title: Real-Life Use and Effectiveness of Adjuvant Trastuzumab in Early Breast Cancer Patients: A Study of the Southeast Netherlands Breast Cancer Consortium.
abstract: BACKGROUND
  The impact of drug prescriptions in real life as opposed to strict clinical trial prescription is only rarely assessed, although it is well recognized that incorrect use may harm patients and may have a significant impact on health care resources. We investigated the use and effectiveness of adjuvant trastuzumab in daily practice compared with the effectiveness in clinical trials.
  
  
  METHODS
  We included all patients with stage I-III invasive breast cancer, irrespective of human epidermal growth factor receptor 2 (HER2) status, diagnosed in five hospitals in the southeast of The Netherlands in 2005-2007. We aimed to assess the actual use of adjuvant trastuzumab in early HER2-positive breast and its efficacy in daily practice.
  
  
  RESULTS
  Of 2,684 patients included, 476 (17.7%) had a HER2-positive tumor. Of these, 251 (52.7%) patients had an indication for trastuzumab treatment of which 196 (78.1%) patients actually received it. Of the 225 patients without an indication, 34 (15.1%) received trastuzumab. Five-year disease-free survival was 80.7% for (n = 230) patients treated with versus 68.2% for (n = 246) patients not treated with trastuzumab (p = .0023), and 5-year overall survival rates were 90.7% and 77.4%, respectively (p = .0002). The hazard ratio for disease recurrence was 0.63 (95% confidence interval, 0.37-1.06) for trastuzumab when adjusting for potential confounders.
  
