title: Effect of age on breast cancer outcomes in women with human epidermal growth factor receptor 2-positive breast cancer: results from a herceptin adjuvant trial.
abstract: OBJECTIVE
  Previous research has suggested that young age at diagnosis is an independent risk factor for breast cancer recurrence and death. No prior studies have adequately controlled for human epidermal growth factor receptor 2 (HER2) status or anti-HER2 treatment. We sought to evaluate whether age was a prognostic or predictive factor in the HERA trial.
  
  
  METHODS
  We used 2-year median follow-up data and dichotomized age at 40 years to evaluate its prognostic effect on outcomes for women assigned to trastuzumab for 1 year or observation.
  
  
  RESULTS
  Of the 1,703 women randomly assigned to 1 year of trastuzumab and 1,698 to observation, 722 (21%) were age ≤ 40 years at study entry. In separate Cox models, controlling for relevant prognostic and predictive factors, disease-free (DFS) and overall survival (OS) hazard ratios (HRs) were consistent for women age ≤ 40 versus > 40 years, regardless of treatment assignment (observation group: DFS HR age ≤ 40 v > 40 years, 1.18; 95% CI, 0.90 to 1.54; OS HR age ≤ 40 v > 40 years, 1.01; 95% CI, 0.60 to 1.69; trastuzumab group: DFS HR age ≤ 40 v > 40 years, 1.11; 95% CI, 0.81 to 1.51; OS HR age ≤ 40 v > 40 years, 1.18; 95% CI, 0.66 to 2.09). Interaction between age group and treatment effect was not statistically significant (DFS P = .89; OS P = .55).
  
  
  CONCLUSIONS
  In a retrospective analysis of a large randomized controlled trial of women with early-stage HER2-positive breast cancer, age was not strongly associated with risk of early recurrence or prediction of benefit from trastuzumab therapy. Future research should investigate whether age is a predictor of later recurrence and evaluate the impact of age within groups with other tumor subtypes.
authors.affiliation: Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA 02115, USA. ahpartridge@partners.org
authors.forename: Ann H
authors.initials: AH
authors.lastname: Partridge
authors.forename: Shari
authors.initials: S
authors.lastname: Gelber
authors.forename: Martine J
authors.initials: MJ
authors.lastname: Piccart-Gebhart
authors.forename: Florine
authors.initials: F
authors.lastname: Focant
authors.forename: Matthew
authors.initials: M
authors.lastname: Scullion
authors.forename: Eileen
authors.initials: E
authors.lastname: Holmes
authors.forename: Eric P
authors.initials: EP
authors.lastname: Winer
authors.forename: Richard D
authors.initials: RD
authors.lastname: Gelber
mesh_terms: D000328:Adult; D000367:Age Factors; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000201:enzymology* / Q000473:pathology; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D016016:Proportional Hazards Models; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D012189:Retrospective Studies; D000068878:Trastuzumab; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab; C508053:ERBB2 protein, human