title: Incidence of heart failure or cardiomyopathy after adjuvant trastuzumab therapy for breast cancer.
abstract: OBJECTIVE
  The purpose of this study was to estimate heart failure (HF) and cardiomyopathy (CM) rates after adjuvant trastuzumab therapy and chemotherapy in a population of older women with early-stage breast cancer.
  
  
  BACKGROUND
  Newer biologic therapies for breast cancer such as trastuzumab have been reported to increase HF and CM in clinical trials, especially in combination with anthracycline chemotherapy. Elderly patients, however, typically have a higher prevalence of cardiovascular risk factors and have been underrepresented in trastuzumab clinical trials.
  
  
  METHODS
  Using Surveillance, Epidemiology, and End Results-Medicare data from 2000 through 2007, we identified women 67 to 94 years of age with early-stage breast cancer. We calculated 3-year incidence rates of HF or CM for the following mutually exclusive treatment groups: trastuzumab (with or without nonanthracycline chemotherapy), anthracycline plus trastuzumab, anthracycline (without trastuzumab and with or without nonanthracycline chemotherapy), other nonanthracycline chemotherapy, or no adjuvant chemotherapy or trastuzumab therapy. HF or CM events were ascertained from administrative Medicare claims. Poisson regression was used to quantify risk of HF or CM, adjusting for sociodemographic factors, cancer characteristics, and cardiovascular conditions.
  
  
  RESULTS
  We identified 45,537 older women (mean age: 76.2 years, standard deviation: 6.2 years) with early-stage breast cancer. Adjusted 3-year HF or CM incidence rates were higher for patients receiving trastuzumab (32.1 per 100 patients) and anthracycline plus trastuzumab (41.9 per 100 patients) compared with no adjuvant therapy (18.1 per 100 patients, p < 0.001). Adding trastuzumab to anthracycline therapy added 12.1, 17.9, and 21.7 HF or CM events per 100 patients over 1, 2, and 3 years of follow-up, respectively.
  
  
  CONCLUSIONS
  HF or CM are common complications after trastuzumab therapy for older women, with higher rates than those reported from clinical trials.
authors.affiliation: Section of Cardiovascular Medicine, Department of Medicine, Yale University School of Medicine, New Haven, CT 06520, USA. jersey.chen@yale.edu
authors.forename: Jersey
authors.initials: J
authors.lastname: Chen
authors.forename: Jessica B
authors.initials: JB
authors.lastname: Long
authors.forename: Arti
authors.initials: A
authors.lastname: Hurria
authors.forename: Cynthia
authors.initials: C
authors.lastname: Owusu
authors.forename: Richard M
authors.initials: RM
authors.lastname: Steingart
authors.forename: Cary P
authors.initials: CP
authors.lastname: Gross
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D061067:Antibodies, Monoclonal, Humanized / Q000009:adverse effects*; D000970:Antineoplastic Agents / Q000009:adverse effects*; D001943:Breast Neoplasms / Q000188:drug therapy*; D009202:Cardiomyopathies / Q000139:chemically induced* / Q000453:epidemiology; D005260:Female; D006333:Heart Failure / Q000139:chemically induced* / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D018426:SEER Program; D000068878:Trastuzumab
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D000068878:Trastuzumab