A retrospective evaluation of chemotherapy dose intensity and supportive care for early-stage breast cancer in a curative setting.

Early-stage breast cancer (ESBC) is commonly treated with myelosuppressive chemotherapy, and maintaining full-dose chemotherapy on the planned schedule is associated with improved patient outcome. Retrospective analysis of patients with ESBC treated from 1997 to 2000 showed that 56 % of patients received a relative dose intensity (RDI) <85 % (Lyman et al., J Clin Oncol 21(24):4524-4531, 2003). To determine current practice, we evaluated treatment patterns at 24 US community- and hospital-based oncology practices, 79 % of which participated in the previous study. Data were abstracted from medical records of 532 patients with surgically resected ESBC (stage I-IIIa) treated from 2007 to 2009, who were ≥18 years old and had completed ≥1 cycle of one of the following regimens: docetaxel + cyclophosphamide (TC); doxorubicin + cyclophosphamide (AC); AC followed by paclitaxel (AC-T); docetaxel + carboplatin + trastuzumab (TCH); or docetaxel + doxorubicin + cyclophosphamide (TAC). Endpoints included RDI, dose delays, dose reductions, grade 3/4 neutropenia, febrile neutropenia (FN), FN-related hospitalization, granulocyte colony-stimulating factor (G-CSF) use, and antimicrobial use. In this study, TC was the most common chemotherapy regimen (42 %), and taxane-based chemotherapy regimens were more common relative to the previously published results (89 vs <4 %). Overall, 83.8 % of patients received an RDI ≥85 %, an improvement over the previous study where 44.5 % received an RDI ≥85 %. Other changes seen between this and the previous study included a lower incidence of dose delays (16 vs 25 %) and dose reductions (21 vs 37 %) and increased use of primary prophylactic G-CSF (76 vs ~3 %). Here, 40 % of patients had grade 3/4 neutropenia, 3 % had FN, 2 % had an FN-related hospitalization, and 30 % received antimicrobial therapy; these measures were not available in the previously published results. Though RDI was higher here than in the previous study, 16.2 % of patients still received an RDI <85 %. Understanding factors that contribute to reduced RDI may further improve chemotherapy delivery, and ultimately, patient outcomes.

Duke Scholars

Author Gary Herbert Lyman Medicine, Medical Oncology

Author Jeffrey Crawford Medicine, Medical Oncology