew tree. Researchers from Eastern Cooperative Oncology Group in Philadelphia, PA, compared the efficacy of two different taxanes, docetaxel and paclitaxel, given either weekly or every three weeks, in the adjuvant treatment of breast cancer.
Paclitaxel is isolated from the bark of the Pacific yew tree (Taxus brevifolia) and is available under the brand name Taxol®. As early as 1971, paclitaxel was used as an anti-tumor drug in clinical trials run by the U.S. National Cancer Institute. Taxol® has succeeded in treating advanced ovarian and breast cancers in clinical trials.
Paclitaxel is now approved by the U.S. Food and Drug Administration (FDA) and is hailed as one of the most significant advances in cancer chemotherapy in recent history.
In the study, 4,950 women with axillary lymph node-positive or high-risk lymph node-negative breast cancer first received four cycles of intravenous doxorubicin and cyclophosphamide at three-week intervals and were then assigned to paclitaxel or docetaxel, given intravenously at either three-week intervals for four cycles, or at one-week intervals for 12 cycles. The primary end point was disease-free survival.
Compared to patients receiving the standard therapy of paclitaxel every three weeks, the odds ratio for disease-free survival was 1.27 among those receiving weekly paclitaxel, 1.23 among those receiving docetaxel every three weeks and 1.09 among those receiving weekly docetaxel.
As compared with standard therapy, the study found that weekly paclitaxel was associated with improved survival. In a subgroup of patients whose tumors expressed no human epidermal growth factor receptor type 2 protein, an exploratory analysis found similar improvements in disease-free and overall survival with weekly paclitaxel treatment regardless of hormone-receptor expression. Grade 2, 3 or 4 neuropathy (nerve pain) was more frequent with weekly paclitaxel than with paclitaxel every three weeks (27 percent vs. 20 percent).
The study authors concluded that weekly paclitaxel after standard adjuvant chemotherapy may improve disease-free and overall survival in women with breast cancer.
Susan G. Komen for the Cure® will be hosting its National Race for the Cure® 5K Walk/Run on Saturday, June 7, 2008 in Washington, DC, on the National Mall. For more information on this race, please click here. Komen has dedicated nearly $1 billion to creating awareness and finding a cure for breast cancer, making it the nation's largest private funding source for breast health and breast cancer.