The addition of the anticancer drug paclitaxel
(Taxol) to standard chemotherapy may increase the chances of a cure
for women with breast cancer.
A breast cancer trial headed by the Cancer and Leukemia Group B
(CALGB) demonstrated that administering paclitaxel in addition to a
standard chemotherapy regimen improved survival by 26% and reduced
the risk of cancer recurrence by 22% when compared to the previous
standard treatment regimen. These results were recently released by
an independent monitoring committee and presented at the 34th annual
meeting of the American Society of Clinical Oncology in Los Angeles.
"This represents the single most significant advance in the
treatment of early-stage breast cancer in the past 20 years since the
introduction of doxorubicin," said Richard L. Schilsky,MD,
director, University of Chicago Cancer Research Center, professor of
medicine, University of Chicago, and chairman, CALGB. "This new
combination therapy has the potential to save tens of thousands of
lives worldwide each year." There has not been a similar advance
in adjuvant breast cancer therapy since the 1970s, when researchers
discovered that postoperative combination chemotherapy substantially
improved breast cancer survival compared to surgery alone.
"The results of this study are very dramatic. These data clearly
demonstrate that we are substantially improving a womans
chances for remaining free of her breast cancer by adding paclitaxel
sequentially to the standard regimen of doxorubicin and
cyclophosphamide," said Larry Norton, MD, head, Division of
Solid Tumor Oncology, Memorial Sloan-Kettering Cancer Center.
"Because it significantly improves survival, this regimen
represents a new standard for patients with breast cancer."
Additional Follow-up Planned
"The significant increase in overall survival and reduction in
recurrence at this early stage of the trial is extremely
promising," he said. "Although the results are early,
experience from other breast cancer adjuvant trials suggest that the
early benefit will be maintained with continued follow-up." The
CALGB will continue to monitor the progress of those enrolled in the
trial for at least 10 years.
Of the 183,000 women newly diagnosed with breast cancer each year in
the United States, approximately 75,500 are candidates for adjuvant
therapy. "If we can decrease the risk of death among this large
patient population by 26%, the implications will be staggering,"
said I. Craig Henderson, md, who was the principal investigator of
the trial, which involved over 3,000 women.
"This regimen offers more women a chance for cure," said
Largest Completed Study of Paclitaxel
This phase III, adjuvant trial, headed by the CALGB, was designed to
compare doxorubicin plus cyclophosphamide to the same regimen
followed by paclitaxel in women with breast cancer involving the
lymph nodes under the arm. Sequential use was based on a mathematical
analysis of breast cancer biology.
The trial involved more than 3,000 women and is the largest study
ever completed with paclitaxel. Other cancer cooperative study groups
involved in this study were the Eastern Cooperative Oncology Group,
Southwest Oncology Group, and North Central Cancer Treatment Group,
which are all sponsored and supported by the National Cancer
Institute. In all, several hundred institutions participated in this study.
"These new data further the importance of screening and early
breast cancer detection through consistent self-examination by all
adult women. The more women we diagnose early, the more women will
benefit from this important new treatment advance," said Dr. Henderson.