A pilot study of dose-dense adjuvant paclitaxel without growth factor support for women with early breast carcinoma

Granulocyte-colony stimulating factor (G-CSF) was used in CALGB 9741 to support dose-dense sequential chemotherapy with doxorubicin and cyclophosphamide (AC) followed by paclitaxel (P) (Citron et al. J Clin Oncol 21:1431-1439, 2003). However, myelosuppression is not known to be dose or schedule limiting for paclitaxel. We therefore conducted this trial to determine the need for routine G-CSF, using the pegylated product (pG-CSF), support during the paclitaxel component of dose-dense sequential chemotherapy in women with early stage breast carcinoma (BC).

Eligible patients received dose-dense chemotherapy consisting of four cycles of AC followed by four cycles of P at two week intervals. pG-CSF (Neulasta) was administered after each of four cycles of AC but was held after P. Planned enrollment was 59 pts.

Of the first 15 patients, nine completed therapy without delays due to neutropenia but 6 (40%) did not, leading to implementation of the pre-specified early termination rule. Overall, 85% of P doses were successfully delivered on time. The mean treatment delay for the entire group due to neutropenia was 0.75 days. There was no significant correlation between neutropenia and prior WBC, ANC, or concurrent treatment with trastuzumab. Pts with neutropenia tended to be younger (Mean age 43.5) and have a lower BSA (1.65 m(2)). There were no febrile episodes due to omission of pG-CSF.

When paclitaxel is administered in a dose-dense fashion without growth factor support brief treatment delays are common. Further study is needed to identify the minimal pG-CSF administration that will avoid treatment delays.