title: Tumour-infiltrating CD8+ lymphocytes as an independent predictive factor for pathological complete response to primary systemic therapy in breast cancer.
abstract: BACKGROUND
  Tumour-infiltrating lymphocytes (TILs) are known to be associated with response to primary systemic therapy (PST) in breast cancer. This study was conducted to assess the association of TIL subsets with pathological complete response (pCR) after PST in breast cancer in relation to breast cancer subtype, breast cancer stem cell (BCSC) phenotype and epithelial-mesenchymal transition (EMT).
  
  
  METHODS
  The pre-chemotherapeutic biopsy specimens of 153 breast cancer patients who underwent surgical resection after anthracycline- or anthracycline/taxane-based PST were analysed. TIL subsets (CD4+, CD8+, and FOXP3+ TILs), BCSC phenotype, and the expression of EMT markers were evaluated by immunohistochemistry and were correlated with pCR after PST.
  
  
  RESULTS
  Infiltration of CD4+ and CD8+ T lymphocytes was closely correlated with BCSC phenotype and EMT. High levels of CD4+, CD8+, and FOXP3+ TILs were associated with pCR, and CD8+ TILs were found to be an independent predictive factor for pCR. In addition, CD8+ TILs were associated with pCR irrespective of breast cancer subtype, CD44+/CD24- phenotype, EMT, and chemotherapeutic regimen in subgroup analyses.
  
  
  CONCLUSIONS
  These findings indicate that CD8+ cytotoxic T lymphocytes are a key component of TILs associated with chemo-response and can be used as a reliable predictor of response to anthracycline- or anthracycline/taxane-based PST in breast cancer.
authors.affiliation: 1] Department of Pathology, Seoul National University Bundang Hospital, 300 Gumi-dong, Bundang-gu, Seongnam-si, Gyeonggi 463-707, Korea [2] Department of Pathology, Kyungpook National University School of Medicine, 680 Gukchaebosang-ro, Jung-gu, Daegu 700-842, Korea.
authors.forename: A N
authors.initials: AN
authors.lastname: Seo
authors.forename: H J
authors.initials: HJ
authors.lastname: Lee
authors.forename: E J
authors.initials: EJ
authors.lastname: Kim
authors.forename: H J
authors.initials: HJ
authors.lastname: Kim
authors.forename: M H
authors.initials: MH
authors.lastname: Jang
authors.forename: H E
authors.initials: HE
authors.lastname: Lee
authors.forename: Y J
authors.initials: YJ
authors.lastname: Kim
authors.forename: J H
authors.initials: JH
authors.lastname: Kim
authors.forename: S Y
authors.initials: SY
authors.lastname: Park
mesh_terms: D000328:Adult; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000276:immunology; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology* / Q000601:surgery; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000473:pathology / Q000502:physiology*; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D016246:Lymphocytes, Tumor-Infiltrating / Q000187:drug effects / Q000473:pathology / Q000502:physiology*; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D011379:Prognosis; D012074:Remission Induction; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor