title: Prognostic Value of MammaPrint®in Invasive Lobular Breast Cancer.
abstract: BACKGROUND
  MammaPrint® is a microarray-based gene expression test cleared by the US Food and Drug Administration to assess recurrence risk in early-stage breast cancer, aimed to guide physicians in making neoadjuvant and adjuvant treatment decisions. The increase in the incidence of invasive lobular carcinomas (ILCs) over the past decades and the modest representation of ILC in the MammaPrint development data set calls for a stratified survival analysis dedicated to this specific subgroup.
  
  
  OBJECTIVE
  The current study aimed to validate the prognostic value of the MammaPrint test for breast cancer patients with early-stage ILCs.
  
  
  METHODS
  Univariate and multivariate survival associations for overall survival (OS), distant metastasis-free interval (DMFI), and distant metastasis-free survival (DMFS) were studied in a study population of 217 early-stage ILC breast cancer patients from five different clinical studies.
  
  
  CONCLUSIONS
  A significant association between MammaPrint High Risk and poor clinical outcome was shown for OS, DMFI, and DMFS. A subanalysis was performed on the lymph node-negative study population. In the lymph node-negative study population, we report an up to 11 times higher change in the diagnosis of an event in the MammaPrint High Risk group. For DMFI, the reported hazard ratio is 11.1 (95% confidence interval = 2.3-53.0).
  
  
  CONCLUSIONS
  Study results validate MammaPrint as an independent factor for breast cancer patients with early-stage invasive lobular breast cancer. Hazard ratios up to 11 in multivariate analyses emphasize the independent value of MammaPrint, specifically in lymph node-negative ILC breast cancers.
authors.affiliation: Agendia NV, Science Park, Amsterdam, the Netherlands.
authors.forename: Inès J
authors.initials: IJ
authors.lastname: Beumer
authors.affiliation: Agendia NV, Science Park, Amsterdam, the Netherlands.
authors.forename: Marion
authors.initials: M
authors.lastname: Persoon
authors.affiliation: Agendia NV, Science Park, Amsterdam, the Netherlands.
authors.forename: Anke
authors.initials: A
authors.lastname: Witteveen
authors.affiliation: Agendia NV, Science Park, Amsterdam, the Netherlands.
authors.forename: Christa
authors.initials: C
authors.lastname: Dreezen
authors.affiliation: Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Cambridge, UK.
authors.forename: Suet-Feung
authors.initials: SF
authors.lastname: Chin
authors.affiliation: Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Cambridge, UK.
authors.forename: Stephen-John
authors.initials: SJ
authors.lastname: Sammut
authors.affiliation: Agendia NV, Science Park, Amsterdam, the Netherlands.
authors.forename: Mireille
authors.initials: M
authors.lastname: Snel
authors.affiliation: Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Cambridge, UK.
authors.forename: Carlos
authors.initials: C
authors.lastname: Caldas
authors.affiliation: Division of Molecular Pathology, Netherlands Cancer Institute, Plesmanlaan, Amsterdam, the Netherlands.; Division of Medical Oncology, Netherlands Cancer Institute, Plesmanlaan, Amsterdam, the Netherlands.; Department of Pathology, University Medical Center Utrecht, Heidelberglaan, Utrecht, the Netherlands.
authors.forename: Sabine
authors.initials: S
authors.lastname: Linn
authors.affiliation: Agendia NV, Science Park, Amsterdam, the Netherlands.; Helen Diller Family Comprehensive Cancer Center, University of California at San Francisco, San Francisco, CA, USA.
authors.forename: Laura J
authors.initials: LJ
authors.lastname: van 't Veer
authors.affiliation: Agendia NV, Science Park, Amsterdam, the Netherlands.; Division of Molecular Carcinogenesis, Cancer Genomics Centre, Utrecht, the Netherlands.; Division of Molecular Carcinogenesis, Cancer Genomics Centre Netherlands. Netherlands Cancer Institute, Amsterdam, the Netherlands.
authors.forename: Rene
authors.initials: R
authors.lastname: Bernards
authors.affiliation: Agendia NV, Science Park, Amsterdam, the Netherlands.
authors.forename: Annuska M
authors.initials: AM
authors.lastname: Glas
keywords: MammaPrint; breast cancer; clinical prognostic value; diagnostic test; invasive lobular carcinoma; microarray