PROVIDENCE, RIWeekly, high-dose neoadjuvant chemother-apy
with paclitaxel (Taxol) resulted in an 87% clinical response rate in
a small pilot study aimed at assessing the feasibility and
tolerability of the regimen in patients with stage IIB-IIIB breast cancer.
Among 38 patients who received six weekly 175 mg/m² doses of
paclitaxel (one or two 8-week cycles) before surgery, 11 had a
complete remission and 22, a partial remission. Five additional
patients had stable disease, and only one patient had progressive
disease, William Sikov, MD, reported at the San Antonio Breast Cancer Symposium.
The impressive thing about this particular regimen was the
rapidity with which patients responded, Dr. Sikov, of Brown
University, said at a poster session. A majority of the
patients went to surgery after just one cycle of therapy. Many
different types of neoadjuvant chemotherapy have produced fairly high
response rates, but I think our response rate of 87% is on the high
end, even among other very active regimens.
Multiple factors contribute to the rationale for the weekly
paclitaxel regimen, he said. Paclitaxel is one of the most active
single agents in advanced breast cancer. In theory, weekly dosing
should result in maintenance of tissue levels, afford more
opportunity for dose escalation, and possibly lead to enhancement of
paclitaxels apoptotic and antiangiogenic properties.
Additionally, use of single-agent paclitaxel in the neoadjuvant
setting saves the doxorubicin-cyclophosphamide combination for
The trial included 39 patients, whose median age was 49 years. Ten of
the patients were older than 60. The cohort included 14 patients with
stage IIB disease, 7 with stage IIIA cancer, and 18 with stage IIIB
disease, including 11 who had inflammatory breast cancer.
A single cycle of therapy was given to 24 patients, and the remaining
14 evaluable patients had two cycles of treatment. We tried to
give a second cycle of therapy to patients who had large tumors and
those who had inflammatory breast cancer, Dr. Sikov said.
We saw very clear evidence that some patients continued to
respond into the second cycle.
The median dose delivered was 131 mg/m²/wk. Dose modification
was most often due to development of neutropenia, particularly during
weeks 3 and 6. Overall, 86% of the patients developed grade 3-4
neutropenia. Five patients required dose modifications because of
neurologic toxicity. Only one patient discontinued therapy because of toxicity.
Clinical responses included 3 complete responses (CRs) and 10 partial
responses (PRs) in patients who had stage IIB cancer and 8 CRs and 12
PRs in patients with stages IIIA-B cancer. Among the stage IIIB
patients with inflammatory breast cancer, there were 4 CRs and 4 PRs.
The paclitaxel regimen resulted in seven pathologic complete
responses. Nine other patients had residual disease of 2 cm or less,
12 had residual disease of 2 to 5 cm, and seven had residual disease
that exceeded 5 cm.
The pathologic complete response rate was not quite what we had
hoped for, Dr. Sikov said, but a 20% pathologic complete
response rate is at least as good as is seen with other neo-adjuvant