title: Pathological complete response and prognosis after neoadjuvant chemotherapy for HER2-positive breast cancers before and after trastuzumab era: results from a real-life cohort.
abstract: Trastuzumab was introduced a decade ago and has improved outcomes for HER2-positive breast cancer. We investigated the factors predictive of pathological complete response (pCR), prognostic factors for disease-free survival (DFS), and interactions between pCR and DFS after neoadjuvant treatment.
  
  
  
  We identified 287 patients with primary HER2-positive breast cancers given neoadjuvant chemotherapy (NAC) between 2002 and 2011. Univariate and multivariate analyses of clinical and pathological factors associated with pCR and DFS were performed.
  
  
  
  pCR rates differed between patients receiving neoadjuvant trastuzumab treatment or not (47.7% versus 19.3%, P<0.0001). DFS also differed significantly between patients receiving adjuvant trastuzumab or not (hazard ratio=4.84, 95% CI (2.52; 9.31), P<0.001). We analysed 199 patients given neoadjuvant and adjuvant trastuzumab. Multivariate analysis identified older age and hormone receptor-negative tumours as independent predictors of pCR. T stage (hazard ratio=2.55, 95% CI (1.01; 6.48), P=0.05) and strict pCR (hazard ratio=9.15, 95% CI (1.22; 68.83), P=0.03) were independent predictors of DFS. The latter association was significant in the HR-negative subgroup (P=0.02) but not in the HR-positive subgroup (P=0.12).
  
  
  
  Major pCR and DFS gains in HER2-positive BC were observed since 'trastuzumab' era. Further improvements rely on the enrollment of accurately selected patients into clinical trials.
authors.affiliation: Institut Curie, PSL Research University, Translational Research Department, INSERM, U932 Immunity and Cancer, Residual Tumor & Response to Treatment Laboratory (RT2Lab), F-75248, Paris, France.
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Hamy
authors.affiliation: Biostatistics Department, Institut Curie, Paris 75005, France.
authors.forename: Lisa
authors.initials: L
authors.lastname: Belin
authors.affiliation: Institut Curie, PSL Research University, Translational Research Department, INSERM, U932 Immunity and Cancer, Residual Tumor & Response to Treatment Laboratory (RT2Lab), F-75248, Paris, France.|Department of Surgery, Institut Curie, Paris F-75248, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Bonsang-Kitzis
authors.affiliation: Department of Surgery, Institut Curie, Paris F-75248, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Paquet
authors.affiliation: Department of Medical Oncology, Institut Curie, Paris, France.
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Pierga
authors.affiliation: Department of Medical Oncology, Institut Curie, Paris, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Lerebours
authors.affiliation: Department of Medical Oncology, Institut Curie, Paris, France.
authors.forename: Paul
authors.initials: P
authors.lastname: Cottu
authors.affiliation: Department of Surgery, Institut Curie, Paris F-75248, France.
authors.forename: Roman
authors.initials: R
authors.lastname: Rouzier
authors.affiliation: Biostatistics Department, Institut Curie, Paris 75005, France.
authors.forename: Alexia
authors.initials: A
authors.lastname: Savignoni
authors.affiliation: Department of Tumor Biology, Institut Curie, Paris 75005, France.
authors.forename: Marick
authors.initials: M
authors.lastname: Lae
authors.affiliation: Institut Curie, PSL Research University, Translational Research Department, INSERM, U932 Immunity and Cancer, Residual Tumor & Response to Treatment Laboratory (RT2Lab), F-75248, Paris, France.|Department of Surgery, Institut Curie, Paris F-75248, France.
authors.forename: Fabien
authors.initials: F
authors.lastname: Reyal
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000737:chemistry / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D015331:Cohort Studies; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis*; D000068878:Trastuzumab / Q000627:therapeutic use*
chemical_list: D000970:Antineoplastic Agents; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab; C508053:ERBB2 protein, human