title: Duration and toxicity of adjuvant trastuzumab in older patients with early-stage breast cancer: a population-based study.
abstract: OBJECTIVE
  Few data are available regarding adjuvant trastuzumab use in older women with early-stage breast cancer. We examined rates and predictors of adjuvant trastuzumab completion and cardiac events in this population.
  
  
  METHODS
  We used Surveillance, Epidemiology, and End Results (SEER)-Medicare data to identify patients age ≥ 66 years with stage I to III breast cancer diagnosed between 2005 and 2009 who received trastuzumab. Completion of trastuzumab was defined as receipt of more than 270 days of therapy. We used multivariable logistic regression to examine patient, clinical, and geographic characteristics associated with trastuzumab completion. We also examined rates of hospital admissions for cardiac events.
  
  
  RESULTS
  Among 2,028 women, most (71.2%) were younger than age 76 years and had a comorbidity score of 0 (66.8%); 85.2% received trastuzumab with chemotherapy. Overall, 1,656 women (81.7%) completed trastuzumab. Older patients and those with more comorbidity had lower odds of treatment completion (odds ratio [OR], 0.40 [95% CI, 0.30 to 0.55] for age ≥ 80 years v age 66 to 70 years; OR, 0.65 [95% CI, 0.49 to 0.88] for comorbidity score of 2 v 0). During treatment, 73 patients (3.6%) were hospitalized for cardiac events (2.6% of those who completed trastuzumab v 8.1% of those who did not; P < .001).
  
  
  CONCLUSIONS
  Most older patients who initiated adjuvant trastuzumab completed therapy. Age and comorbidity were among factors that were associated with treatment completion, and rates of significant cardiac events were higher in those who did not complete therapy. Further exploration of toxicities and optimal treatments for older women with human epidermal growth factor receptor 2-positive breast cancer are warranted.
authors: Ines Vaz-Luis, Nancy U. Lin, Eric P. Winer, and Rachel A. Freedman, Dana-Farber Cancer Institute; Nancy L. Keating, Harvard Medical School; Nancy L. Keating and Huichuan Lii, Brigham and Women's Hospital, Boston, MA; and Ines Vaz-Luis, Instituto de Medicina Molecular, Lisbon, Portugal.
authors: Ines
authors: I
authors: Vaz-Luis
authors: Nancy L
authors: NL
authors: Keating
authors: Nancy U
authors: NU
authors: Lin
authors: Huichuan
authors: H
authors: Lii
authors: Eric P
authors: EP
authors: Winer
authors: Rachel A
authors: RA
authors: Freedman
mesh_terms: D000368:Aged; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage* / Q000009:adverse effects*; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000009:adverse effects*; D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000601:surgery*; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D016015:Logistic Models; D006278:Medicare; D015999:Multivariate Analysis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis*; D018426:SEER Program; D000068878:Trastuzumab; D014481:United States / Q000453:epidemiology
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab; C508053:ERBB2 protein, human