title: Tumour infiltrating lymphocytes (TILs) in breast cancer during pregnancy.
abstract: BACKGROUND
  Tumour infiltrating lymphocytes (TILs) is one of the most exciting breast cancer biomarkers, yet no data is available on its prevalence in tumours diagnosed during pregnancy.
  
  
  METHODS
  We evaluated the prevalence of TILs (stromal and intratumoural) in pregnant and non-pregnant young breast cancer patients.
  
  
  RESULTS
  11/116 (9.6%) of the non-pregnant and 2/86 (2.3%) pregnant patients had TILs ≥ 50% (p < 0.001) with highest prevalence observed in triple negative tumours (p = 0.01).
  
  
  CONCLUSIONS
  This is the first report on TILs in tumours diagnosed during pregnancy. The low prevalence could reflect the state of low host immunity associated with pregnancy.
authors.affiliation: BrEAST Data Centre, Department of Medicine, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium. Electronic address: hatem.azim@bordet.be.
authors.forename: Hatem A
authors.initials: HA
authors.lastname: Azim
authors.affiliation: Division of Pathology, European Institute of Oncology, Milan, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Vingiani
authors.affiliation: Fertility and Procreation Unit, Department of Gynecology Oncology, European Institute of Oncology, Milan, Italy.
authors.forename: Fedro
authors.initials: F
authors.lastname: Peccatori
authors.affiliation: Division of Pathology, European Institute of Oncology, Milan, Italy; University of Milan, School of Medicine, Milan, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Viale
authors.affiliation: Division of Clinical Medicine and Research, Peter MacCallum Cancer Centre, University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: Sherene
authors.initials: S
authors.lastname: Loi
authors.affiliation: Division of Pathology, European Institute of Oncology, Milan, Italy; University of Milan, School of Medicine, Milan, Italy.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Pruneri
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000276:immunology* / Q000473:pathology; D005260:Female; D006801:Humans; D007111:Immunity, Cellular; D016246:Lymphocytes, Tumor-Infiltrating / Q000166:cytology*; D008875:Middle Aged; D011247:Pregnancy; D011252:Pregnancy Complications, Neoplastic / Q000276:immunology* / Q000473:pathology; D055815:Young Adult
keywords: Biology; Breast cancer during pregnancy; Tumour infiltrating lymphocytes; Young