Background: Dose-dense therapies have had a major impact on reducing toxicity and improving outcomes in breast cancer. A combination of docetaxel plus cyclophosphamide (TC) every 3 weeks has emerged as a common chemotherapy regimen used for treatment of node-negative or lower-risk node-positive breast cancer. We tested whether it is feasible to deliver TC on a dose-dense schedule.

Patients and Methods: We enrolled women with early stage breast cancer on a single-arm phase II study of adjuvant dose-dense TC (ddTC) through a regional oncology network (WON). All women completed primary surgery; subsequent therapy with TC was deemed appropriate by the treating physician. Planned treatment was docetaxel 75 mg/m2 plus cyclophosphamide 600 mg/m2 every 2 weeks for 4 cycles with subcutaneous pegfilgrastim 6 mg administered 24-48 hours after the administration of each chemotherapy cycle. The primary endpoint was feasibility of administering therapy within 10 weeks. A Simon Optimal 2-Stage design was employed for the study design.

Results: Of 42 women enrolled, 41 were evaluable by prespecified criteria. Median age was 54 (28-73). Most subjects had node negative (73%) or hormone receptor positive (71%) tumors. Of the 41 subjects, 37 (90.2%) completed therapy within 10 weeks and 34 (83%) completed therapy at 8 weeks without dose modification. Rates of grade 2 neuropathy were similar to that reported previously (15%) and there were no cases of grade 3 or higher neuropathy. The rate of neutropenic fever was low (2.5%). Rash and plantar/palmar erythrodythesia were common and reached grade 3 in four subjects (9.8%).

Conclusion: Dose-dense TC is feasible with tolerability profiles similar to standard TC and a low likelihood of neutropenic fever. This study supports further clinical development of this 8-week adjuvant chemotherapy regimen.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-12-10.