HOUSTONWeekly paclitaxel (Taxol) as part of a primary systemic
chemotherapy regimen for operable breast cancer improves pathologic complete
remission rates when compared with every 3-week paclitaxel therapy,
according to results of a prospective phase III trial (ASCO abstract 135).
"When you administer paclitaxel weekly, pathologic complete response
is double that of the usual protocol in which it is given every 3
weeks," said lead author Marjorie C. Green, MD, assistant professor of
breast medical oncology at the University of Texas MD Anderson Cancer Center
in Houston. "If we believe that pathologic complete response translates
into improved survival based upon the results of studies such as B18, then
the data are very exciting for our patients. The weekly regimen may be
better but those results should be validated," she told ONI.
Paclitaxel has significant antitumor activity in patients with metastatic
breast cancer who have been previously treated with or exposed to
anthracycline-containing chemotherapy. Although pathologic complete
response, defined as the absence of invasive cancer in the breast and lymph
nodes, portends a good prognosis following treatment, correlation with
survival and clinical outcome is still incomplete.
Randomized by Nodal Status
Previous studies suggest that patients who achieve a pathologic complete
response after primary systemic chemotherapy have better survival than do
similarly staged patients who have residual disease following primary
To determine if different schedules or dose densities of paclitaxel
improve pathologic complete response rates or reduce toxicity, 258 patients
with operable noninflammatory breast cancer (T1-3, N0-1, M0) were randomized
by nodal status to receive either weekly or every-3-week regimens of
paclitaxel as primary systemic chemotherapy.
Subsequently, all patients received combination therapy with FAC
(fluorouracil/doxorubicin [Adriamycin]/cyclophosphamide [Cytoxan, Neosar]
every 3 weeks for four cycles, followed by locoregional and hormonal therapy
as appropriate. Patient groups were generally well balanced in terms of
demographic and clinical variables including tumor size.