Chemotherapy (CTX) treatment patterns for early-stage breast cancer (ESBC): Changing use of anthracyclines (A).

Abstract

1083 Background: Anthracyclines (A), given in sequence or combination, have been the mainstay of adjuvant CTX for ESBC. Recent molecular studies have questioned the value of A for ESBC. Trials for ESBC, presented primarily in 2005, have demonstrated similar or improved efficacy with non-anthracycline (NA) CTX. We sought to understand changing use of A for ESBC from 2000-2010 as reported in the population-based 9-county Greater Bay Area Cancer Registry (GBACR). Methods: Using the GBACR database, we recorded use of A or NA based CTX regimens in women with ESBC and no prior CTX from 2000-2010, and correlated type of CTX with tumor stage, receptor status, and age. We evaluated the use of A vs. NA (80% taxane-based) CTX from 2000-2005 and 2006-2010. Results: 16,476 patients (pts) met criteria for inclusion; 2,032 (12%) were excluded (missing information, or CTX not given). Pt characteristics were: median age 52 (range 21-94), stage I (25%), II (56%), and III (19%), 69% HR+. From 2000-2010, 83% received A; overall use of A decreased (87% to 57%), and use of NA increased (13% to 43%). The Table compares use of NA CTX during the two time periods by clinical variables. With short follow-up there was no difference in survival based on use of A vs. NACTX. Conclusions: Use of NA CTX significantly increased during 2006-2010; this trend was independent of age or receptor status and was more pronounced in earlier stage disease. The timing of this change correlated with the presentation of two phase III trials, emphasizing the impact of early data from phase III trials on treatment practice, and confirming results from a large claims database (Giordano). Potential outcome differences will be evaluated in NSABP-B49 and with longer follow-up of this cohort. This study was supported by the UCSF Cancer Registry and CPIC. [Table: see text]