title: Association of HER2 Overexpression and Prognosis in Small (T1N0) Primary Breast Cancers.
abstract: BACKGROUND
  There is some controversy regarding the precise role and need for adjuvant therapy in patients with pT1a/pT1bN0 breast cancer, although studies have indicated that a HER2-positive status is one of the most powerful poor prognostic factors.
  
  
  METHODS
  We retrospectively evaluated disease-free survival (DFS), distant disease-free survival (DDFS), and overall survival (OS) among 960 patients diagnosed between 2000 and 2008 with T1N0 primary breast cancer treated at 3 German centers, and determined prognostic risk factors. Univariate analysis was used to determine associations with potential risk factors.
  
  
  RESULTS
  With a median follow-up of 23 months, DFS was 94.8%, DDFS 96.3%, and OS 97.5%. Risk factors for decreased 1-year DFS were: peritumoral lymphatic invasion (L1) (p = 0.031), negative hormone receptor status (p = 0.003), non-use of hormonal therapy (p = 0.001), and a positive HER2 status (p = 0.003). Amongst the HER2-positive patients only 2.7% (n = 1/37) of those treated with trastuzumab had a DFS event compared with 20% (n = 10/50) without trastuzumab.
  
  
  CONCLUSIONS
  Patients with HER2-positive T1 breast cancer should be considered for inclusion in prospective trials of trastuzumab in combination with chemotherapy to determine the risk-to-benefit ratio and association with other prognostic factors.
authors.affiliation: Universitäts-Frauenklinik, Universität Heidelberg, Deutschland.
authors.forename: Joachim
authors.initials: J
authors.lastname: Rom
authors.affiliation: Brustzentrum, St. Elisabeth Krankenhaus, Köln, Deutschland.
authors.forename: Claudia
authors.initials: C
authors.lastname: Schumacher
authors.affiliation: Brustzentrum, Bethesda Krankenhaus, Wuppertal, Deutschland.
authors.forename: Oleg
authors.initials: O
authors.lastname: Gluz
authors.affiliation: Staburo GmbH, München, Deutschland.
authors.forename: Josef
authors.initials: J
authors.lastname: Höfler
authors.affiliation: Institut für Pathologie, St. Elisabeth Krankenhaus, Köln, Deutschland.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Eidt
authors.affiliation: Universitäts-Frauenklinik, Universität Heidelberg, Deutschland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Domschke
authors.affiliation: Universitäts-Frauenklinik, Universität Heidelberg, Deutschland ; National Centrum für Tumorerkrankungen, Universität Heidelberg, Deutschland.
authors.forename: Frederik
authors.initials: F
authors.lastname: Marmé
authors.affiliation: Brustzentrum, Bethesda Krankenhaus, Wuppertal, Deutschland.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Nitz
authors.affiliation: Universitäts-Frauenklinik, Universität Heidelberg, Deutschland.
authors.forename: Christof
authors.initials: C
authors.lastname: Sohn
authors.affiliation: Universitäts-Frauenklinik, Universität Heidelberg, Deutschland ; National Centrum für Tumorerkrankungen, Universität Heidelberg, Deutschland.
authors.forename: Andreas
authors.initials: A
authors.lastname: Schneeweiss
keywords: Adjuvant treatment; Disease-free survival; HER2/neu; High-risk breast cancer; Trastuzumab