  
  CONCLUSIONS
  This study shows that in real life, patients treated with trastuzumab in early-stage HER2-positive breast cancer had a 5-year disease-free and overall survival comparable to prior randomized trials. For informative decision making, real-life data are of additional value, providing insight on outcome of patients considered ineligible for treatment.
authors.affiliation: Departments of Medical Oncology, Pathology, Clinical Epidemiology and Medical Technology Assessment, and Epidemiology and GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands; Department of Internal Medicine, Máxima Medical Centre, Veldhoven, The Netherlands; Department of Internal Medicine, Atrium Medical Centre Parkstad, Heerlen, The Netherlands; Department of Internal Medicine, Orbis Medical Centre, Sittard, The Netherlands; Department of Internal Medicine, VieCuri Medical Centre, Venlo, The Netherlands; Biostatistics, Department for Health Evidence, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Shanly C
authors.initials: SC
authors.lastname: Seferina
authors.affiliation: Departments of Medical Oncology, Pathology, Clinical Epidemiology and Medical Technology Assessment, and Epidemiology and GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands; Department of Internal Medicine, Máxima Medical Centre, Veldhoven, The Netherlands; Department of Internal Medicine, Atrium Medical Centre Parkstad, Heerlen, The Netherlands; Department of Internal Medicine, Orbis Medical Centre, Sittard, The Netherlands; Department of Internal Medicine, VieCuri Medical Centre, Venlo, The Netherlands; Biostatistics, Department for Health Evidence, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Dorien J A
authors.initials: DJ
authors.lastname: Lobbezoo
authors.affiliation: Departments of Medical Oncology, Pathology, Clinical Epidemiology and Medical Technology Assessment, and Epidemiology and GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands; Department of Internal Medicine, Máxima Medical Centre, Veldhoven, The Netherlands; Department of Internal Medicine, Atrium Medical Centre Parkstad, Heerlen, The Netherlands; Department of Internal Medicine, Orbis Medical Centre, Sittard, The Netherlands; Department of Internal Medicine, VieCuri Medical Centre, Venlo, The Netherlands; Biostatistics, Department for Health Evidence, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Maaike
authors.initials: M
authors.lastname: de Boer
authors.affiliation: Departments of Medical Oncology, Pathology, Clinical Epidemiology and Medical Technology Assessment, and Epidemiology and GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands; Department of Internal Medicine, Máxima Medical Centre, Veldhoven, The Netherlands; Department of Internal Medicine, Atrium Medical Centre Parkstad, Heerlen, The Netherlands; Department of Internal Medicine, Orbis Medical Centre, Sittard, The Netherlands; Department of Internal Medicine, VieCuri Medical Centre, Venlo, The Netherlands; Biostatistics, Department for Health Evidence, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: M Wouter
authors.initials: MW
authors.lastname: Dercksen
authors.affiliation: Departments of Medical Oncology, Pathology, Clinical Epidemiology and Medical Technology Assessment, and Epidemiology and GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands; Department of Internal Medicine, Máxima Medical Centre, Veldhoven, The Netherlands; Department of Internal Medicine, Atrium Medical Centre Parkstad, Heerlen, The Netherlands; Department of Internal Medicine, Orbis Medical Centre, Sittard, The Netherlands; Department of Internal Medicine, VieCuri Medical Centre, Venlo, The Netherlands; Biostatistics, Department for Health Evidence, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Franchette
authors.initials: F
authors.lastname: van den Berkmortel
authors.affiliation: Departments of Medical Oncology, Pathology, Clinical Epidemiology and Medical Technology Assessment, and Epidemiology and GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands; Department of Internal Medicine, Máxima Medical Centre, Veldhoven, The Netherlands; Department of Internal Medicine, Atrium Medical Centre Parkstad, Heerlen, The Netherlands; Department of Internal Medicine, Orbis Medical Centre, Sittard, The Netherlands; Department of Internal Medicine, VieCuri Medical Centre, Venlo, The Netherlands; Biostatistics, Department for Health Evidence, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Roel J W
authors.initials: RJ
authors.lastname: van Kampen
authors.affiliation: Departments of Medical Oncology, Pathology, Clinical Epidemiology and Medical Technology Assessment, and Epidemiology and GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands; Department of Internal Medicine, Máxima Medical Centre, Veldhoven, The Netherlands; Department of Internal Medicine, Atrium Medical Centre Parkstad, Heerlen, The Netherlands; Department of Internal Medicine, Orbis Medical Centre, Sittard, The Netherlands; Department of Internal Medicine, VieCuri Medical Centre, Venlo, The Netherlands; Biostatistics, Department for Health Evidence, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Agnès J
authors.initials: AJ
authors.lastname: van de Wouw
authors.affiliation: Departments of Medical Oncology, Pathology, Clinical Epidemiology and Medical Technology Assessment, and Epidemiology and GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands; Department of Internal Medicine, Máxima Medical Centre, Veldhoven, The Netherlands; Department of Internal Medicine, Atrium Medical Centre Parkstad, Heerlen, The Netherlands; Department of Internal Medicine, Orbis Medical Centre, Sittard, The Netherlands; Department of Internal Medicine, VieCuri Medical Centre, Venlo, The Netherlands; Biostatistics, Department for Health Evidence, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Bart
authors.initials: B
authors.lastname: de Vries
authors.affiliation: Departments of Medical Oncology, Pathology, Clinical Epidemiology and Medical Technology Assessment, and Epidemiology and GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands; Department of Internal Medicine, Máxima Medical Centre, Veldhoven, The Netherlands; Department of Internal Medicine, Atrium Medical Centre Parkstad, Heerlen, The Netherlands; Department of Internal Medicine, Orbis Medical Centre, Sittard, The Netherlands; Department of Internal Medicine, VieCuri Medical Centre, Venlo, The Netherlands; Biostatistics, Department for Health Evidence, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Manuela A
authors.initials: MA
authors.lastname: Joore
authors.affiliation: Departments of Medical Oncology, Pathology, Clinical Epidemiology and Medical Technology Assessment, and Epidemiology and GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands; Department of Internal Medicine, Máxima Medical Centre, Veldhoven, The Netherlands; Department of Internal Medicine, Atrium Medical Centre Parkstad, Heerlen, The Netherlands; Department of Internal Medicine, Orbis Medical Centre, Sittard, The Netherlands; Department of Internal Medicine, VieCuri Medical Centre, Venlo, The Netherlands; Biostatistics, Department for Health Evidence, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Petronella G M
authors.initials: PG
authors.lastname: Peer
authors.affiliation: Departments of Medical Oncology, Pathology, Clinical Epidemiology and Medical Technology Assessment, and Epidemiology and GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands; Department of Internal Medicine, Máxima Medical Centre, Veldhoven, The Netherlands; Department of Internal Medicine, Atrium Medical Centre Parkstad, Heerlen, The Netherlands; Department of Internal Medicine, Orbis Medical Centre, Sittard, The Netherlands; Department of Internal Medicine, VieCuri Medical Centre, Venlo, The Netherlands; Biostatistics, Department for Health Evidence, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Adri C
authors.initials: AC
authors.lastname: Voogd
authors.affiliation: Departments of Medical Oncology, Pathology, Clinical Epidemiology and Medical Technology Assessment, and Epidemiology and GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands; Department of Internal Medicine, Máxima Medical Centre, Veldhoven, The Netherlands; Department of Internal Medicine, Atrium Medical Centre Parkstad, Heerlen, The Netherlands; Department of Internal Medicine, Orbis Medical Centre, Sittard, The Netherlands; Department of Internal Medicine, VieCuri Medical Centre, Venlo, The Netherlands; Biostatistics, Department for Health Evidence, Radboud University Medical Center, Nijmegen, The Netherlands vcg.tjan.heijnen@mumc.nl.
authors.forename: Vivianne C G
authors.initials: VC
authors.lastname: Tjan-Heijnen
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy*; D017024:Chemotherapy, Adjuvant; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D009426:Netherlands; D000068878:Trastuzumab / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D000970:Antineoplastic Agents; D000068878:Trastuzumab
keywords: Early breast cancer; Effectiveness; Real life; Trastuzumab