title: Estimating the magnitude of trastuzumab effects within patient subgroups in the HERA trial.
abstract: BACKGROUND
  Trastuzumab (Herceptin(R)) improves disease-free survival (DFS) and overall survival for patients with human epidermal growth factor receptor 2 (HER2)-positive early breast cancer. We aimed to assess the magnitude of its clinical benefit for subpopulations defined by nodal and steroid hormone receptor status using data from the Herceptin Adjuvant (HERA) study.
  
  
  METHODS
  HERA is an international multicenter randomized trial comparing 1 or 2 years of trastuzumab treatment with observation after standard chemotherapy in women with HER2-positive breast cancer. In total, 1703 women randomized to 1-year trastuzumab and 1698 women randomized to observation were included in these analyses. Median follow-up was 23.5 months. The primary endpoint was DFS.
  
  
  RESULTS
  The overall hazard ratio (HR) for trastuzumab versus observation was 0.64 [95% confidence interval (CI) 0.54-0.76; P < 0.0001], ranging from 0.46 to 0.82 for subgroups. Estimated improvement in 3-year DFS in subgroups ranged from +11.3% to +0.6%. Patients with the best prognosis (those with node-negative disease and tumors 1.1-2.0 cm) had benefit similar to the overall cohort (HR 0.53, 95% CI 0.26-1.07; 3-year DFS improvement +4.6%, 95% CI -4.0% to 13.2%).
  
  
  CONCLUSIONS
  Adjuvant trastuzumab therapy reduces the risk of relapse similarly across subgroups defined by nodal status and steroid hormone receptor status, even those at relatively low risk for relapse.
authors.affiliation: Helios Klinikum Berlin Buch, Academic Hospital of the University Charite Berlin, Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Untch
authors.forename: R D
authors.initials: RD
authors.lastname: Gelber
authors.forename: C
authors.initials: C
authors.lastname: Jackisch
authors.forename: M
authors.initials: M
authors.lastname: Procter
authors.forename: J
authors.initials: J
authors.lastname: Baselga
authors.forename: R
authors.initials: R
authors.lastname: Bell
authors.forename: D
authors.initials: D
authors.lastname: Cameron
authors.forename: M
authors.initials: M
authors.lastname: Bari
authors.forename: I
authors.initials: I
authors.lastname: Smith
authors.forename: B
authors.initials: B
authors.lastname: Leyland-Jones
authors.forename: E
authors.initials: E
authors.lastname: de Azambuja
authors.forename: P
authors.initials: P
authors.lastname: Wermuth
authors.forename: R
authors.initials: R
authors.lastname: Khasanov
authors.forename: F
authors.initials: F
authors.lastname: Feng-Yi
authors.forename: C
authors.initials: C
authors.lastname: Constantin
authors.forename: J I
authors.initials: JI
authors.lastname: Mayordomo
authors.forename: C-H
authors.initials: CH
authors.lastname: Su
authors.forename: S-Y
authors.initials: SY
authors.lastname: Yu
authors.forename: A
authors.initials: A
authors.lastname: Lluch
authors.forename: E
authors.initials: E
authors.lastname: Senkus-Konefka
authors.forename: C
authors.initials: C
authors.lastname: Price
authors.forename: F
authors.initials: F
authors.lastname: Haslbauer
authors.forename: T
authors.initials: T
authors.lastname: Suarez Sahui
authors.forename: V
authors.initials: V
authors.lastname: Srimuninnimit
authors.forename: M
authors.initials: M
authors.lastname: Colleoni
authors.forename: A S
authors.initials: AS
authors.lastname: Coates
authors.forename: M J
authors.initials: MJ
authors.lastname: Piccart-Gebhart
authors.forename: A
authors.initials: A
authors.lastname: Goldhirsch
mesh_terms: D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D005260:Female; D006801:Humans; D038622:Internationality; D008207:Lymphatic Metastasis; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D016019:Survival Analysis; D000068878:Trastuzumab
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D000068878:Trastuzumab