title: Characteristics and clinical outcome of T1 breast cancer: a multicenter retrospective cohort study.
abstract: BACKGROUND
  A subgroup of T1N0M0 breast cancer (BC) carries a high potential of relapse, and thus may require adjuvant systemic therapy (AST).
  
  
  METHODS
  Retrospective analysis of all patients with T1 BC, who underwent surgery from January 1999 to December 2009 at 13 French sites. AST was not standardized.
  
  
  RESULTS
  Among 8100 women operated, 5423 had T1 tumors (708 T1a, 2208 T1b and 2508 T1c 11-15 mm). T1a differed significantly from T1b tumors with respect to several parameters (lower age, more frequent negative hormonal status and positive HER2 status, less frequent lymphovascular invasion), exhibiting a mix of favorable and poor prognosis factors. Overall survival was not different between T1a, b or c tumors but recurrence-free survival was significantly higher in T1b than in T1a tumors (P = 0.001). In multivariate analysis, tumor grade, hormone therapy and lymphovascular invasion were independent prognostic factors.
  
  
  CONCLUSIONS
  Relatively poor outcome of patients with T1a tumors might be explained by a high frequency of risk factors in this subgroup (frequent negative hormone receptors and HER2 overexpression) and by a less frequent administration of AST (endocrine treatment and chemotherapy). Tumor size might not be the main determinant of prognosis in T1 BC.
authors.affiliation: Department of Surgery, Institut Paoli Calmettes, Aix Marseille Université, Marseilleand CRCM. Electronic address: houvenaeghelg@ipc.unicancer.fr.
authors.forename: G
authors.initials: G
authors.lastname: Houvenaeghel
authors.affiliation: Department of Oncology, Institut Paoli Calmettes, Aix Marseille Université, Marseille.
authors.forename: A
authors.initials: A
authors.lastname: Goncalves
authors.affiliation: Department of Surgery, Institut René Gauducheau, Nantes.
authors.forename: J M
authors.initials: JM
authors.lastname: Classe
authors.affiliation: Department of Surgery, Institut Gustave Roussy, Villejuif.
authors.forename: J R
authors.initials: JR
authors.lastname: Garbay
authors.affiliation: Department of Surgery, Centre Oscar Lambret, Lille.
authors.forename: S
authors.initials: S
authors.lastname: Giard
authors.affiliation: Department of Surgery, Centre Claudius Regaud, Toulouse.
authors.forename: H
authors.initials: H
authors.lastname: Charytensky
authors.affiliation: Department of Surgery, Institut Paoli Calmettes, Aix Marseille Université, Marseilleand CRCM.
authors.forename: M
authors.initials: M
authors.lastname: Cohen
authors.affiliation: Department of Surgery, Centre René Huguenin, Saint Cloud.
authors.forename: C
authors.initials: C
authors.lastname: Belichard
authors.affiliation: Department of Surgery, Centre Léon Bérard, Lyon.
authors.forename: C
authors.initials: C
authors.lastname: Faure
authors.affiliation: Department of Surgery, Hôpital Tenon, Paris.
authors.forename: S
authors.initials: S
authors.lastname: Uzan
authors.affiliation: Department of Surgery, Centre Georges François Leclerc, Dijon.
authors.forename: D
authors.initials: D
authors.lastname: Hudry
authors.affiliation: Department of Surgery, Hôpital de Grasse, Grasse.
authors.forename: P
authors.initials: P
authors.lastname: Azuar
authors.affiliation: Department of Surgery, Hôpital des Diaconnesses, Paris.
authors.forename: R
authors.initials: R
authors.lastname: Villet
authors.affiliation: Department of Surgery, Centre Jean Perrin, Clermont Ferrand.
authors.forename: P
authors.initials: P
authors.lastname: Gimbergues
authors.affiliation: Department of Surgery, Institut Bergonié, Bordeaux.
authors.forename: C
authors.initials: C
authors.lastname: Tunon de Lara
authors.affiliation: Department of Surgery, Institut Paoli Calmettes, Aix Marseille Université, Marseilleand CRCM.
authors.forename: M
authors.initials: M
authors.lastname: Martino
authors.affiliation: Department of Surgery, Institut Paoli Calmettes, Aix Marseille Université, Marseilleand CRCM.
authors.forename: E
authors.initials: E
authors.lastname: Lambaudie
authors.affiliation: Department of Surgery, Centre Georges François Leclerc, Dijon.
authors.forename: C
authors.initials: C
authors.lastname: Coutant
authors.affiliation: Department of Surgery, Institut René Gauducheau, Nantes.
authors.forename: F
authors.initials: F
authors.lastname: Dravet
authors.affiliation: Department of Surgery, Centre Oscar Lambret, Lille.
authors.forename: M P
authors.initials: MP
authors.lastname: Chauvet
authors.affiliation: Department of Surgery, Institut Paoli Calmettes, Aix Marseille Université, Marseilleand CRCM; Department of Surgery, Hôpital Tenon, Paris.
authors.forename: E
authors.initials: E
authors.lastname: Chéreau Ewald
authors.affiliation: Department of Pathology, Centre Jean Perrin, Clermont Ferrand.
authors.forename: F
authors.initials: F
authors.lastname: Penault-Llorca
authors.affiliation: Biostatistic, Department of Surgery, Institut Paoli Calmettes, Marseilleand CRCM, France.
authors.forename: B
authors.initials: B
authors.lastname: Esterni
mesh_terms: D000277:Adjuvants, Pharmaceutic / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000401:mortality*; D015331:Cohort Studies; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
chemical_list: D000277:Adjuvants, Pharmaceutic; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C508053:ERBB2 protein, human
keywords: T1N0M0; adjuvant systemic therapy; breast cancer; prognosis