title: Survival in patients with non-metastatic breast cancer treated with adjuvant trastuzumab in clinical practice.
abstract: OBJECTIVE
  The NSABP Trial B-31 and NCCTG Trial N9831 (B-31/N9831 trials, Romond et al. in N Engl J Med 353:1673-84, 2005. doi:10.1056/NEJMoa052122; Perez et al. in J Clin Oncol 32:3744-52, 2014. doi:10.1200/JCO.2014.55.5730) established the efficacy of adjuvant trastuzumab for patients with HER2-positive early stage breast cancer. We aimed to estimate the overall survival (OS) and relapse-free survival (RFS) of HER2-positive non-metastatic breast cancer patients treated with adjuvant trastuzumab in a clinical practice setting in the United States.
  
  
  METHODS
  Adult women initiating adjuvant trastuzumab within 1 year of breast cancer surgery were identified in the health claims database of the US Department of Defense (01/2003-12/2012). OS and RFS unadjusted rates at 4 and 6 years after the first trastuzumab treatment following the breast cancer diagnosis were estimated from Kaplan-Meier analyses.
  
  
  RESULTS
  The study sample included 3188 women followed for a median of 3.3 years after trastuzumab initiation and treated continuously with trastuzumab for a median of 12 months. The OS rates (95 % confidence intervals) at 4 and 6 years were 90.0 % (88.6-91.2) and 87.1 (85.3-88.6), respectively. The corresponding RFS rates were 75.8 % (74.0-77.5) and 72.7 (70.7-74.7), respectively. The OS and RFS rates at 6 years reported in the B-31/N9831 trials were 89.8 and 81.4 %, respectively.
  
  
  CONCLUSIONS
  OS rates estimated in this study were in range with those estimated in the B-31/N9831 trials, while RFS rates were lower. However, patients in the B-31/N9831 trials were younger and possibly had fewer comorbidities than patients in the current study; these differences were not adjusted for in the crude OS and RFS analyses.
authors.affiliation: Washington Cancer Institute, MedStar Washington Hospital Center, 110 Irving Street, NW, Room C-2149, Washington, DC 20010-2975 USA.
authors.forename: Christopher M
authors.identifier: 0000-0002-3846-5052
authors.initials: CM
authors.lastname: Gallagher
authors.affiliation: Virginia Oncology Associates, Virginia Beach, VA USA.
authors.forename: Kenneth
authors.initials: K
authors.lastname: More
authors.affiliation: Genentech, Inc., South San Francisco, CA USA.
authors.forename: Anthony
authors.initials: A
authors.lastname: Masaquel
authors.affiliation: Genentech, Inc., South San Francisco, CA USA.
authors.forename: Tripthi
authors.initials: T
authors.lastname: Kamath
authors.affiliation: Analysis Group, Inc., Montreal, QC Canada.
authors.forename: Annie
authors.initials: A
authors.lastname: Guerin
authors.affiliation: Analysis Group, Inc., Montreal, QC Canada.
authors.forename: Raluca
authors.initials: R
authors.lastname: Ionescu-Ittu
authors.affiliation: Analysis Group, Inc., Montreal, QC Canada.
authors.forename: Roy
authors.initials: R
authors.lastname: Nitulescu
authors.affiliation: Analysis Group, Inc., Montreal, QC Canada.
authors.forename: Marjolaine
authors.initials: M
authors.lastname: Gauthier-Loiselle
authors.affiliation: Health ResearchTx, Trevose, VA USA.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Sicignano
authors.affiliation: Navy and Marine Corps Public Health Center, Portsmouth, VA USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Butts
authors.affiliation: Analysis Group, Inc., Boston, MA USA.
authors.forename: Eric Q
authors.initials: EQ
authors.lastname: Wu
authors.affiliation: Genentech, Inc., South San Francisco, CA USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Barnett
keywords: HER2-positive breast cancer; Overall survival; Relapse; Trastuzumab