Current patterns of chemotherapy and supportive care for early-stage breast cancer (ESBC).

Abstract

1062 Background: ESBC is commonly treated with myelosuppressive chemotherapy, and high relative dose intensity (RDI) correlates with improved overall survival. A retrospective analysis of patients with ESBC treated from 1997–2000 showed that 56% received an RDI < 85% (Lyman et al. JCO. 2003;21:4524-4531). To determine current practice, we evaluated ESBC treatment patterns at 24 US community- and hospital-based oncology practices. Methods: Data were abstracted from medical records of 532 patients with ESBC treated from January 2007–December 2009. Inclusion criteria included surgically resected ESBC (stage I-IIIA); ≥ 18 years old; and completion of at least 1 standard chemotherapy cycle on an every 2 or 3 week schedule. The primary endpoint was RDI over planned cycles. Other endpoints were incidence of dose delays ≥ 7 days, dose reductions ≥ 15% from standard, grade 3/4 neutropenia (SN), febrile neutropenia (FN), FN-related hospitalization, granulocyte-colony stimulating factor (G-CSF) use, and antimicrobial therapy. Descriptive statistics were generated for all endpoints. Results: In this study, mean (range) age was 55 (29–85) years. Relative to previously published results, chemotherapy regimens have shifted from mainly doxorubicin + cyclophosphamide (AC) (previously 35%) to docetaxel + cyclophosphamide (TC; n = 221; 42%) and AC followed by paclitaxel (AC-T; n = 163; 31%). Mean RDI is now higher (93% for both TC and the most common AC-T schedule [dose dense AC-T; n = 84] vs 79% previously); the incidence of dose delays (16% vs 25% previously) and dose reductions (21% vs 37% previously) have decreased; and primary prophylactic use of G-CSF has increased (76% vs 3% previously). In this study, 40% of patients had SN, 3% had FN, 2% had an FN-related hospitalization, and 30% received antimicrobial therapy. These measures were not available in the previously published results. Conclusions: The observed changes between the two studies are noteworthy though inferential comparisons are limited by changes in treatments and other factors. RDI has improved over time, but 16% of patients in this study received an RDI < 85%. Further evaluation is needed to identify factors associated with lower RDI and determine outcomes for these patients.