HOUSTONWeekly paclitaxel(Drug information on 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 systemic chemotherapy.
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.