Increased Dose Density Is Feasible: A Pilot Study of Adjuvant Epirubicin and Cyclophosphamide followed by Paclitaxel, at 10- or 11-Day Intervals with Filgrastim Support in Women with Breast Cancer

Abstract

Because Cancer and Leukemia Group B 9741 trial showed a benefit for every 14-day administration of chemotherapy compared with every 21-day treatment, we hypothesized that even greater dose density would be more effective. We conducted a pilot trial to assess the feasibility of dose-dense chemotherapy consisting of a standard regime at 10- to 11-day intervals in the adjuvant/neoadjuvant setting. A 2-day window was allowed for scheduling logistics. Thirty-nine women with early-stage breast carcinoma were accrued from April 2004 to October 2004. Median age was 47 years (range, 26-67 years). Patients received therapy with 100 mg/m(2) epirubicin and 600 mg/m(2) cyclophosphamide (EC) q 10 to 11 days for four cycles followed by 175 mg/m(2) paclitaxel q 10 to 11 days for four cycles, all with filgrastim support (300 microg s.c. daily) from day 2 to 24 h before the next treatment. Thirty-five (90%) patients completed all planned therapy. The median intertreatment interval was 10 days (range, 8-28 days). Cycles (80.7%) were delivered at no more than 10- to 11-day intervals. There were five dose reductions of 25% for grade 3 nonhematologic toxicity in five patients. Six (16%) patients developed febrile neutropenia defined as temperature >38 degrees C with absolute neutrophil count <1,000/microL. All febrile neutropenia was during therapy with EC. Other grade 3 toxicities included bone pain, hand and foot syndrome, neuropathy, mucositis, nausea, and vomiting. Therapy with EC for four cycles followed by paclitaxel for four cycles at 10- to 11-day intervals is feasible. The approximately 30% reduction in intertreatment interval compared with every 14-day treatment could increase the efficacy of adjuvant chemotherapy.